Carrier 38Au Users Manual 09SI

38AU to the manual c37178b3-8344-4c06-a11a-0df7c3c65dfd

2015-01-24

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38AU

Air Cooled Condensing Units

60 Hz

With PuronR(R---410A) Refrigerant

S i z e s 1 6 --- 2 5

Installation, Start---Up and

Service Instructions

CONTENTS

SAFETY CONSIDERATIONS 2....................

INSTALLATION GUIDELINES 2..................

Replacement/Retrofit — R--22 to Puron 2...........

INSTALLATION 11 - 22.........................

Jobsite Survey 11...............................

Step 1 -- Plan for Unit Location 11.................

Step 2 -- Complete Pre--Installation Checks 11........

Step3–PrepareUnitMounting Support 12..........

Step4–RigandMount the Unit 12................

Step5–CompleteRefrigerantPipingConnections 12...

Step6–InstallAccessories 17....................

Step7–CompleteElectricalConnections 18.........

PRE-START-UP 23...............................

System Check 23...............................

Turn On Crankcase Heater 23.....................

Preliminary Charge 23...........................

START--UP 23 - 31..............................

Preliminary Checks 23...........................

Start Unit 24...................................

OPERATING SEQUENCE 32......................

Indoor (Supply) Fan 32..........................

Cooling, Unit Without Economizer 32..............

Cooling, Unit With Economizer 32.................

Heating 32....................................

ROUTINE SYSTEM MAINTENANCE 33............

Quarterly Inspection (and 30 days after initial start) 33...

Seasonal Maintenance 33........................

SERVICE 33 - 44................................

Refrigeration System 33.........................

Compressor Oil 33..............................

Servicing Systems on Roofs with

Synthetic Materials 33...........................

Liquid Line Filter Drier 34.......................

Field Refrigerant Access Ports 34..................

Factory High--Flow Access Ports 34................

Comfort Alert Diagnostic Module 35...............

Compressor Protection 37........................

Crankcase Heater 37............................

Low--Pressure Switch 37.........................

High--Pressure Switch 37.........................

Outdoor Fans 37................................

Lubrication 37.................................

Coil Type Identification 42.......................

NOVATIONtCoil Cleaning and Maintenance 42.....

Repairing NOVATION Condenser Tube Leaks 42.....

Replacing NOVATION Condenser Coil 43...........

Routine Cleaning of Round-Tube Plate Fin

(RTPF) Coils 43................................

Fastener Torque Values 44........................

TROUBLESHOOTING 44 -- 45.....................

APPENDIX A

Air Conditioner & Heat Pump with PuronR—

Quick Reference Guide 46.........................

APPENDIX B

Wiring Diagram List 46...........................

APPENDIX C

Low Ambient Option — Factory Installed 47..........

START--UP CHECKLIST 55 -- 56...................

SAFETY CONSIDERATIONS

Improper installation, adjustment, alteration, service,

maintenance, or use can cause explosion, fire, electrical

shock or other conditions which may cause personal

injury or property damage. Consult a qualified installer,

service agency, or your distributor or branch for

information or assistance. The qualified installer or

agency must use factory-authorized kits or accessories

when modifying this product. Refer to the individual

instructions package

Follow all safety codes. Wear safety glasses and work

gloves. Use quenching cloths for brazing operations and

have a fire extinguisher available. Read these instructions

thoroughly and follow all warnings or cautions attached to

the unit. Consult local building codes and appropriate

national electrical codes (in USA, ANSI/NFPA70,

National Electrical Code (NEC); in Canada, CSA C22.1)

for special requirements.

It is important to recognize safety information. This is the

safety--alert symbol . When you see this symbol on the

unit and in instructions or manuals, be alert to the

potential for personal injury.

Understand the signal words DANGER, WARNING,

CAUTION, and NOTE. These words are used with the

safety-alert symbol. DANGER identifies the most serious

hazards which will result in severe personal injury or

death. WARNING signifies hazards which could result in

personal injury or death. CAUTION is used to identify

unsafe practices, which may result in minor personal

injury or product and property damage. NOTE is used to

highlight suggestions which will result in enhanced

installation, reliability, or operation.

ELECTRICAL SHOCK HAZARD

Failure to follow this warning could cause in personal

injury or death.

Before performing service or maintenance operations

on unit, always turn off main power switch to unit and

install lockout tag. Unit may have more than one

power switch.

!WARNING

UNIT OPERATION AND SAFETY HAZARD

Failure to follow this warning could cause in personal

injury,death and/or equipment damage.

PuronR(R--410A) refrigerant systems operate at

higher pressures than standard R--22 systems. Do not

use R--22 service equipment or components on Puron

refrigerant equipment.

!WARNING

PERSONAL INJURY AND ENVIRONMENTAL

HAZARD

Failure to follow this warning could cause in personal

injury or death.

Relieve pressure and recover all refrigerant before

system repair or final unit disposal.

Wear safety glasses and gloves when handling

refrigerants. Keep torches and other ignition sources

away from refrigerants and oils.

!WARNING

CUT HAZARD

Failure to follow this caution may result in personal

injury.

Sheet metal parts may have sharp edges or burrs. Use

care and wear appropriate protective clothing, safety

glasses and gloves when handling parts and servicing

38AU units.

CAUTION

INSTALLATION GUIDELINE

Replacement/Retrofit — R--22 to PuronR

Replacement/retrofit installations require change-out of

outdoor unit, metering device, and filter driers.

Change-out of indoor coil (evaporator) and

interconnecting tubing is recommended.

Existing evaporator coil – If the existing evaporator coil

may be re-used, check with the coil manufacturer to verify

the coil construction is suitable for operation with the

higher pressures of PuronR(R-410A). Also determine if

the existing TXV valve is compatible with R-410A,

replace if necessary. The minimum factory test pressure

rating must be 250 psig (1725 kPa). Existing coil will

need to be purged with Nitrogen to remove as much

mineral oil as possible to eliminate cross contamination of

oils.

Acid test – If the existing system is being replaced

because of a compressor electrical failure, assume acid is

in system. If system is being replaced for any other

reason, use an approved acid test kit to determine acid

level. If even low levels of acid are detected, install a 100

percent activated alumina suction-line filter drier in

addition to the replacement liquid-line filter drier.

Remove the suction line filter drier as soon as possible,

with a maximum of 72 hr of operation. Recommendation:

Install a ball valve in the liquid line at the filter drier

location when installing a suction filter in the suction line.

Existing refrigeration piping – Reuse of existing refrigerant

piping involves three issues: quality (strength) of existing

tubing, cleanliness and tube size. Inspect all tube segments

and joints for signs of damage, corrosion or poor brazing.

Flush the interconnecting piping system with dry Nitrogen to

eliminate as much trace of mineral oil as possible.

38AU

Same tube sizes are capable of handling higher flowrates

(expressed as tons of cooling capacity) with Puron

refrigerant compared to R--22 at constant pressure drops.

For example, a 1/2--inch OD liquid line is rated at 33%

higher tons with PuronRthan with R--22 (at 5_F pressure

drop). A 1 1/8--inch OD suction line is rated at 53% higher

tons with Puron than with R--22 (at 2_F pressure drop).

Refrigeration lines selected for R--22 use are typically

oversized for Puron applications. Carefully check the

existing suction line size against the table for maximum size

(see Table 7); replace vertical riser segments if necessary.

Check existing liquid line size against sizing data in Table 5

or 6; replace with smaller lines when feasible.

Installation –

1. Remove the existing evaporator coil or fan coil and

install the replacement coil when appropriate.

2. Drain oil from low points and traps in suction line

tubing (and hot gas bypass tubing if appropriate) and

evaporator if they were not replaced. Removing oil

from evaporator coil may require purging of the

tubing with dry nitrogen.

3. Unless indoor unit is equipped with a Puron®ap-

proved metering device, change the metering device

to a thermal expansion valve (TXV) designed for

PuronR(R-410A).

4. Remove the existing outdoor unit. Install the new out-

door unit according to these installation instructions.

5. Install a new field-supplied liquid-line filter drier at

the indoor coil just upstream of the TXV or fix orifice

metering device.

6. If a suction line filter drier is also to be installed, in-

stall suction line drier downstream of suction line ser-

vice valve at condensing unit.

UNIT DAMAGE HAZARD

Failure to follow this caution may result in equipment

damage or improper operation.

Never install suction--line filter drier in the liquid--line

of a PuronRsystem.

CAUTION

7. If required, install a 100% activated alumina suction

line filter drier at the outdoor unit.

8. Evacuate and charge the system according to the in-

structions in this installation manual.

9. Operate the system for 10 hr. Monitor the pressure

drop across the suction line filter drier. If pressure

drop exceeds 3 psig (21kPa), replace suction-line and

liquid-line filter driers. Be sure to purge system with

dry nitrogen and evacuate when replacing filter

driers. Continue to monitor the pressure drop across

suction-line filter drier. Repeat filter changes is neces-

sary. Never leave suction-line filter drier in system

longer than 72 hr (actual time).

38AU

C10942

UNIT Standard

Weight

Corner

DCenter of Gravity Unit

Height

lbs. kg. lbs. kg. lbs. kg. lbs. kg. lbs. kg. X Y Z H

38AUZ*16

(MCHX) 633 288 220 100 134 61 135 61 144 65.5 38

[965.2]

[482.6]

[381]

50 3/8

[1279.2]

38AUD*16

(MCHX) 633 288 220 100 134 61 135 61 144 65.5 38

[965.2]

[482.6]

[381]

50 3/8

[1279.2]

38AUZ*16

(RTPF) 731 332 237 107 172 78 135 61 186 84 38

[965.2]

[482.6]

[431.8]

50 3/8

[1279.2]

38AUD*16

(RTPF) 731 332 237 107 172 78 135 61 186 84 38

[965.2]

[482.6]

[431.8]

50 3/8

[1279.2]

LEGEND: MCXH = Novation™ coil

RTPF = Round Tube/Plate Fin coil

Fig. 1 -- 38AU**16 Unit Dimensions

38AU

C10943

UNIT Standard

Weight

Corner

DCenter of Gravity Unit

Height

lbs. kg. lbs. kg. lbs. kg. lbs. kg. lbs. kg. X Y Z H

38AUZ*25

(RTPF) 978 444 360 163 188 85 147 67 283 128 38

[965.2] 23

[584.2] 17

[431.8] 50 3/8

[1279.2]

38AUD*25

(RTPF) 978 444 360 163 188 85 147 67 283 128 38

[965.2] 23

[584.2] 17

[431.8] 50 3/8

[1279.2]

LEGEND: RTPF = Round Tube/Plate Fin coil

Fig. 2 -- 38AU**25 Unit Dimensions

38AU

Table 1A — Physical Data — 38AUZ*16-25 Units — 60 Hz English

UNIT SIZE 38AU Z*16 Z*25

NOMINAL CAPACITY (tons) 15 20

OPERATING WEIGHTS (lb)

NOVATION™Coil (Al Tube) 633 ---

Round Tube/Plate Fin Coil (Cu/Al) 731 900

REFRIGERANT TYPE‡R-410A

NOVATION Operating Charge, Typical (lb)†24.6 ---

NOVATION Shipping Charge (lb) 12.2 ---

RTPF Operating Charge, Typical (lb)†43.0 38.0

RTPF Shipping Charge (lb) 32.0 28.0

COMPRESSOR

Qty...Type 2...Scroll 2...Scroll

Oil Charge (oz) 60 110

CONDENSER FANS

Qty...Rpm 3...1100 4...1100

Motor Hp 1/41/4

Diameter 22 22

Nominal Airflow (Cfm Total) 9,000 12,000

Watts (Total) 970 1150

RTPF CONDENSER COIL

Material (Tube/Fin) Cu / Al Cu / Al

Coil Type 3/8--- i n R T P F 3/8--- i n R T P F

Rows/Fins per inch (FPI) 2/17 2/17

Face Area (sq ft total) 47.0 50.0

NOVATION CONDENSER COIL

Material (Tube/Fin) Al / Al ---

Coil Type Novation ---

Rows/Fins per inch (FPI) 1/17 ---

Face Area (sq ft total) 50.0 ---

CONTROLS

Pressurestat Settings (psig)

High Cutout 630 ±10

Cut-in 505 ±20

Low Cutout 54 ±3

Cut-in 117 ±5

PIPING CONNECTIONS (in. ODS)

Qty...Suction 1...13/81...15/8

Qty...Liquid 1...5/81...5/8

LEGEND

RTPF — Round Tube/Plate Fin

ODS — Outside Diameter Sweat (socket)

‡Unit is factory-supplied with partial charge only.

†Typical operating charge with 25 ft of interconnecting piping.

38AU

Table 1B — Physical Data — 38AUZ*16-25 Units — 60 Hz SI

UNIT SIZE 38AU Z*16 Z*25

NOMINAL CAPACITY (kW) 52.7 70.3

OPERATING WEIGHT (kg)

NOVATION™Coil (Al Tube) 288 ---

Round Tube/Plate Fin Coil (Cu/Al) 332 409

REFRIGERANT TYPE‡R-410A

NOVATION Operating Charge, Typical (kg)†11.1 ---

NOVATION Shipping Charge (kg) 5.4 ---

RTPF Operating Charge, Typical (kg)†19.5 17.2

RTPF Shipping Charge (kg) 14.5 12.7

COMPRESSOR Scroll

Qty...Type 2...Scroll 2...Scroll

Oil Charge (L) 1.7 3.2

CONDENSER FANS

Qty...r/s 3...18 4...18

Motor Hp NEMA 1/41/4

Diameter (mm) 560 560

Nominal Airflow (L/s) 4248 5663

Watts (Total) 970 1150

RTPF CONDENSER COIL (Qty)

Material (Tube/Fin) Cu / Al Cu / Al

Coil Type 3/8--- i n R T P F 3/8--- i n R T P F

Rows/Fins per Meter (Fins/m) 1...670 2...670

Face Area (sq m total) 4.4 4.6

NOVATION CONDENSER COIL

Material (Tube/Fin) Al / Al ---

Coil Type Novation ---

Rows/Fins per Meter (Fins/m) 1...670 ---

Face Area (sq m total) 4.6 ---

CONTROLS

Pressurestat Settings (kPa)

High Cutout 4347 ±70

Cut-in 3482 ±138

Low Cutout 372 ±21

Cut-in 807 ±34

PIPING CONNECTIONS (mm ODS)

Qty...Suction 1...34.9 1...38.7

Qty...Liquid 1...13.3 1...13.3

LEGEND

RTPF — Round Tube/Plate Fin

NEMA — National Electrical Manufacturers Association

ODS — Outside Diameter Sweat (socket)

‡Unit is factory-supplied with partial charge only.

†Typical operating charge with 7.62 m of interconnecting piping.

38AU

Table 2A — Physical Data — 38AUD*16-25 Units — 60 Hz English

UNIT SIZE 38AU D*16 D*25

NOMINAL CAPACITY (tons) 15 20

OPERATING WEIGHTS (lb)

NOVATION™Coil (Al Tube) 633 ---

Round Tube/Plate Fin Coil (Cu/Al) 731 900

REFRIGERANT TYPE‡R-410A

NOVATION Operating Charge A/B, Typical (lb)†12.0 / 12.0 ---

NOVATION Shipping Charge A/B (lb) 6.0 / 6.0 ---

RTPF Operating Charge A/B, Typical (lb)†22.0 / 22.0 19.0 / 19.0

RTPF Shipping Charge A/B (lb) 16.0 / 16.0 14.0 / 14.0

COMPRESSOR

Qty...Type 2...Scroll 2...Scroll

Oil Charge A/B (oz) 60 / 60 110 / 110

CONDENSER FANS

Qty...Rpm 3...1100 4...1100

Motor Hp 1/4 1/4

Diameter 22 22

Nominal Airflow (Cfm Total) 9,000 12,000

Watts (Total) 970 1150

RTPF CONDENSER COIL

Material (Tube/Fin) Cu / Al Cu / Al

Coil Type 3/8--- i n R T P F 3/8--- i n R T P F

Face Area (sq ft total) 47 50

Rows/Fins per inch (FPI) 2/17 2/17

NOVATION CONDENSER COIL

Material (Tube/Fin) Al / Al ---

Coil Type Novation ---

Face Area (sq ft total) 50 ---

Rows/Fins per inch (FPI) 1/17 ---

CONTROLS

Pressurestat Settings (psig)

High Cutout 630 ±10

Cut-in 505 ±20

Low Cutout 54 ±3

Cut-in 117 ±5

PIPING CONNECTIONS (in. ODS)

Qty...Suction 2...13/82...13/8

Qty...Liquid 2...1/22...1/2

LEGEND

RTPF — Round Tube/Plate Fin

ODS — Outside Diameter Sweat (socket)

‡Unit is factory-supplied with partial charge only.

†Typical operating charge with 25 ft of interconnecting piping.

38AU

Table 2B — Physical Data — 38AUD*16-25 Units — 60 Hz SI

UNIT SIZE 38AU D*16 D*25

NOMINAL CAPACITY (kW) 52.7 70.3

OPERATING WEIGHT (kg)

NOVATION™Coil (Al Tube) 288 ---

Round Tube/Plate Fin Coil (Cu/Al) 332 409

REFRIGERANT TYPE‡R-410A R-410A

NOVATION Operating Charge A/B, Typical (kg)†5.4 / 5.4 ---

NOVATION Shipping Charge A/B (kg) 2.7 / 2.7 ---

RTPF Operating Charge A/B, Typical (kg)†10.0 / 10.0 8.6 / 8.6

RTPF Shipping Charge A/B (kg) 7.3 / 7.3 6.8 / 6.8

COMPRESSOR

Qty...Type 2...Scroll 2...Scroll

Oil Charge A/B (L) 1.7 / 1.7 3.2 / 3.2

CONDENSER FANS

Qty...r/s 3...18 4...18

Motor Hp NEMA 1/41/4

Diameter (mm) 560 560

Nominal Airflow (L/s) 4248 5663

Watts (Total) 970 1150

RTPF CONDENSER COIL (Qty)

Material (Tube/Fin) Cu / Al Cu / Al

Coil Type 3/8--- i n R T P F 3/8--- i n R T P F

Rows/Fins per Meter (Fins/m) 1...670 2...670

Face Area (sq m total) 4.4 4.6

NOVATION CONDENSER COIL

Material (Tube/Fin) Al / Al ---

Coil Type Novation ---

Rows/Fins per Meter (Fins/m) 1...670 ---

Face Area (sq m total) 4.6 ---

CONTROLS

Pressurestat Settings (kPa)

High Cutout 4347 ±70 4347 ±70

Cut-in 3482 ±138 3482 ±138

Low Cutout 372 ±21 372 ±21

Cut-in 807 ±34 807 ±34

PIPING CONNECTIONS (mm ODS)

Qty...Suction 2...34.9 2...34.9

Qty...Liquid 2...12.7 2...12.7

LEGEND

RTPF — Round Tube/Plate Fin

NEMA — National Electrical Manufacturers Association

ODS — Outside Diameter Sweat (socket)

‡Unit is factory-supplied with partial charge only.

†Typical operating charge with 7.62 m of interconnecting piping.

38AU

Model Type

38AU= Carrier Condensing Unit

Puron

R---410A Refrigerant

Type of Coil

D = Dual Circuit, A/C Scroll Compressor

Z = Single Circuit, A/C Scroll Compressor

Refrigerant Options

A = None

B = Low Ambient

Nominal Tonnage

16 = 15 Tons

25 = 20 Tons

Not Used

A = Not Used

Not Used

0 = Not Used

38AUZA25A0G6A0A0A0

1 2 3 4 5 6 7 8 9 101112131415161718

Packaging

0=Standard

1=LTL

Electrical Options

A=None

C = Non-Fused Disconnect

Service Options

0=None

1 = Un-powered Convenience Outlet1=

2 = Powered Convenience Outlet

Not Used

A=PlaceHolder

Design Rev

A = Initial Release

Voltage

1 = 575/3/60

5 = 208/ 230/3/60

6 = 460/3/60

Coil Options

NOVATION™ (Size 16 only)

G= Al/Al

K = E-Coat Al/Al

T = Al/Al with Hail Guard

W= E-Coat Al/Al with Hail Guard

RTPF (Sizes 16 & 25)

A= Cu/Al

B = Precoat (Cu/Al)

C = E-Coat (Cu/Al)

M= Cu/Al with Hail Guard

N = Precoat (Cu/Al) with Hail Guard

P = E-Coat (Cu/Al) with Hail Guard

Base Unit Controls

0 = Electro-Mechanical Controls

C10944

Fig. 3 -- Model Number Nomenclature

12345678910

0510U12345

POSITION NUMBER

TYPICAL

POSITION

1 – 2

3 – 4

6 – 10

DESIGNATES

Week of manufacture (fiscal calendar)

Year of manufacture ("10" = 2010)

Manufacturing location (U = Monterrey, Mexico)

Sequence number

C101041

Fig. 4 -- Serial Number Nomenclature

38AU

Matching 38AU Model To Evaporator Coil

The Model 38AUZ is a single-circuit unit design,

requiring one set of refrigeration piping. This model can

be connected to an evaporator coil with one circuit or with

two circuits (by manifolding the evaporator connections

into a single piping system).

The Model 38AUD is a dual-circuit unit design that

requires two sets of refrigeration piping between the

outdoor unit and the evaporator coil (or coils). This model

can only be connected to an evaporator coil that has two

refrigeration circuits (or to two separate evaporator coils).

The Model 38AUD CANNOT be connected to a

single-circuit evaporator coil. The Model 38AUD

CANNOT be field-converted to a single-circuit design.

Table 3 – Evaporator Coil Connections

Evaporator Coil has Connect to Model Notes

Single Circuit 38AUZ ONLY

Two Circuits

38AUZ Manifold evaporator

circuits into single

piping system

38AUD Use two separate

piping systems

Before unpacking this new 38AU model, compare the

evaporator coil design to the 38AU model.

.INSTALLATION

Jobsite Survey

Complete the following checks before installation.

1. Consult local building codes and the NEC (National

Electrical Code) ANSI/NFPA 70 for special installa-

tion requirements.

2. Determine unit location (from project plans) or select

unit location.

3. Check for possible overhead obstructions which may

interfere with unit lifting or rigging.

Step 1 — Plan for Unit Location

Select a location for the unit and its support system (pad,

rails or other) that provides for the minimum clearances

required for safety. This includes the clearance to

combustible surfaces, unit performance and service access

below, around and above unit as specified in unit

drawings. See Fig. 5.

NOTE: Consider also the effect of adjacent units on

airflow performance and control box safety clearance.

Do not install the outdoor unit in an area where fresh air

supply to the outdoor coil may be restricted or when

recirculation from the condenser fan discharge is possible.

Do not locate the unit in a well or next to high walls.

Evaluate the path and required line length for

interconnecting refrigeration piping, including suction

riser requirements (outdoor unit above indoor unit), liquid

line lift (outdoor unit below indoor unit) and hot gas

bypass line. Relocate sections to minimize the length of

interconnecting tubing.

DO NOT BURY REFRIGERATION LINES.

Although unit is weatherproof, avoid locations that permit

water from higher level runoff and overhangs to fall onto

the unit.

LEFT:

Min 18” (457 mm)

requried for service

RIGHT:

Min 18” (457 mm)

requried for service

REAR:

Min 18” (457 mm)

requried for service

Note: Observe requirements for 39” (914 mm) operating clearance

on either Left or Rear coil opening.

FRONT:

42” (1067 mm)

C10201

Fig. 5 -- Service Clearance Dimensional Drawing

Step 2 — Complete Pre-Installation Checks

Check Unit Electrical Characteristics: Confirm before

installation of unit that voltage, amperage and circuit

protection requirements listed on unit data plate agree with

power supply provided.

Un--crate Unit: Remove unit packaging except for the top

skid assembly, which should be left in place until after the

unit is rigged into its final location.

Inspect Shipment: File a claim with shipping company if

the shipment is damaged or incomplete.

Consider System Requirements:

SConsult local building codes and National Electrical

Code (NEC, U.S.A.) for special installation

requirements.

SAllow sufficient space for airflow clearance, wiring,

refrigerant piping, and servicing unit. See Fig.1 and

Fig. 2 for unit dimensions and weight distribution data.

SLocate the unit so that the outdoor coil (condenser)

airflow is unrestricted on all sides and above.

SThe unit may be mounted on a level pad directly on the

base channels or mounted on raised pads at support

points. See Tables 1A through 2B for unit operating

weights. See Fig. 1 and Fig. 2 for weight distribution

based on recommended support points.

NOTE: If vibration isolators are required for a particular

installation, use the data in Fig. 1 and Fig. 2 to make the

proper selection.

38AU

Step 3 — Prepare Unit Mounting Support

Slab Mount —

Provide a level concrete slab that extends a minimum of 6

in. (150 mm) beyond unit cabinet. Install a gravel apron in

front of condenser coil air inlet to prevent grass and

foliage from obstructing airflow.

Step 4 — Rig and Mount the Unit

UNIT DAMAGE HAZARD

Failure to follow this caution may result in equipment

damage.

All panels must be in place when rigging. Unit is not

designed for handling by fork truck.

CAUTION

Rigging: These units are designed for overhead rigging.

Refer to the rigging label for preferred rigging method.

Spreader bars are not required if top crating is left on the

unit. All panels must be in place when rigging. As further

protection for coil faces, plywood sheets may be placed

against the sides of the unit, behind cables. Run cables to

a central suspension point so that the angle from the

horizontal is not less than 45 degrees. Raise and set the

unit down carefully.

If it is necessary to roll the unit into position, mount the

unit on longitudinal rails, using a minimum of 3 rollers.

Apply force to the rails, not the unit. If the unit is to be

skidded into position, place it on a large pad and drag it

by the pad. Do not apply any force to the unit.

Raise from above to lift the unit from the rails or pad

when unit is in its final position.

After the unit is in position, remove all shipping materials

and top crating.

Step 5 — Complete Refrigerant Piping

Connections

IMPORTANT: Do not bury refrigerant piping

underground.

IMPORTANT: A refrigerant receiver is not provided

with the unit. Do not install a receiver.

Provide Safety Relief —

If local codes dictate an additional safety relief device,

purchase locally and install locally. Installation will

require the recovery of the factory shipping charge before

the factory tubing can be cut and the supplemental relief

device is installed.

Model 38AUD has two separate refrigeration systems. If

required, each circuit will require a field-supplied/installed

supplemental relief device.

Table 4 – Equivalent Lengths for Common Fittings (ft)

Nominal

Tube OD

Elbows

90°Std 90°Lrad 90°Street 45°Std 45°Street

3/81.3 0.8 2.2 0.6 1

1/21.4 0.9 2.3 0.7 1.1

5/81.6 12.5 0.8 1.3

3/41.8 1.2 2.9 0.9 1.5

7/821.4 3.2 0.9 1.6

11/82.6 1.7 4.1 1.3 2.1

13/83.3 2.3 5.6 1.7 3

15/842.6 6.3 2.1 3.4

21/853.3 8.2 2.6 4.5

Nominal

Tube OD

Tees

Branch

Flow

Straight-Thru

No Reduct Reduce 25% Reduce 50%

3/82.6 0.8 1.1 1.3

1/22.7 0.9 1.2 1.4

5/83 1 1.4 1.6

3/43.5 1.2 1.7 1.8

7/841.4 1.9 2

11/851.7 2.3 2.6

13/872.3 3.1 3.3

15/882.6 3.7 4

21/810 3.3 4.7 5

Check 38AU Model with Evaporator Coil Connections —

Confirm before installation of unit that the evaporator coil

connections are consistent with this 38AU model. See

Table 3 on page 11.

Determine Refrigerant Line Sizes —

Select the recommended line sizes for 38AUZ and

38AUD unit from the appropriate tables.

Determine the linear length of interconnecting piping

required between the outdoor unit and indoor unit

(evaporator). Consider and identify also the arrangement

of the tubing path (quantity and type of elbows in both

lines), liquid line solenoid size, filter drier and any other

refrigeration specialties located in the liquid line. Refer to

the indoor unit installation instructions for additional

details on refrigeration specialties devices.

Determine equivalent line length adjustments for path and

components and add to linear line lengths. See Table 4,

Equivalent Lengths for Common Fittings, for usual fitting

types. Also identify adjustments for refrigeration

specialties. Refer to Part 3 of the Carrier System Design

Manual for additional data and information on equivalent

lengths.

NOTE: Equivalent line lengths will vary based on tube

diameter. Calculate equivalent line length for each pipe by

adding equivalent length adjustments to linear lengths for

each pipe.

38AU

Enter the appropriate table to select the recommended line

sizes.

Model: Line Sizes Table Quantity of Line Sets

38AUZ 5 1

38AUD 6 2

Liquid Lift —

A liquid lift condition exists when the outdoor unit is

located below the indoor (evaporator) unit and liquid

flows vertically up in a portion of the liquid line. The

vertical column of liquid reduces the available state point

subcooling at the evaporator coil’s thermal expansion

valve. This effect reduces the length of liquid lift (feet of

elevation) that a liquid line size can accommodate.

Longer linear tube lengths will also reduce the amount of

liquid lift possible.

Check Tables 5 (38AUZ) and 6 (38AUD) for maximum

liquid lift capabilities for line sizes. Reselect the liquid

line tube size if necessary. If maximum available tube size

cannot provide the required lift distance on this

installation, relocate the outdoor unit to reduce the

equivalent line length or the lift requirement.

Suction Riser —

A suction riser condition exists when the outdoor unit is

located above the indoor (evaporator) unit and suction

vapor must flow vertically up to return to the compressor.

Oil return is a concern when the suction tube size is too

large to produce the minimum refrigerant velocity to

ensure oil return at minimum load conditions.

Check Table 7 for maximum suction tube size for 38AU

units at minimum load conditions. Consider suction speed

riser (reduced tube size for vertical segment only) or

double suction riser arrangement if the recommended

suction tube size does not provide necessary minimum

flowrates for this riser.

Table 5 – 38AUZ 16-25 Piping Recommendations (Single-Circuit Unit)

R-410A Equivalent Length

Ft 0-38 38-75 75-113 113-150 150-188

m0-12 12-23 23-34 34-46 46-57

Model

Linear Length

Ft 0-25 25-50 50-75 75-100 100-125

m0-8 8-15 15-23 23-30 30-38

38AUZ*16 Liquid Line 5/85/85/85/85/8

Max Lift 25 50 75 100 125

Suction Line 1-1/81-3/81-3/81-3/81-3/81-5/8

Charge (lbs)

Novation 24.3 27.5 30.6 33.7 37.8

RTPF 42.7 45.9 49.0 52.1 56.2

38AUZ*25 Liquid Line 5/85/85/85/85/8

Max Lift 25 50 71 77 63

Suction Line 1-1/81-3/81-3/81-3/81-5/81-5/81-5/8

Charge (lbs) 37.8 40.8 44.6 47.8 51.1

Legend:

Equivalent

Length Equivalent tubing length, including effects of refrigeration specialties devices

Linear Length Typical linear tubing length, (50% added to linear to define Equivalent Length for this table)

Liquid Line Tubing size, inches OD.

Max Lift Maximum liquid lift (indoor unit ABOVE outdoor unit only), at maximum permitted liquid line pressure drop —

SLinear Length Less than 75 ft (23 m): Minimum 2.0° F subcooling entering TXV

SLinear Length Greater than 75 ft (23m): Minimum 0.5° F subcooling entering TXV

Suction Line Tube size, inches OD

Charge Charge Quantity, lbs. Calculated for both liquid line sizes (where applicable), but only with larger suction line size

(where applicable)

NOTE: For applications with equivalent length greater than 188 ft (57 m) and/0r linear length greater than 125 ft (38 m),

contact your local Carrier representative.

38AU

Table 6 – 38AUD 16-25 Piping Recommendations (Two-Circuit Unit)

NOTE: 38AUD requires TWO sets of refrigeration piping

R-410A Equivalent Length

Ft 0-38 38-75 75-113 113-150 150-188

m0-12 12-23 23-34 34-46 46-57

Model

Linear Length

Ft 0-25 25-50 50-75 75-100 100-125

m0-8 8-15 15-23 23-30 30-38

38AUD*16 Liquid Line 1/21/21/21/21/2

Max Lift 25 50 75 100 125

Suction Line 7/811/811/811/811/8

Charge ea. (lbs)

Novation 11.7 13.8 15.7 17.6 19.6

RTPF 21.7 23.8 25.7 27.6 29.6

38AUD*25 Liquid Line 1/21/21/25/81/25/81/25/8

Max Lift 25 50 54 75 60 99 46 95

Suction Line 11/811/811/811/813/813/8

Charge (lbs) 1

19.3

18.3

21.0

20.3

23.0

22.0

26.0

25.0

25.9

24.9

29.7

28.7

28.0

27.0

32.7

31.7

Legend:

Equivalent

Length Equivalent tubing length, including effects of refrigeration specialties devices

Linear Length Typical linear tubing length (50% added to linear to define Equivalent Length for this table)

Liquid Line Tubing size, inches OD.

Max Lift Maximum liquid lift (indoor unit ABOVE outdoor unit only), at maximum permitted liquid line pressure drop —

SLinear Length Less than 75 ft (23 m): Minimum 2.0° F subcooling entering TXV

SLinear Length Greater than 75 ft (23m): Minimum 0.5° F subcooling entering TXV

Suction Line Tube size, inches OD

Charge Charge Quantity, lbs. Calculated for both liquid line sizes (where applicable), but only with larger suction line size

(where applicable)

NOTE: For applications with equivalent length greater than 188 ft (57 m) and/0r linear length greater than 125 ft (38 m),

contact your local Bryant representative.

Table 7 – 38AU Maximum Suction Pipe Size

Model: Unit Size Maximum Tube Size

38AUZ

16 15/8

25 15/8

38AUD

16 15/8

25 15/8

Vertical Separation (outdoor unit above indoor unit) –

Vertical elevation difference of 200 ft (60 m) is permitted

when the outdoor unit (38AUZ or 38AUD) is located

above the indoor unit.

Insulate Suction Lines —

Apply closed-cell tubular insulation to all suction lines

between evaporator coil connection and 38AU unit’s

suction service valve.

Hot Gas Bypass —

Hot gas bypass, if used, should be introduced before the

evaporator. (A bypass route that also bypasses the evaporator

circuit may lead to oil trapping in the evaporator circuit

during low load conditions and then to oil slugging as

evaporator load increases.) Model 38AU units do not include

a hot gas stub connection; a tee must be field-supplied and

installed in the compressor discharge line. Run a 1/2-in OD

line between outdoor unit and evaporator coil inlet. Install an

Auxiliary Side Connector at the evaporator between TXV

and distributor (follow instructions for the side connector

part). Insulate the hot gas line.

38AUD: Generally only one hot gas bypass system will be

applied on a two-circuit unit. Connect the hot gas bypass

system to Circuit 1 (first-on/last-off, connected to the

evaporator coil’s bottom circuit).

38AUD Piping Connections —

The 38AUD’s two circuits are designated Circuit 1 and

Circuit 2. Circuit 1 is controlled by the thermostat’s Y1 (or

TC1) contact and will be the first circuit on and last circuit

off. Circuit 2 is controlled by the thermostat’s Y2 (or TC2)

contact and this circuit is always the “lag” circuit.

See Fig. 6 for location of Circuit 1 and Circuit 2 service

valves and field piping connections. Circuit 1 is on the

left-hand side of the service valve compartment; Circuit 2

is on the right.

When a single piece evaporator coil with two separate

circuits is connected to a 38AUD, the lower coil circuit

should be connected to the 38AUD’s Circuit 1 so that the

evaporator’s lower coil segment is first-on/last-off (to avoid

re-evaporation of condensate on dry lower coil segments).

38AU

Circuit 1

Connections

Circuit 2

Connections

CKT

C10355

Fig. 6 -- 38AUD Service Valve Locations

Plan the Circuit 1 and Circuit 2 tubing segments carefully,

mark each segment and check constantly as piping

systems are assembled to avoid piping errors.

38AUD unit cannot be field-piped as a

single-circuit/tandem system.

Connecting 40RU to 38AUD: The 40RU fan coil in sizes

16, 25 and 28 is a face-split coil design that also has its

circuits designated as 1 and 2. See Fig. 7. Note that the

lower coil segment changes as the arrangement of the

40RU changes. In a vertical arrangement, the 40RU’s

lower coil segment is segment 2; this segment should be

connected to the 38AUD’s Circuit 1. In a horizontal

arrangement, the 40RU’s lower segment is now segment

1; this segment should be connected to the 38AUD’s

Circuit 1.

Note that refrigerant suction piping should be insulated.

40RU

Arrangement

Cooling

Stage

40RU Coil

Segment

Connect to

38AUD

Vertical Y1

Circuit 1

Circuit 2

Horizontal Y1

Circuit 1

Circuit 2

Install Filter Drier(s) and Moisture Indicator(s) —

Every unit MUST have a filter drier in the liquid line.

38AUD models require two filter driers (one in each

liquid line). Locate the filter drier(s) at the indoor unit,

close to the evaporator coil’s thermal expansion valve

(TXV) inlets.

38AU units include one (38AUZ) or two (38AUD)

Puron-duty filter drier(s), shipped in cartons attached to

the unit basepan. Remove the filter drier(s) and prepare to

install in the liquid line(s) at the evaporator coil. Do not

remove connection fitting plugs until ready to connect and

braze the filter drier into the liquid line position.

FIRST ON/LAST OFF = 2

VERTICAL INSTALLATION

FIRST ON/LAST OF F = 1

HORIZONTAL INSTALLATION

C10071

Fig. 7 -- Typical Evaporator Coil Connections (40RU)

Table 8 – Puron-duty Filter Drier(s)

Model-Size Qty Liquid

Line OD

Desiccant

Volume

Part

Number Ref

38AUZ*16 15/8-in 30 cu. in. KH43LG087

38AUZ*25 15/8-in 30 cu. in. KH43LG087

38AUD*16 21/2-in 16 cu. in. KH43LG085

38AUD*25 21/2-in 16 cu. in. KH43LG085

Installation of liquid line moisture indicating sightglass in

each circuit is recommended. Locate the sightglass(es)

between the outlet of the filter drier and the TXV inlet.

Refer to Table 9 for recommendations on refrigeration

specialties.

Table 9 – Refrigerant Specialties Part Numbers.

LIQUID LINE

SIZE (in.)

LIQUID LINE

SOLENOID VALVE (LLSV)

LLSV

COIL

SIGHT

GLASS

FILTER

DRIER

1/2EF680035 EF680037 KM680004 provided with unit

see Table 8

5/8EF680036 EF680037 KM680005

38AUD units require TWO sets of parts.

38AU

INDOOR

COIL CKT 2

AIRFLOW

INDOOR

COIL CKT 1

AIRFLOW

15 DIAMS

MIN 10

DIAMS

8 DIAMS

MIN

TXV

SENSING

BULB

EQUALIZER LINE

SIGHT GLASS

A LOCATION

SIGHT

GLASSES

B LOCATION

TXV

CKT 2

FILTER DRIER

A LOCATION

FILTER

DRIERS

B LOCATION

FLOW

TXV

SENSING

BULB

TXV

CKT 1

8 DIAMS

MIN

15 DIAMS

MIN 10

DIAMS

Single Circuit Coil Piping Configuration

For single compressor condensing units

Dual Circuit Coil Piping Configuration

For single compressor condensing units

15 DIAMS

MIN 10

DIAMS

8 DIAMS

MIN

INDOOR

COIL CKT

AIRFLOW

TXV

SENSING

BULB

EQUALIZER LINE

SIGHT GLASS

A LOCATION

TXV

FILTER DRIER

A LOCATION

LIQUID LINE

SOLENOID

VALVE

FLOW

LIQUID LINE

SOLENOID

VALVE

C10202

Fig. 8 -- Location of Sight Glass(es) and Filter Driers

Typical 38AUZ Systems

AIRFLOW

SUCTION

CIRCUIT 2

SUCTION

CIRCUIT 1

AIRFLOW

15 DIAMS

MIN 10

DIAMS

8 DIAMS

MIN

TXV

SENSING

BULB

EQUALIZER LINE

SIGHT

GLASSES

TXV

CKT 2

FILTER

DRIERS

LIQUID LINE

SOLENOID VALVE

CIRCUIT 2

FLOW

LIQUID LINE

SOLENOID VALVE

CIRCUIT 1

FLOW

TXV

SENSING

BULB

TXV

CKT 1

8 DIAMS

MIN

15 DIAMS

MIN 10

DIAMS

Dual Circuit Coil Piping Configuration

For two circuit condensing units

C10072

Fig. 9 -- Location of Sight Glasses and Filter Driers

Typical 38AUD Systems

In some applications, depending on space and convenience

requirements, it may be desirable to install 2 filter driers and

sight glasses in a single circuit application. One filter drier

and sight glass may be installed at A locations (see Fig. 8) or

2 filter driers and sight glasses may be installed at B

locations (see Figs. 8 and 9).

Select the filter drier for maximum unit capacity and

minimum pressure drop. Complete the refrigerant piping

from the indoor unit to the outdoor unit before opening

the liquid and suction lines at the outdoor unit.

Install Liquid Line Solenoid Valve —

It is recommended that a solenoid valve be placed in the

main liquid line (see Figs. 8 & 9) between the condensing

unit and the evaporator coil. Locate the solenoid valve at the

outlet end of the liquid line, near the evaporator coil

connections, with flow direction arrow pointed at the

evaporator coil. Refer to Table 9. (A liquid line solenoid

valve is required when the liquid line length exceeds 75 ft

[23 m].) This valve prevents refrigerant migration (which

causes oil dilution) to the compressor during the off cycle, at

low outdoor ambient temperatures. Wire the solenoid in

parallel with the compressor contactor coil (see Figs. 8 & 9).

This means of electrical control is referred to as solenoid

drop control.

Solenoid drop control wiring: Control the power to the

liquid line solenoid through a Solenoid Valve Relay (SVR)

in all units. Use part number HN61PC005 (field--supplied,

installed). 38AUZ unit requires one SVR; 38AUD unit

requires two relays.

38AUD unit also requires a separate control power

transformer for the liquid solenoid valve loads. Select

transformer part number according to unit power supply.

Unit Power Transformer Part #

208/230 HT01BD202

460 HT01BD702

575 HT01BD902

Mount the SVR (and transformer TRAN3 when used) in

unit control box. Connect per wiring schematic label on

unit or per Fig. 29 (38AUZ) or Fig. 30 (38AUD).

Capacity Control Liquid Line Solenoid Valve:

Evaporator capacity staging control via direct thermostat

control of a liquid solenoid valve on the evaporator’s

second stage circuit is not possible with 38AU models. If

this installation is a retrofit for a unit that included

automatic pressure--operated unloading, check the existing

thermostat and liquid solenoid valve wiring for possible

direct thermostat control of a solenoid valve; re--wire per

Figs. 17 or 18 and 29 or 30.

Selecting an Accumulator –

Because all 38AU models use scroll compressors, an

accumulator is not required. If an accumulator is to be

added, check the accumulator manufacturer’s literature

carefully for indication of its suitability for use with

R--410A; look for minimum working pressure of 200 psig

(1380 kPa). Select the accumulator first on the basis of its

cataloged minimum capacity (tons) to ensure oil return from

the accumulator, then on tube size or holding capacity.

Make Piping Connections —

Piping connections at the 38AU unit are ball valves with

stub tube extensions. Do not open the unit service valves

until all interconnecting tube brazing has been completed.

38AU

The stub tube connections include 1/4-in SAE service

fittings with Schrader valve cores (see Fig. 10). Before

making any brazed connections to the unit service valves,

remove both Schrader valve caps and cores and save for

re-installation. Connect a source for nitrogen to one of

these service fittings during tube brazing to prevent the

formation of copper oxides inside the tubes at brazed

joints.

Factory

High-Flow

ccess Port

Service Valve

with Stem Cap

Field Service

Access Port

(Schrader core)

Sweat

Connection

C10203

Fig. 10 -- Typical Piping Connection Assembly

When connecting the field tubing to the 38AU service

valves, wrap the valves in wet rags to prevent overheating

Pressure-test all joints from outdoor unit connections over

to the evaporator coil, using nitrogen as pressure and with

soap-and-bubbles.

When pressure-testing is completed, remove the nitrogen

source at the outdoor unit service valves and re-install the

two Schrader valve cores. Torque the cores to 2-3 in-lbs

(23-34 N-cm).

Evacuation/Dehydration —

Evacuate and dehydrate the connected refrigeration

system(s) (excluding the 38AU unit) to 500 microns using

a two-stage vacuum pump attached to the service ports

outside the 38AU service valves, following description in

GTAC II, Module 4, System Dehydration.

UNIT OPERATION AND SAFETY HAZARD

Failure to follow this warning could cause personal

injury, death and/or equipment damage.

PuronR(R--410A) refrigerant systems operate at

higher pressure than standard R--22 systems. Do not

use R--22 service equipment or components on Puron

refrigerant equipment.

!WARNING

This unit is designed for use with Puron (R--410A)

refrigerant. Do not use any other refrigerant in this

system.

Puron (R--410A) refrigerant is provided in pink (rose)

colored cylinders. These cylinders are available with and

without dip tubes; cylinders with dip tubes will have a

label indicating this feature. For a cylinder with a dip

tube, place the cylinder in the upright position (access

valve at the top) when removing liquid refrigerant for

charging. For a cylinder without a dip tube, invert the

cylinder (access valve on the bottom) when removing

liquid refrigerant.

Because Puron (R--410A) refrigerant is a blend, it is

strongly recommended that refrigerant always be removed

from the cylinder as a liquid. Admit liquid refrigerant into

the system in the discharge line. If adding refrigerant into

the suction line, use a commercial metering/expansion

device at the gauge manifold; remove liquid from the

cylinder, pass it through the metering device at the gauge

set and then pass it into the suction line as a vapor. Do not

remove Puron (R–410A) refrigerant from the cylinder as a

vapor.

Preliminary Charge —

Before starting the unit, charge R-410A liquid refrigerant

into the high side of each 38AU circuit through the liquid

service valve(s). The amount of refrigerant added must be

at least 80% of the operating charge listed in Tables 5 or 6

for LINEAR line length LESS the factory charge quantity

(if factory shipping charge has not been removed). See

example below.

Allow high and low side pressures to equalize. If pressures

do not equalize readily, charge R-410A vapor (using spe-

cial service manifold with expansion device) into the suc-

tion line service port for the low side of system to assure

charge in the evaporator. Refer to GTAC II, Module 5,

Charging, Recover, Recycling, and Reclamation for liquid

charging procedures.

Example:

38AUD*25 (RTPF)

60-ft (18.3 m) linear line length

Equivalent line length 90-ft (27.4 m)

Liquid Lift: 20-ft (6.1 m)

Select line sizes from Table 6 (38AUD):

Liquid 1/2in

Suction 1-1/8in.

Charge

Circuit 1: 23.0 lbs (at 75-ft linear length)

Circuit 2: 22.0 lbs

80% of Operating Charge:

Circuit 1: 0.80 x 23.0 = 18.4 lbs

Circuit 2: 0.80 x 22.0 = 17.6 lbs

Factory Shipping Charge: 15 lbs

Field-Charge

Circuit 1: 18.4 -- 15 = 3.4 lbs

Circuit 2: 17.6 -- 15 = 2.6 lbs

For linear line lengths longer than 125 ft (38 m), contact

your local Carrier representative for system charge value.

Step 6 — Install Accessories

Accessories requiring modifications to unit wiring should

be completed now. These accessories may include Winter

Start controls and Low Ambient controls. Refer to the

instructions shipped with the accessory.

38AU

Step 7 — Complete Electrical Connections

ELECTRICAL SHOCK HAZARD

Failure to follow this warning could result in personal

injury or death.

Do not use gas piping as an electrical ground. Unit

cabinet must have an uninterrupted, unbroken electrical

ground to minimize the possibility of personal injury if

an electrical fault should occur. This ground may consist

of electrical wire connected to unit ground lug in control

compartment, or conduit approved for electrical ground

when installed in accordance with NEC (National

Electrical Code); ANSI/NFPA 70, latest edition (in

Canada, Canadian Electrical Code CSA [Canadian

Standards Association] C22.1), and local electrical

codes.

!WARNING

NOTE: Check all factory and field electrical connections

for tightness. Field-supplied wiring shall conform with the

limitations of 63°F(33°C) rise.

Field Power Supply —

If equipped with optional Powered Convenience Outlet:

The power source leads to the convenience outlet’s

transformer primary are not factory connected. Installer

must connect these leads according to required operation

of the convenience outlet. If an always-energized

convenience outlet operation is desired, connect the

source leads to the line side of the unit-mounted

disconnect. (Check with local codes to ensure this method

is acceptable in your area.) If a de-energize via unit

disconnect switch operation of the convenience outlet is

desired, connect the source leads to the load side of the

unit disconnect. On a unit without a unit-mounted

disconnect, connect the source leads to compressor

contactor C and indoor fan contactor IFC pressure lugs

with unit field power leads..

Field power wires are connected to the unit at line-side

pressure lugs on compressor contactor C and TB1 (see

wiring diagram label for control box component

arrangement) or at factory-installed option non-fused

disconnect switch. Max wire size is #4 AWG (copper

only).

NOTE: TEST LEADS - Unit may be equipped with short

leads (pigtails) on the field line connection points on

contactor C or optional disconnect switch. These leads are

for factory run-test purposes only; remove and discard

before connecting field power wires to unit connection

points. Make field power connections directly to line

connection pressure lugs only.

FIRE HAZARD

Failure to follow this warning could cause in personal

injury, death and/or equipment damage.

Do not connect aluminum wire between disconnect

switch and condensing unit. Use only copper wire.

(See Fig. 11.)

!WARNING

COPPER

WIRE ONLY

ELECTRIC

DISCONNECT

SWITCH

ALUMINUM

WIRE

A93033

Fig. 11 -- Disconnect Switch and Unit

Units Without Factory-Installed Disconnect —

When installing units, provide a disconnect switch per

NEC (National Electrical Code) of adequate size.

Disconnect sizing data is provided on the unit informative

plate. Locate on unit cabinet or within sight of the unit per

national or local codes. Do not cover unit informative

plate if mounting the disconnect on the unit cabinet.

Units with Factory-Installed Disconnect —

The factory-installed option disconnect switch is located

in a weatherproof enclosure located under the main

control box. The manual switch handle is accessible

through an opening in the access panel.

All Units —

All field wiring must comply with NEC and all local

codes. Size wire based on MCA (Minimum Circuit Amps)

on the unit informative plate. See Fig. 12 for power wiring

connections to the unit contactor and terminal block and

equipment ground.

Provide a ground-fault and short-circuit over-current

protection device (fuse or breaker) per NEC Article 440

(or local codes). Refer to unit informative data plate for

MOCP (Maximum Over-current Protection) device size.

All units except 208/230-v units are factory wired for the

voltage shown on the nameplate. If the 208/230-v unit is

to be connected to a 208-v power supply, the control

transformer must be rewired by moving the black wire

with the

1/4

-in. female spade connector from the 230-v

connection and moving it to the 208-v

1/4

-in. male

terminal on the primary side of the transformer. Refer to

unit label diagram for line-side information.

38AU

11 13

L1 L2 L3

CTB1

208/230-3-60

460-3-60

575-3-60

Units Without Disconnect Option

Units With Disconnect Option

Optional

Disconnect

Switch

Disconnect factory test leads; discard.

Factory

Wiring

Disconnect

per

NEC

C10204

Fig. 12 -- Power Wiring Connections

Affix the crankcase heater warning sticker to the unit

disconnect switch.

Convenience Outlets —

ELECTRICAL OPERATION HAZARD

Failure to follow this warning could result in personal

injury or death.

Units with convenience outlet circuits may use

multiple disconnects. Check convenience outlet for

power status before opening unit for service. Locate

its disconnect switch, if appropriate, and open it.

Tag-out this switch, if necessary.

!WARNING

Two types of convenience outlets are offered on 38AU

models: Non-powered and unit-powered. Both types

provide a 125-volt GFCI (ground-fault circuit-interrupter)

duplex receptacle rated at 15-A behind a hinged

waterproof access cover, located on the end panel of the

unit. See Fig. 13.

Non-powered type: This type requires the field

installation of a general-purpose 125-volt 15-A circuit

powered from a source elsewhere in the building. Observe

national and local codes when selecting wire size, fuse or

breaker requirements and disconnect switch size and

location. Route 125-v power supply conductors into the

bottom of the utility box containing the duplex receptacle.

Unit-powered type: A unit-mounted transformer is

factory-installed to stepdown the main power supply voltage

to the unit to 115-v at the duplex receptacle. This option also

includes a manual switch with fuse, located in a utility box

and mounted on a bracket behind the convenience outlet;

access is through the unit’s control box access panel. See

Fig. 13.

Control Box

Access Panel

Pwd-CO

Transformer

Convenience

Outlet

GFCI

Pwd-CO

Fuse

Switch

C10205

Fig. 13 -- Convenience Outlet Location

The primary leads to the convenience outlet transformer are

not factory-connected. Selection of primary power source is

a customer-option. If local codes permit, the transformer

primary leads can be connected at the line-side terminals on

the unit-mounted non-fused disconnect switch; this will

provide service power to the unit when the unit disconnect

switch is open. Other connection methods will result in the

convenience outlet circuit being de-energized when the unit

disconnect is open. See Fig. 14.

C10206

UNIT

VOLTAGE

CONNECT

PRIMARY

CONNECTIONS

TRANSFORMER

TERMINALS

208,

230 240

L1: RED + YEL

L2: BLU + GRA

H1 + H3

H2 + H4

460 480

L1: RED

Splice BLU +

YEL

L2: GRA

H2 + H3

575 600 L1: RED

L2: GRA

Fig. 14 -- Powered Convenience Outlet Wiring

The unit-powered convenience outlet has a 1000 VA rated

transformer. Maximum continuous current must not

exceed 8 Amps.

38AU

B50HJ542739

Maximum Continuous use : 8 Amps 24/7

Convenience Outlet Utilization

NOTICE

C10207

Fig. 15 -- Convenience Outlet Utilization Notice Label

Test the GFCI receptacle by pressing the TEST button on

the face of the receptacle to trip and open the receptacle.

Check for proper grounding wires and power line phasing

if the GFCI receptacle does not trip as required. Press the

RESET button to clear the tripped condition.

Fuse on power type: The factory fuse is a Bussman

“Fusetron” T-15, non-renewable screw-in (Edison base)

type plug fuse.

ELECTRICAL OPERATION HAZARD

Failure to follow this warning could result in personal

injury or death.

Using unit-mounted convenience outlets: Units with

unit-mounded convenience outlet circuits will often

require that two disconnects be opened to de-energize

all power to the unit. Treat all units as electrically

energized until the convenience outlet power is also

checked and de-energization is confirmed. Observe

National Electrical Code Article 210, Branch Circuits,

for use of convenience outlets.

!WARNING

Installing Weatherproof Cover: A weatherproof while in

use cover for the factory installed convenience outlets is

now required by UL standards. This cover cannot be

factory mounted due its depth; it must be installed at unit

installation. For shipment, the convenience outlet is

covered with a blank cover plate.

The weatherproof cover kit is shipped in the unit’s control

box. The kit includes the hinged cover, a backing plate

and gasket.

DISCONNECT ALL POWER TO UNIT AND

CONVENIENCE OUTLET.

Remove the blank cover plate at the convenience outlet;

discard the blank cover.

Loosen the two screws at the GFCI duplex outlet, until

approximately 1/2--in (13 mm) under screw heads are

exposed. Press the gasket over the screw heads. Slip the

backing plate over the screw heads at the keyhole slots

and align with the gasket; tighten the two screws until

snug (do not overtighten).

Mount the weatherproof cover to the backing plate as

shown in Fig. 16. Remove two slot fillers in the bottom of

the cover to permit service tool cords to exit the cover.

Check for full closing and latching.

C09022

Fig. 16 -- Weatherproof Cover Installation

All Units —

Voltage to compressor terminals during operation must be

within voltage range indicated on unit nameplate. See

Tables 10 and 11. On 3-phase units, voltages between

phases must be balanced within 2% and the current within

10%. Use the formula shown in the legend for Tables 10

and 11, Note 5 (see page 22) to determine the percent of

voltage imbalance. Operation on improper line voltage or

excessive phase imbalance constitutes abuse and may

cause damage to electrical components. Such operation

would invalidate any applicable Carrier warranty.

Field Control Wiring —

38AU unit control voltage is 24 v. See Fig. 29 (38AUZ)

and Fig. 30 (38AUD) for typical field control connections

and the unit’s label diagram for field-supplied wiring

details. Route control wires to the 38AU unit through the

opening in unit’s end panel to the connections terminal

board in the unit’s control box.

Remainder of the system controls connection will vary

according to the specific construction details of the indoor

section (air handler or packaged fan coil). Fig. 17

(38AUZ) and Fig. 18 (38AUD) depict typical connections

to a Carrier 40RU fan coil unit. Plan for field connections

carefully and install control wiring correctly per the

project plan. Additional components and supplemental

transformer accessory may be required.

The 38AU unit requires an external temperature control

device. This device can be a thermostat (field-supplied) or

a PremierLink controller (available as a field-installed

accessory, for use on a Carrier Comfort Network or as a

stand alone control).

38AU

Thermostat —

Install a Carrier-approved accessory thermostat according

to installation instructions included with the accessory.

Locate the thermostat accessory on a solid wall in the

conditioned space to sense average temperature in

accordance with the thermostat installation instructions.

The 38AUZ is a single-circuit, two--stage cooling unit.

Select a two—stage cooling thermostat, with or without

supplemental heating as needed.

The 38AUD is a dual--circuit, two-stage cooling unit.

Select a two—stage cooling thermostat, with or without

supplemental heating as needed.

Select a thermostat cable or equivalent single leads of

different colors with minimum of five leads for 38AUZ or

six leads for 38AUD unit. Check the thermostat

installation instructions for additional features which

might require additional conductors in the cable.

For wire runs up to 50 ft. (15 m), use no. 18 AWG

(American Wire Gage) insulated wire (35C minimum).

For50to75ft.(15to23m),useno.16AWGinsulated

wire (35C minimum). For over 75 ft. (23 m), use no. 14

AWG insulated wire (35C minimum). All wire sizes

larger than no. 18 AWG cannot be directly connected to

the thermostat and will require a junction box and splice

at the thermostat.

PremierLink (accessory installation) – Refer to Form

33CS-58SI for details on connecting the PremierLink

controller and its various sensors.

Note 1: Typical multi-function marking. Follow manufacturer’s configuration

instructions to select Y2.

Note 2: Connect only if thermostat requires 24-vac power source.

Note 3: Connect W1 and W2 if supplemental heaters are installed

Field Wiring

(Note 1)

(Note 2)

(Note 3)

C10208

Fig. 17 -- Typical Remote Thermostat Connections

— 38AUZ

Note 1: Typical multi-function marking. Follow manufacturer’s configuration

instructions to select Y2.

Note 2: Connect only if thermostat requires 24-vac power source.

Note 3: Connect W1 and W2 if supplemental heaters are installed

Field Wiring

(Note 1)

(Note 2)

(Note 3)

C10078

Fig. 18 -- Typical Remote Thermostat Connections

— 38AUD

Control Circuit Wiring —

Control voltage is 24 v. See Fig. 12 and the unit’s label

diagram for field--supplied wiring details. Route control

wires through the opening in unit’s end panel to the

connection in the unit’s control box.

Control Transformer Wiring —

On multi voltage units, check the transformer primary

wiring connections. See Fig. 19 or refer to the unit’s label

diagram.

If the unit will be operating at 208-3-60 power, remove

the black wire (BLK) from the transformer primary

connection labelled “230” and move it to the connection

labelled “208”. See Fig. 19.

C10079

Fig. 19 -- Control Transformer Wiring

38AU

Table 10 – Unit Wire/Fuse or HACR Breaker Sizing Data

UNIT

SIZE

38AU

NOMINAL

POWER

SUPPLY

VOLTAGE

RANGE

COMPRESSOR NO C.O. or UNPWRD C.O.

No. 1 No. 2 OFM POWER SUPPLY DISCONNECT SIZE

V --- P h --- H z Min Max RLA LRA RLA LRA Qty FLA

(ea) MCA

FUSE or

HACR

BRKR

FLA LRA

D*16

Z*16

208/230---3 ---60 187 253 25.0 164 25.0 164 31.5 60.8/60.8 80/80 63/63 337/337

4 6 0 --- 3 --- 6 0 414 506 12.2 100 12.2 100 30.8 29.9 40 31 206

5 7 5 --- 3 --- 6 0 518 633 9.0 78 9.0 78 30.7 22.4 30 23 162

D*25

Z*25

208/230---3 ---60 187 253 30.1 225 30.1 225 41.5 73.7/73.7 100/100 76/76 462/462

4 6 0 --- 3 --- 6 0 414 506 16.7 114 16.7 114 40.8 40.8 50 42 236

5 7 5 --- 3 --- 6 0 518 633 12.2 80 12.2 80 40.7 30.3 40 31 168

UNIT

SIZE

38AU

NOMINAL

POWER

SUPPLY

VOLTAGE

RANGE

COMPRESSOR w/ PWRD C.O.

No. 1 No. 2 OFM POWER SUPPLY DISCONNECT SIZE

V --- P h --- H z Min Max RLA LRA RLA LRA Qty FLA

(ea) MCA

FUSE or

HACR

BRKR

FLA LRA

D*16

Z*16

208/230---3 ---60 187 253 25.0 164 25.0 164 31.5 65.6/65.6 90/90 68/68 342/342

4 6 0 --- 3 --- 6 0 414 506 12.2 100 12.2 100 30.8 32.1 40 33 208

5 7 5 --- 3 --- 6 0 518 633 9.0 78 9.0 78 30.7 24.1 30 25 164

D*25

Z*25

208/230---3 ---60 187 253 30.1 225 30.1 225 41.5 78.5/78.5 100/100 82/82 467/467

4 6 0 --- 3 --- 6 0 414 506 16.7 114 16.7 114 40.8 43 50 45 238

5 7 5 --- 3 --- 6 0 518 633 12.2 80 12.2 80 40.7 32 40 33 170

Legend and Notes for Table 10

LEGEND:

BRKR --- Circuit breaker

CO --- Convenient outlet

F L A --- Fu l l L o a d A m p s

LRA --- Locked Rotor Amps

MCA --- Minimum Circuit Amps

Protection

NEC --- National Electrical Code

PWRD CO --- Powered convenient outlet

RLA --- Rated Load Amps

UNPWR CO --- Unpowered convenient outlet

NOTES:

1. In compliance with NEC requirements for multimotor and

combination load equipment (refer to NEC Articles 430 and

440), the overcurrent protective device for the unit shall be

fuse or HACR breaker. Canadian units may be fuse or circuit

breaker.

2. The MCA values are calculated in accordance with The NEC.

Article 440.

3. Motor RLA and LRA values are established in accordance

with Underwriters’ Laboratories (UL). Standard 1995.

4 . T h e 5 7 5 --- v u n i t s a r e U L , C a n a d a --- l i s t e d o n l y.

5. Unbalanced 3-Phase Supply Voltage

Never operate a motor where a phase imbalance in supply

voltage is greater than 2%. Use the following formula to de-

termine the percentage of voltage imbalance.

Example: Supply voltage is 230-3-60

% Voltage Imbalance = 100 x

max voltage deviation from average voltage

average voltage

AB = 224 v

BC = 231 v

AC = 226 v

Average Voltage =

(224 + 231 + 226)

681

= 227

Determine maximum deviation from average voltage.

(AB) 227 – 224 = 3 v

(BC) 231 – 227 = 4 v

(AC) 227 – 226 = 1 v

Maximum deviation is 4 v.

Determine percent of voltage imbalance.

% Voltage Imbalance = 100 x

227

= 1.76%

This amount of phase imbalance is satisfactory as it is below the

maximum allowable 2%.

IMPORTANT: If the supply voltage phase imbalance is more than

2%, contact your local electric utility company immediately.

38AU

PRE-START-UP

IMPORTANT: Before beginning Pre-Start-Up or

Start-Up, review Start-Up Checklist at the back of this

book. The Checklist assures proper start-up of a unit

and provides a record of unit condition, application

requirements, system information, and operation at

initial start-up.

UNIT DAMAGE HAZARD

Failure to follow this caution may result in equipment

damage.

Do not attempt to start the condensing unit, even

momentarily, until the following steps have been

completed. Compressor damage may result.

CAUTION

System Check

1. The electrical power source must agree with the unit’s

nameplate rating.

2. Check all air handler(s) and other equipment auxiliary

components. Consult the manufacturer’s instructions re-

garding any other equipment connected to the condens-

ing unit. If the unit has field-installed accessories, be

sure all are properly installed and correctly wired. If

used, the airflow switch must be properly installed.

3. Check tightness of all electrical connections.

4. Be sure liquid line and low side of the system are

properly leak checked and dehydrated.

5. Be sure the unit is properly charged. See “Preliminary

Charge”, below.

6. Open the liquid line and suction line service valves.

7. The crankcase heater must be firmly attached to the

compressor crankcase. Be sure the crankcase is warm

(heater must be on for 24 hours before starting com-

pressor).

Turn On Crankcase Heater —

Turn on the crankcase heater for 24 hours before starting

the unit to be sure all the refrigerant is out of the oil.To

energize the crankcase heater, proceed as follows:

1. Set the space thermostat set point above the space

temperature so there is no demand for cooling.

2. Close the field disconnect.

Preliminary Charge —

Before starting the unit, charge liquid refrigerant into the

high side of the system through the liquid service valve. The

amount of refrigerant added must be at least 80% of the

operating charge listed in the Physical Data table (Tables 1A

through 2B, pages 6 through 9). Allow high and low side

pressures to equalize before starting compressor. If pressures

do not equalize readily, charge vapor on low side of system

to assure charge in the evaporator. Refer to GTAC II,

Module 5, Charging, Recover, Recycling, and Reclamation

for liquid charging procedures.

UNIT DAMAGE HAZARD

Failure to follow this caution may result in equipment

damage.

Prior to starting compressor, a preliminary charge of

refrigerant must be added to avoid possible

compressor damage.

CAUTION

START-UP

38AU Units: The compressor crankcase heater must be on

for 24 hours before start-up. After the heater has been on

for 24 hours, the unit can be started. If no time elapsed

since the preliminary charge step was completed, it is

unnecessary to wait the 24-hour period.

Preliminary Checks

1. Check that electric power supply agrees with unit

nameplate data.

2. Verify that the compressor crankcase heater is se-

curely in place.

3. Check that the compressor crankcase heater has been

on at least 24 hours.

4. Recheck for leaks using the procedure outlined in the

Pre-Start-Up section, Leak Test and Dehydration. If

any leaks are detected, repair as required. Evacuate

and dehydrate as described in the Leak Test and De-

hydration section.

5. Ensure that the preliminary charge has been added as

described in the Pre-Start-Up section, Preliminary

Charge.

6. All internal wiring connections must be tight, and all

barriers and covers must be in place.

NOTE: The 38AU units are factory charged with the

required amount of oil. If recharging in required, use

Emkarate RL 32-3MAF for the 38AU units.

Compressor Rotation —

On 3--phase units with scroll compressors, it is important to

be certain that the compressor is rotating in the proper

direction. 38AU units are equipped with a Comfort Alert

Diagnostic Module (CADM). Alert Code 7 indicates reverse

power phasing.

To correct phase order:

1. Turn off power to the unit, tag disconnect.

2. Reverse any two of the unit power leads.

3. Reapply power to the compressor, verify correct pres-

sures.

To verify the compressor is rotating in the proper

direction:

1. Connect service gages to the suction and liquid pres-

sure fittings.

2. Energize the compressor.

3. The suction pressure should drop and the liquid pres-

sure should rise, as is normal on any start--up.

38AU

Compressor Overload —

This overload interrupts power to the compressor when

either the current or internal motor winding temperature

becomes excessive, and automatically resets when the

internal temperature drops to a safe level. This overload

may require up to 60 minutes (or longer) to reset. If the

internal overload is suspected of being open, disconnect

the electrical power to the unit and check the circuit

through the overload with an ohmmeter or continuity

tester.

Advanced Scroll Temperature Protection (ASTP) —

A label located above the terminal box identifies Copeland

Scroll compressor models that contain this technology. See

Fig. 20. Advanced Scroll Temperature Protection (ASTP) is

a form of internal discharge temperature protection, that

unloads the scroll compressor when the internal temperature

reaches approximately 149_C (300_F). At this temperature,

an internal bi--metal disk valve opens and causes the scroll

elements to separate, which stops compression. Suction and

discharge pressures balance while the motor continues to

run. The longer the compressor runs unloaded, the longer it

must cool before the bi--metal disk resets. See Fig. 21.

C10080

Fig. 20 -- Advanced Scroll Temperature Protection Label

100

110

120

0 10203040 6070809050

Compressor Unloaded Run Time (Minutes)*

*Times are approximate.

NOTE: Various factors, including high humidity, high ambient

temperature, and the presence of a sound blanket will

increase cool-down times.

Recommended Cooling Time*

(Minutes)

C10081

Fig. 21 -- Recommended Minimum Cool-Down Time

After Compressor is Stopped

To manually reset ASTP, the compressor should be

stopped and allowed to cool. If the compressor is not

stopped, the motor will run until the motor protector trips,

which occurs up to 90 minutes later. Advanced Scroll

Temperature Protection will reset automatically before the

motor protector resets, which may take up to 2 hours.

Start Unit

Set the space thermostat to a set point above space

temperature so that there is no demand for cooling. Close

the 38AU disconnect switch. Only the crankcase heater

will be energized.

Reset the space thermostat below ambient so that a call

for cooling is ensured.

UNIT DAMAGE HAZARD

Failure to follow this caution may result in equipment

damage.

Never charge liquid into the low-pressure side of

system. Do not overcharge. During charging or

removal of refrigerant, be sure indoor-fan system is

operating. Ensure both outdoor fan motors are

running; bypass any Motormaster function.

CAUTION

Adjust Refrigerant Charge —

Refer to Cooling Charging Charts, Fig. 23 through Fig. 28.

For applications with line lengths greater than 125 ft (38 m),

contact Carrier representative. Vary refrigerant until the

conditions of the chart are met. Note that the charging charts

are different from the type normally used. The charts are

based on charging the units to the correct subcooling for the

various operating conditions. Accurate pressure gage and

temperature sensing device are required. Connect the

pressure gage to the service port on the liquid line service

valve. Mount the temperature sensing device on the liquid

line close to the liquid line service valve, and insulate it so

that outdoor ambient temperature does not affect the reading.

Indoor airflow must be within the unit’s normal operating

range. Operate the unit for a minimum of 15 minutes.

Ensure that pressure and temperature readings have

stabilized. Plot the liquid pressure and temperature on chart

and add or reduce the charge to meet the curve. Adjust the

charge to conform with the charging chart, using the liquid

pressure and temperature to read the chart.

Using plotted operating point:

If plotted operating condition is -- Adjust charge by --

BELOW the curve REDUCE charge

ABOVE the curve ADD charge

38AU

38AUZ*25 Check Compressor Oil Level —

After adjusting the refrigerant charge, allow the unit to

run fully loaded for 20 minutes. Stop the compressors and

check the oil level. Oil level should be 1/3to 1/2up on the

sight glass (see Fig. 22).

1/3 (MIN)

1/2 (MAX)

C01377

Fig. 22 -- Recommended Oil Level — 38AUZ*25

IMPORTANT: Oil level should only be checked

when the compressors are off.

Add oil only if necessary to bring the oil into view in the

sight glass. If oil is added, run the circuit for an additional

10 minutes, then stop and check oil level. If the level

remains low, check the piping system for proper design

for oil return; also, check the system for leaks. If checking

the oil level with unit running in part load, let unit run one

hour, then run at full load for 10 minutes. If oil does not

return to acceptable sight glass levels, check for correct

suction piping and line sizing.

Final Checks —

Ensure that all safety controls are operating, control panel

covers are on, and the service panels are in place.

C10945

Fig. 23 -- 38AUZ*16 Charging Chart (Novation)

38AU

(CIRCUIT 1)

(CIRCUIT 2)

C10946

Fig. 24 -- 38AUD*16 Charging Chart (Novation)

38AU

C10947

Fig. 25 -- 38AUZ*16 Charging Chart (RTPF)

C10948

Fig. 26 -- 38AUZ*25 Charging Chart (RTPF)

38AU

C10949

Fig. 27 -- 38AUD*16 Charging Chart (RTPF)

38AU

(CIRCUIT 1)

(CIRCUIT 2)

C10950

Fig. 28 -- 38AUD*25 Charging Chart (RTPF)

38AU

C10212A

Fig. 29 -- Typical 38AUZ Wiring Diagram - (15 Ton 230V Tandem Unit Shown)

38AU

C10213A

Fig. 30 -- Typical 38AUD Wiring Diagram - (15 Ton 230V Dual Unit Shown)

38AU

OPERATING SEQUENCE

Base Unit Controls

Indoor (Supply) Fan —

The indoor fan contactor (IFC) is remotely located at the fan

coil or fan section. If the thermostat fan operation is selected

as Continuous, the IFC is energized and the indoor (supply)

fan motor runs continuously. If the thermostat fan operation

is selected as Automatic, the IFC will be energized on a call

for Cooling; indoor (supply) fan motor runs. When

thermostat call for Cooling is satisfied, the IFC is

de-energized and indoor (supply) fan motor stops.

Cooling, Unit Without Economizer —

38AUZ (Single Circuit)

On a thermostat call for Cooling, IFC will be energized

and indoor (supply) fan motor runs. Thermostat output Y1

is energized; terminal Y1 at 38AUZ unit receives 24-v.

24-v received at CADM1 terminal Y. If anti-recycle time

delay period has not expired, CADM1 relay will remain

open, de-energizing Solenoid Valve Relay (SVR) and

preventing compressor start. When safety pressure

switches are closed and CADM1 time delay expires,

CADM1 relay closes, SVR and compressor contactor C1

are energized; liquid line solenoid valve LLSV opens, all

outdoor fan motors start and Compressor 1 starts.

On a thermostat calling for Stage 2 Cooling, thermostat

output Y2 is energized; terminal Y2 at 38AUZ unit

receives 24-v. 24-v received at CADM2 terminal Y. If

anti-recycle time delay period has not expired, CADM2

relay will remain open, preventing Compressor 2 start.

When safety pressure switches are closed and CADM2

time delay expires, CADM2 relay closes, compressor

contactor C2 is energized; Compressor 2 starts.

As space cooling load is satisfied, thermostat outputs Y2

and Y1 are de--energized, removing 24-v at 38AUZ

terminals Y2 and Y1. Compressor 2 stops on Y2 opening.

CADM2 begins its three-minute anti-recycle time delay.

On Y1 opening, Compressor 1 stops, all outdoor fan

motors stop and SVR relay is de-energized. Liquid line

solenoid valve is de-energized and valve closes. CADM1

begins its three-minute anti-recycle time delay.

38AUD (Two Circuit)

On a thermostat call for Cooling, IFC will be energized

and indoor (supply) fan motor runs. Thermostat output Y1

is energized; terminal Y1 at 38AUD unit receives 24-v.

24-v received at CADM1 terminal Y. If anti-recycle time

delay period has not expired, CADM1 relay will remain

open, de-energizing Solenoid Valve Relay 1 (SVR1) and

preventing compressor start. When safety pressure

switches are closed and CADM1 time delay expires,

CADM1 relay closes, SVR1 and compressor contactor C1

are energized; liquid line solenoid valve LLSV1 opens, all

outdoor fan motors start and Circuit 1 compressor starts.

On a thermostat calling for Stage 2 Cooling, thermostat

output Y2 is energized; terminal Y2 at 38AUD unit

receives 24-v. 24-v received at CADM2 terminal Y. If

anti-recycle time delay period has not expired, CADM2

relay will remain open, de-energizing Solenoid Valve

Relay 2 (SVR2) and preventing compressor start. When

safety pressure switches are closed and CADM2 time

delay expires, CADM2 relay closes, SVR2 and

compressor contactor C2 are energized; liquid line

solenoid valve LLSV2 opens and Circuit 2 compressor

starts.

As space cooling load is satisfied, thermostat outputs Y2

and Y1 are de--energized, removing 24-v at 38AUD

terminals Y2 and Y1. Circuit 2 compressor stops on Y2

opening; SVR2 is de-energized and LLSV2 closes.

CADM2 begins its three-minute anti-recycle time delay.

On Y1 opening, Circuit 1 compressor stops, all outdoor

fan motors stop and SVR1 relay is de-energized. Liquid

line solenoid valve LLSV1 is de-energized and valve

closes. CADM1 begins its three-minute anti-recycle time

delay.

All Units

If either the Low Pressure Switch or High Pressure Switch

opens while thermostat output Y1 or Y2 remain energized,

the compressor contactor is de-energized, the compressor

stops and liquid line solenoid is de-energized (valve

closes). CADM initiates a TRIP event (cooling demand

sensed at CADM terminal Y but no current is measured at

T1, T2, T3 motor sensors); CADM relay opens and RED

LED is illuminated. TRIP condition maintains lockout of

compressor operation until CADM is manually reset.

Reset CADM by cycling unit main power.

Complete system shutdown may be caused by loss of

main power, open compressor internal overload, open

low-pressure or high-pressure switch, or a fault detected

by the CADM logic. Compressor operation without

cooling may indicate the compressor’s ASTP feature is

active; disconnect unit power and allow compressor to

cool. See Service section for further details.

Cooling, Unit With Economizer —

Refer to fan coil unit installation instructions and

economizer accessory installation instructions for

operating sequences when system is equipped with

accessory economizer.

Heating —

Refer to fan coil unit installation instructions and accessory

heating device installation instructions for operating

sequences in heating mode.

38AU

ROUTINE SYSTEM MAINTENANCE

These items should be part of a routine maintenance

program, to be checked every month or two, until a specific

schedule for each can be identified for this installation:

Quarterly Inspection (and 30 days after initial start) —

Indoor section

SCondenser coil cleanliness checked.

SReturn air filter replacement

SOutdoor hood inlet filters cleaned

SBelt tension checked

SBelt condition checked

SPulley alignment checked

SFan shaft bearing locking collar tightness checked

SCondensate drain checked

Seasonal Maintenance —

These items should be checked at the beginning of each

season (or more often if local conditions and usage patterns

dictate):

Air Conditioning

SCondenser fan motor mounting bolts tightness

SCompressor mounting bolts

SCondenser fan blade positioning

SControl box cleanliness and wiring condition

SWire terminal tightness

SRefrigerant charge level

SEvaporator coil cleaning

SEvaporator blower motor amperage

Heating

SPower wire connections

SFuses ready

SManual-reset limit switch is closed

Economizer or Outside Air Damper

SInlet filters condition

SCheck damper travel (economizer)

SCheck gear and dampers for debris and dirt

SERVICE

Refrigeration System

EQUIPMENT DAMAGE HAZARD

Failure to follow this caution may result in damage to

equipment.

This system uses PuronRrefrigerant which has higher

pressures than R-22 and other refrigerants. No other

refrigerant may be used in this system. Gage set,

hoses, and recovery system must be designed to

handle Puron. If you are unsure consult the equipment

manufacturer.

CAUTION

Compressor Oil —

EQUIPMENT DAMAGE HAZARD

Failure to follow this caution may result in damage to

equipment.

The compressor in a Puron system uses a polyolester

(POE) oil. This oil is extremely hygroscopic, meaning

it absorbs water readily. POE oils can absorb 15 times

as much water as other oils designed for HCFC and

CFC refrigerants. Take all necessary precautions to

avoid exposure of the oil to the atmosphere.

CAUTION

Servicing Systems on Roofs With Synthetic Materials —

POE (polyolester) compressor lubricants are known to cause

long term damage to some synthetic roofing materials.

Exposure, even if immediately cleaned up, may cause

embrittlement (leading to cracking) to occur in one year or

more. When performing any service which may risk

exposure of compressor oil to the roof, take appropriate

precautions to protect roofing. Procedures which risk oil

leakage include but are not limited to compressor

replacement, repairing refrigerants leaks, replacing

refrigerant components such as filter drier, pressure switch,

metering device, coil, accumulator, or reversing valve.

Synthetic Roof Precautionary Procedure:

1. Cover extended roof working area with an imper-

meable polyethylene (plastic) drop cloth or tarp.

Cover an approximate 10 x 10 ft (3.3 x 3.3 m) area.

2. Cover area in front of the unit service panel with a

terry cloth shop towel to absorb lubricant spills and

prevent run-offs, and protect drop cloth from tears

caused by tools or components.

3. Place terry cloth shop towel inside unit immediately un-

der component(s) to be serviced and prevent lubricant

run-offs through the louvered openings in the base pan.

4. Perform required service.

5. Remove and dispose of any oil contaminated material

per local codes.

38AU

Liquid Line Filter Drier —

The factory-provided filter drier is specifically designed to

operate with Puron®. Replace the filter drier with

factory-authorized components only with a filter drier

with desiccant made from 100% molecular sieve grade

XH-11. Filter drier must be replaced whenever the

refrigerant system is opened.

When removing a filter drier, use a tubing cutter to cut the

drier from the system. Do not unsweat a filter drier from

the system. Heat from unsweating will release moisture

and contaminants from drier into system.

Field Refrigerant Access Ports —

Field service access to refrigerant pressures is through the

access ports located at the service valves (see Figs 34 and

38). These ports are 1/4-in SAE Flare couplings with

Schrader check valves and service caps. Use these ports to

admit nitrogen to the field tubing during brazing, to

evacuate the tubing and evaporator coil, to admit initial

refrigerant charge into the low-side of the system and

when checking and adjusting the system refrigerant

charge. When service activities are completed, ensure the

service caps are in place and secure; check for leaks. If

the Schrader check valve must be removed and

re-installed, tighten to 2-3 in-lbs (23-34 N-cm).

Factory High-Flow Access Ports —

There are two additional access ports in the system - on

the suction tube between the compressor and the suction

service valve and on the liquid tube near the liquid service

valve (see Figs 35 and 39). These are brass fittings with

black plastic caps. The hose connection fittings are

standard 1/4-in SAE Male Flare couplings.

The brass fittings are two-piece High Flow valves, with a

receptacle base brazed to the tubing and an integral

spring-closed check valve core screwed into the base. (See

Fig. 31) This check valve is permanently assembled into

this core body and cannot be serviced separately; replace

the entire core body if necessary. Service tools are

available from RCD that allow the replacement of the

check valve core without having to recover the entire

system refrigerant charge. Apply compressor refrigerant

oil to the check valve core’s bottom o-ring. Install the

fitting body with 96 ±-10 in-lbs (1085 ±23 N-cm) of

torque; do not overtighten.

1/2-20 UNF RH

30°

0.596

.47

5/8” HEX

SEAT CORE

WASHER DEPRESSOR PER ARI 720

+.01/-.035

FROM FACE OF BODY

7/16-20 UNF RH

O-RING

45°

1/2" HEX

This surface provides a metal to metal seal when

torqued into the seat. Appropriate handling is

required to not scratch or dent the surface.

(Part No. EC39EZ067)

C08453

Fig. 31 -- CoreMax Access Port Assembly

38AU

Comfort Alert Diagnostic Module

The Comfort Alert Diagnostic Module (CADM) monitors

and analyzes data from the Copeland Scroll®three-phase

compressor and the thermostat demand. The CADM also

provides a 3-minute anti-recycle time delay to compressor

cycling. Each compressor has a separate CADM module.

The CADM detects causes for electrical and system

related failures without any sensors. Flashing LEDs

communicate the Alert codes to guide service technicians

in accurately and quickly troubleshooting the system and

determining root cause for the failure.

Inputs to the CADM include 24-vac power, thermostat Y1

or Y2, compressor contactor coil (common side) and

compressor power leads (from the compressor contactor).

Input Te r m i n a l Voltage

Control

Power R24-V

Control

Common C24-V

Cooling Y24-V

Contactor

Coil P24-V

Line A T1 Line

Line B T2 Line

Line C T3 Line

Control of the compressor contactor coil is through a

normally-closed (power on the module) contact between

terminals P and C.

Communications of status and alert conditions is through

three LEDs located on the top edge of the module housing

(see Fig. 32): POWER (green), ALERT (yellow), and

TRIP (red).

The POWER LED indicates the presence of control power

to the CADM.

The ALERT LED indicates an abnormal condition exists

in the system through a flash code. The ALERT LED will

blink a number of times consecutively, pause and the

repeat the process. The number of blinks, defined in Table

11, correlates to a particular abnormal condition;

troubleshooting tips are provided for each Alert code.

Reset of the ALERT may be automatic or manual. If the

fault condition causing the Alert is self-corrected, the

Alert code will be removed and the CADM will

automatically reset and allow the system to restart

normally. Manual reset requires that main power to the

38AU unit be recycled after the cause for the Alert

condition has been detected and corrected.

POWER

(GRN)

ALERT

(YEL)

TRIP

(RED)

C10086

Fig. 32 -- CADM Housing/LED Locations

The TRIP LED indicates either a time-delay period is

currently active (RED LED is blinking) or the module has

locked out the compressor (RED LED is on steady). A

lockout condition will occur when the CADM detects a

thermostat demand at input Y but there is no power at the

compressor line terminals T1 or T2 or T3. This lockout

can occur due to a safety switch (LPS or HPS) opening

and de-energizing the compressor contactor, the

compressor-motor internal overload opens, or other

internal power interruption has occurred. Reset of the

TRIP LED requires that unit main power be recycled after

the loss of power to the compressor condition has been

detected and corrected.

Simultaneous Blinking of YELLOW and RED LEDs

indicates control power input to the CADM is low. Check

control circuit transformer and wiring.

Troubleshooting the CADM Wiring – Flashing LEDs also

indicate wiring problems to the CADM. See Table 12 for

discussion of additional LED flash codes and

troubleshooting instructions.

38AU

Table 11 – LED Status Codes

Status LED Status LED Description Status LED Troubleshooting Information

Green “POWER” Module has power Supply voltage is present at module terminals

Red “TRIP”

LED On Solid

Thermostat demand signal

Y is present, but the com-

pressor is not running.

1. Compressor protector is open

2. Condensing unit power disconnect is open

3. Compressorcircuitbreakerorfuse(s)isopen

4. Broken supply wires or connector is not making contact

5. Compressor power wires not routed through Comfort Alert

6. Compressor contactor has failed open

Red “TRIP” LED

Flashing

The anti-short cycle timer (3 minutes) in module is preventing compressor restart.

Module locks out compressor when compressor damaging ALERT code appears.

Lockout ALERT codes are noted in the Status LED Description.

During a compressor lock out, 24VAC power must be removed from module to manually reset.

Yellow “ALERT”

LED On Solid

A short circuit or over cur-

rent condition exists on

PROT terminal.

1. Compressor contactor coil shorted

2. Electrical load too high for PROT circuit (maximum 1 Amp)

3. 24 V AC wired directly to PROT terminal

Yellow “ALERT”

Flash Code 2

System Pressure Trip

Discharge pressure out of

limits or compressor over-

load (if no high pressure

switch in system)

LOCKOUT

1. High head pressure

2. Condenser coil poor air circulation (dirty, blocked, damaged)

3. Condenser fan is not running

4. If low pressure switch is open: Refer to Code 3 for troubleshooting

Yellow “ALERT”

Flash Code 3

Short Cycling

Compressor is running only

briefly (four consecutive

cycles of less than three

minutes each)

LOCKOUT

1. If low pressure switch is open:

a. Low refrigerant charge

b. Evaporator blower is not running

c. Evaporator coil is frozen

d. Faulty metering device

e. Condenser coil is dirty

f. Liquid line restriction (filter drier blocked if present)

2. If high pressure switch is open, go to Flash Code 2 information

3. Intermittent thermostat demand signal

4. System or control board defective

Yellow “ALERT”

Flash Code 4

Locked Rotor

LOCKOUT

1. Low line voltage to compressor

2. Excessive liquid refrigerant in compressor

3. Compressor bearings are seized

Yellow “ALERT”

Flash Code 5

Open Circuit 1. Condensing unit power disconnect is open

2. Compressorcircuitbreakerorfusesareopen

3. Compressor contactor has failed open

4. High pressure switch is open and requires manual reset

5. Broken supply wires or connector is not making contact

6. Unusually long compressor protector reset time due to extreme

ambient temperature

7. Compressor windings are damaged

Yellow “ALERT”

Flash Code 6

Missing Phase

LOCKOUT

1. Compressorfuseisopenononephase

2. Broken wire or connector on one phase

3. Compressor motor winding is damaged

4. Utility supply has dropped one phase

Yellow “ALERT”

Flash Code 7

Reverse Phase

LOCKOUT

1. Compressor running backward due to supply phase reversal

Yellow “ALERT”

Flash Code 8

Welded Contactor

Compressor always runs

1. Compressor contactor has failed closed

2. Thermostat demand signal not connected to module

Yellow “ALERT”

Flash Code 9

Low Voltage

Control circuit < 18VAC

1. Control circuit transformer is overloaded

2. Low line voltage to compressor

38AU

Table 12 – CADM Troubleshooting

Miswired Module Indication Recommended Troubleshooting Action

Green LED is not on,

module does not power up

Determine if both R and C module terminals are connected. Verify voltage in present at module’s R

and C terminals.

NOTE: The CADM requires a constant nominal 24VAC power supply. The wiring to the module’s R

and C terminals must be directly from the control transformer. The module cannot receive its power

from another device that will interrupt the 24VAC power supply. See the 38AU Wiring Diagram(s)

(Fig. 29 and Fig. 30).

Green LED Intermittent,

module powers up only

when compressor runs

Determine if R and Y terminals are wired in reverse. Verify module’s R and C terminals have a con-

stant source. See “NOTE” above for details on R and C wiring.

TRIP LED is on but system

and compressor check OK

Verify Y terminal is wired properly per the 38AU wiring diagram (see Fig. 29 and Fig. 30). Verify

voltage at contactor coil falls below 0.5VAC when off. Verify 24VAQC is present across Y and C

when thermostat demand signal is present. If not, R and C are reverse wired.

TRIP LED and ALERT LED

flashing together

Verify R and C terminals are supplied with 19-28VAC.

ALERT Flash Code 3

(Compressor Short Cycling)

displayed incorrectly

Verify Y terminal is connected to 24VAC at contactor coil. Verify voltage at contactor coil falls below

0.5VAC when off.

ALERT Flash Code 5 or 6

(Open Circuit, Missing Phase)

displayed incorrectly

Check that compressor T1 and T3 wires are through module’s current sensing holes. Verify Y ter-

minal is connected to 24VAC at contactor coil. Verify voltage at contactor coil falls below 0.5VAC

when off.

Alert Flash Code *

(Welded Contactor)

displayed incorrectly

Determine if module’s Y terminal is connected. Verify Y terminal is connected to 24VAC at contactor

coil. Verify 24VAC is present across Y and C when thermostat demand signal is present. If not, R

and C are reverse wired. Verify voltage at contactor coil falls below 0.5VAC when off.

Compressor Protection

Compressor Overtemperature Protection (IP) —

A thermostat installed on the compressor motor winding

reacts to excessively high winding temperatures and shuts

off the compressor.

CrankcaseHeater—

The heater minimizes absorption of liquid refrigerant by

oil in the crankcase during brief or extended shutdown

periods. The heater is wired to cycle with the compressor;

the heater is off when compressor is running, and on when

compressor is off.

The crankcase heater will operate as long as the power

circuit is energized. The main disconnect must be on to

energize the crankcase heater.

IMPORTANT: Never open any switch or disconnect

that energizes the crankcase heater unless unit is

being serviced or is to be shut down for a prolonged

period. After a prolonged shutdown on a service job,

energize the crankcase heater for 24 hours before

starting the compressor.

Advanced Scroll Temperature Protection (ASTP) —

See “Advanced Scroll Temperature Protection (ASTP)” on

page 24.

Low-Pressure Switch —

The 38AU low-pressure switch is stem-mounted on the

suction line. Switches are all fixed, non-adjustable type.

High--Pressure Switch —

The high--pressure switch is stem mounted on the

discharge line. The switch is a fixed, non-adjustable type.

Outdoor Fans —

Each fan is supported by a formed-wire mount bolted to

the fan deck and covered with a wire guard. Fan motors

have permanently lubricated bearings.

1. Shut off unit power supply. Install lockout tag.

2. Remove outdoor fan assembly (grille, motor, and fan).

3. Loosen fan hub setscrews.

4. Adjust fan height as shown in Fig. 33.

5. Tighten setscrews to 84 in--lbs (949 N--cm).

6. Replace outdoor fan assembly.

3.6 mm +0/0/-0.8

C10103

Fig. 33 -- Outdoor Fan Blade Position

Lubrication —

Fan Motors: The fan motors have sealed bearings. No

provisions are made for lubrication.

Compressor: The compressor has its own oil supply. Loss

of oil due to a leak in the system should be the only

reason for adding oil after the system has been in

operation.

38AU

Condenser Fans/Motors

Service

Valves

Access Panel -

Control Box &

Compressors

C10087

Fig. 34 -- 38AUD Size 16 Cabinet

C10095

Fig. 35 -- 38AUD*16 Piping

38AU

Equalization

LPS

Oil Equalizer Line

C10079

Fig. 36 -- 38AUZ*16 Compressor Assembly (Rear View)

C10214

Fig. 37 -- 38AUD*16 Compressor Assembly (Rear View)

38AU

Condenser Fans/Motors

Service

Valves

Access Panel -

Control Box &

Compressors

C10089

Fig. 38 -- 38AUZ,D Size 25 Cabinet

CKT

HPS

LPS

HPS

LPS

C10090

Fig. 39 -- 38AUD*25 Piping

38AU

C10215

Fig. 40 -- 38AUZ*25 Compressor Assembly (Rear View)

C10091

Fig. 41 -- 38AUD*25 Compressor Assembly (Rear View)

38AU

Coil Type Identification

38AU units are available with different coil types. Cleaning

methods differ for each type so identifying the coil type is

important. Unit model number and appearance can identify

the coil type.

NOVATIONtType —

The new NOVATION Heat Exchanger Technology is an

all--aluminum construction with louvered serpentine fins

over single--depth crosstubes. The horizontal crosstubes have

large diameter aluminum headers on each end. Various

optional coatings are also available.

38AU units use two--row segmented coils.

TUBES

FINS

MICROCHANNELS

MANIFOLD

C07273

Fig. 42 -- NOVATION Heat Exchanger Coil

Model number designation: See Fig. 3 for general unit

model number format. Position 11 indicates the coil type

and coating. Position 11 values of G, K, T and W indicate

NOVATION coil type is on this unit.

Round--Tube Plate--Fin (RTPF) Type —

This construction uses a series of small diameter copper

hairpin tubes running horizontally with vertical plate fins.

The plate fins may be aluminum (standard) or copper

(optional). Various optional coatings are also available.

These coils may be one--row or two--row.

Model number designation: See Fig. 3 for general unit

model number format. Position 11 indicates the coil type

and coating. Position 11 values of A, B, C, M, N and P

indicate RTPF coil type is on this unit.

NOVATION Coil Cleaning and Maintenance —

To clean the NOVATION condenser coil, chemicals are

NOT to be used; only water is approved as the cleaning

solution. Only clean potable water is authorized for cleaning

NOVATION condensers.

Clean the coil as follows:

1. Turn off unit power.

2. Remove screws holding rear corner posts and top cover

in place. Pivot top cover up 12 to 18 in. (305 to 457

mm) and support with a rigid support. See Fig. 43.

C10216

Fig. 43 -- Pivot and Support Top Cover

3. Carefully remove any foreign objects or debris at-

tached to the coil face or trapped within the mounting

frame and brackets.

4. Using a high pressure water sprayer, purge any soap

or industrial cleaners from hose and/or dilution tank

prior to wetting the coil. Clean condenser face by

spraying the coil core steadily and uniformly from top

to bottom, directing the spray straight into or toward

the coil face. Do not exceed 900 psig or a 45 degree

angle; nozzle must be at least 12 in. (30 cm) from the

coil face. Reduce pressure and use caution to prevent

damage to air centers (fins). Do not fracture the braze

between air centers and refrigerant tubes. Allow water

to drain from the coil core and check for refrigerant

leaks prior to start?up.

5. Replace top cover and rear corner posts.

EQUIPMENT DAMAGE HAZARD

Failure to follow this caution may result in equipment

damage.

Chemical cleaning should NOT be used on the

aluminum microchannel (NOVATION) condenser.

Damage to the coil may occur. Only approved

cleaning is recommended.

CAUTION

Repairing NOVATION Condenser Tube Leaks —

RCD offers service repair kit Part Number 50TJ660007 for

repairing tube leaks in the NOVATION coil crosstubes. This

kit includes approved braze materials (aluminum fluxcore

braze rods), a heat shield, a stainless steel brush, replacement

fin segments, adhesive for replacing fin segments, and

instructions specific to the NOVATION aluminum coil. See

EPIC for instruction sheet 99TA526379.

The repair procedure requires the use of MAPP gas and

torch (must be supplied by servicer) instead of conventional

38AU

oxyacetylene fuel and torch. While the flame temperature

for MAPP is lower than that of oxyacetylene (and thus

provides more flexibility when working on aluminum), the

flame temperature is still higher than the melting

temperature of aluminum, so user caution is required. Follow

instructions carefully. Use the heat shield.

Replacing NOVATIONtCondenser Coil —

The service replacement coil is preformed and is equipped

with transition joints with copper stub tubes. When

brazing the connection joints to the unit tubing, use a wet

cloth around the aluminum tube at the transition joint.

Avoid applying torch flame directly onto the aluminum

tubing.

Routine Cleaning of Round-Tube Plate Fin (RTPF)

Coils —

Periodic cleaning with Totaline®environmentally sound coil

cleaner is essential to extend the life of RTPF coils. This

cleaner is available from Carrier Replacement parts division

as part number P902-0301 for a one gallon container, and

part number P902-0305 for a 5 gallon container. It is

recommended that all RTPF coils be cleaned with the

Totaline environmentally sound coil cleaner as described

below.

NOTE: Do NOT use Totaline®environmentally sound coil

cleaner, or any other coil cleaner on NOVATION coils. See

“NOVATION Coil Cleaning and Maintenance” for

instructions on cleaning NOVATION coils.

Coil cleaning should be part of the unit’s regularly

scheduled maintenance procedures to ensure long life of

the coil. Failure to clean the coils may result in reduced

durability in the environment.

Avoid the use of:

Scoil brighteners

Sacid cleaning prior to painting

Shigh pressure washers

Spoor quality water for cleaning

Totaline environmentally sound coil cleaner is

non-flammable, hypoallergenic, non-bacterial, and a

USDA accepted biodegradable agent that will not harm

the coil or surrounding components such as electrical

wiring, painted metal surfaces, or insulation. Use of

non-recommended coil cleaners is strongly discouraged

since coil and unit durability could be affected.

Totaline Environmentally Sound Coil Cleaner

Application Equipment —

S21/2gallon garden sprayer

Swater rinse with low velocity spray nozzle

UNIT DAMAGE HAZARD

Failure to follow this caution may result in corrosion

and damage to the unit.

Harsh chemicals, household bleach or acid or basic

cleaners should not be used to clean outdoor or indoor

coils or any kind. These cleaners can be very difficult

to rinse out of the coil and can accelerate corrosion at

the fin/tube interface where dissimilar materials are in

contact. If there is dirt below the surface of the coil

use the Totaline environmentally sound coil cleaner as

described above.

CAUTION

UNIT RELIABILITY HAZARD

Failure to follow this caution may result in reduced

unit performance.

High velocity water from a pressure washer, garden

hose, or compressed air should never be used to clean

a coil. The force of the water or air jet will bend the

fin edges and increase airside pressure drop.

CAUTION

Totaline Environmentally Sound Coil Cleaner

Application Instructions:

NOTE: Proper eye protection such as safety glasses is

recommended during mixing and application.

1. Turn off unit power.

2. Remove screws holding rear corner post and top cover

in place. Pivot top cover up 12 to 18 inches (305 to 457

mm) and support with a rigid support. See Fig. 43.

3. Remove all surface loaded fibers and dirt with a vacu-

um cleaner. If a vacuum cleaner is not available, a

soft non-metallic bristle brush may be used. In either

case, the tool should be applied in the direction of the

fins. Coil surfaces can be easily damaged (fin edges

can be easily bent over and damage to the coating of

a protected coil) if the tool is applied across the fins.

NOTE: Use of a water stream, such as a garden hose,

against surface loaded coil will drive the fibers and dirt

into the coil, making cleaning efforts more difficult.

Surface loaded fibers must be completely removed prior

to using low velocity clean water rinse.

4. Using a low velocity garden hose thoroughly wet

finned surfaces with clean water. Be careful not to

bend the fins.

5. Mix Totaline environmentally sound coil cleaner in a

21/2gallon garden sprayer according to the instruc-

tions included with the cleaner. The optimum solution

temperature is 100°F(38°C).

NOTE: Do NOT USE water in excess of 130°F(54°C),

as the enzymatic activity will be destroyed.

6. Thoroughly apply Totaline®environmentally sound

coil cleaner solution to all coil surfaces including the

finned area, tube sheets and coil headers.

38AU

7. Hold garden sprayer nozzle close to finned areas and

apply cleaner with a vertical, up-and-down motion.

Avoid spraying in horizontal pattern to minimize po-

tential for fin damage.

8. Ensure cleaner thoroughly penetrates deep into finned

areas.

9. Interior and exterior finned areas must be thoroughly

cleaned.

10. Finned surfaces should remain wet with cleaning

solution for 10 minutes.

11. Ensure surfaces are not allowed to dry before rinsing.

Reapply cleaner as needed to ensure 10-minute satur-

ation is achieved.

12. Thoroughly rinse all surfaces with low velocity clean

water using downward rinsing motion of water spray

nozzle. Protect fins from damage from the spray

nozzle.

13. Replace top cover and rear corner posts.

FASTENER TORQUE VALUES

Table 13 – Torque Values

Compressor mounting bolts 65---75 in–lbs

(734–847 N–cm)

Condenser fan motor mounting bolts 20 ±2in–lbs

(226 ±23 N–cm)

Condenser fan hub setscrew 84 ±2in–lbs

(949 ±136 N–cm)

High-flow service port 96 ±10 in–lbs

(1085 ±23 N–cm)

Schrader-type service check valve 2–3 in–lbs

(23–34 N–cm)

Compressor oil sightglass thread 330 ±31 in–lbs

(23–34 N–cm)

Compressor to Compressor rail torque 120–168 in–lbs

(1356–1898 N–cm)

Compressor rail to base pan torque 70 ±5in–lbs

(791 ±57 N–cm)

TROUBLESHOOTING

PROBLEM SOLUTION

COMPRESSOR DOES NOT RUN

Contactor Open

1. Power off. 1. Restore power.

2. Fuses blown in field power circuit. 2. After finding cause and correcting, replace with correct size fuse.

3. No control power. 3. Check control transformer primary connections and circuit breaker.

4. Thermostat circuit open. 4. Check thermostat setting.

5. Safety device lockout circuit active. 5. Reset lockout circuit.

6. Low-pressure switch open. 6. Check for refrigerant undercharge, obstruction of indoor airflow. Make

sure liquid line solenoid valve(s) is open.

7. High-pressure switch open. 7. Check for refrigerant overcharge, obstruction of outdoor airflow, air in system.

Be sure outdoor fans are operating correctly.

8. Compressor overtemperature switch open. 8. Check for open condition. Allow for reset. Replace compressor if necessary

9. Loose electrical connections. 9. Tighten all connections.

10. Compressor stuck. 10. See compressor service literature.

Contactor Closed

1. Compressor leads loose. 1. Check connections.

2. Motor windings open. 2. See compressor service literature.

3. Single phasing. 3. Check for blown fuse. Check for loose connection at compressor terminal.

COMPRESSOR STOPS ON HIGH-PRESSURE SWITCH

Outdoor Fan On

1. High-pressure switch faulty. 1. Replace switch.

2. Reversed fan rotation. 2. Confirm rotation, correct if necessary.

3. Airflow restricted. 3. Remove obstruction.

4. Air recirculating. 4. Clear airflow area.

5. Noncondensables in system. 5. Recover refrigerant and recharge as required.

6. Refrigerant overcharge. 6. Recover refrigerant as required.

7. Line voltage incorrect. 7. Consult power company.

8. Refrigerant system restrictions. 8. Check or replace filter drier, expansion valve, etc.

Outdoor Fan Off

1. Fan slips on shaft. 1. Tighten fan hub setscrews.

2. Motor not running. 2. Check power and capacitor.

3. Motor bearings stuck. 3. Replace bearings.

4. Motor overload open. 4. Check overload rating. Check for fan blade obstruction.

5. Motor burned out. 5. Replace motor.

38AU

TROUBLESHOOTING (cont)

PROBLEM SOLUTION

COMPRESSOR CYCLES ON LOW-PRESSURE SWITCH

Indoor-Air Fan Running

1. Liquid line solenoid valve(s) fails to open. 1. Check liquid line solenoid valve(s) for proper operation. Replace if necessary.

2. Filter drier plugged. 2. Replace filter drier.

3. Expansion valve power head defective. 3. Replace power head.

4. Low refrigerant charge. 4. Add charge. Check low-pressure switch setting.

Airflow Restricted

1. Coil iced up. 1. Check refrigerant charge.

2. Coil dirty. 2. Clean coil fins.

3. Air filters dirty. 3. Clean or replace filters.

4. Dampers closed. 4. Check damper operation and position.

Indoor-Air Fan Stopped

1. Electrical connections loose. 1. Tighten all connections.

2. Fan relay defective. 2. Replace relay.

3. Motor overload open. 3. Power supply.

4. Motor defective. 4. Replace motor.

5. Fanbeltbrokenorslipping. 5. Replaceortightenbelt.

COMPRESSOR RUNNING BUT COOLING INSUFFICIENT

Suction Pressure Low

1. Refrigerant charge low. 1. Add refrigerant.

2. Head pressure low. 2. Check refrigerant charge. Check outdoor-air fan thermostat settings.

3. Air filters dirty. 3. Clean or replace filters.

4. Expansion valve power head defective. 4. Replace power head.

5. Indoor coil partially iced. 5. Check low-pressure setting.

6. Indoor airflow restricted. 6. Remove obstruction.

Suction Pressure High

1. Heat load excessive. 1. Check for open doors or windows in vicinity of fan coil.

UNIT OPERATES TOO LONG OR CONTINUOUSLY

1. Low refrigerant charge. 1. Add refrigerant.

2. Control contacts fused. 2. Replace control.

3. Air in system. 3. Purge and evacuate system.

4. Partially plugged expansion valve or filter drier. 4. Clean or replace.

SYSTEM IS NOISY

1. Piping vibration. 1. Support piping as required.

2. Compressor noisy. 2. Replace compressor if bearings are worn.

COMPRESSOR LOSES OIL

1. Leak in system. 1. Repair leak.

2. Crankcase heaters not energized during shutdown. 2. Check wiring and relays. Check heater and replace if defective.

3. Improper interconnecting piping design. 3. Check piping for oil return. Replace if necessary.

FROSTED SUCTION LINE

Expansion valve admitting excess refrigerant. Adjust expansion valve.

HOT LIQUID LINE

1. Shortage of refrigerant due to leak. 1. Repair leak and recharge.

2. Expansion valve opens too wide. 2. Adjust expansion valve.

FROSTEDLIQUIDLINE

1. Restricted filter drier. 1. Remove restriction or replace.

2. Liquid line solenoid valve partially closed. 2. Replace valve.

38AU

APPENDIX A

Air Conditioner & Heat Pump with PURON®

—Quick Reference Guide

SPuron®(R-410A) refrigerant operates at 50 percent to

70 percent higher pressures than R-22. Be sure that

servicing equipment and replacement components are

designed to operate with Puron®.

SPuron®refrigerant cylinders are rose colored.

SRecovery cylinder service pressure rating must be 400

psig, DOT 4BA400 or DOT BW400.

SPuron®systems should be charged with liquid

refrigerant. Use a commercial type metering device in

the manifold hose when charging into suction line with

compressor operating.

SManifold sets should be 700 psig high side and 180 psig

low side with 550 psig low-side retard.

SUse hoses with 700 psig service pressure rating.

SLeak detectors should be designed to detect HFC

refrigerant.

SPuron®, as with other HFCs, is only compatible with

POE oils.

SVacuum pumps will not remove moisture from oil.

SUse only factory specified liquid-line filter driers with

rated working pressures greater than 600 psig.

SDo not install a suction-line filter drier in liquid-line.

SPOE oils absorb moisture rapidly. Do not expose oil to

atmosphere.

SPOE oils may cause damage to certain plastics and

roofing materials.

SWrap all filter driers and service valves with wet cloth

when brazing.

SA factory approved, liquid-line filter drier is required on

every unit.

SDo not use an R-22 TXV.

SIf indoor unit is equipped with a TXV, it must be

changedtoaPuron

®TXV.

SNever open system to atmosphere while it is under a

vacuum.

SWhen system must be opened for service, recover

refrigerant, break vacuum with dry nitrogen before

opening system.

SAlways replace filter drier after opening system for

service.

SDo not vent Puron®into the atmosphere.

SDo not use capillary tube coils.

SObserve all warnings,cautions,andbold text.

SAll Puron®heat pumps must have indoor TXV.

SDo not leave Puron®suction line driers in place for

more than 72 hours.

APPENDIX B

Wiring Diagram List

Unit Electrical Characteristics Diagram Number

38AUD*16 208/230-3-60 38AU500540

460-3-60 38AU500541

575-3-60 38AU500542

38AUD*25 208/230-3-60 38AU500565

460-3-60 38AU500566

575-3-60 38AU500567

38AUZ*16 208/230-3-60 38AU500537

460-3-60 38AU500538

575-3-60 38AU500539

38AUZ*25 208/230-3-60 38AU500568

460-3-60 38AU500569

575-3-60 38AU500570

38AU

APPENDIX C

Low Ambient Option — Factory Installed

Units with the factory installed low ambient option are

equipped with a MotormasterRsolid--state head pressure

control which regulates fan speed. A temperature sensor,

mounted on circuit 1 of the outdoor coil (see Figs. 44 and

45) controls the speed of approved outdoor fan motors in

order to maintain a constant head pressure in the outdoor

coil. The control maintains the appropriate head pressure

at low ambient temperatures down to --20_F(--28_C).

Wind baffles are required to prevent wind cross currents

from causing abnormally low condensing temperatures.

SUse 20--gauge sheet metal to fabricate wind baffles (see

Fig. 46 and Table 14) and mounting brackets (see Fig.

47).

NOTE: Mounting brackets are for use on 15 ton model

units only.

SInstall the wind baffles as show in Fig. 48, for 15 ton

units and Fig. 49, for 20 ton units .

Operation —

Fan on/off control in cooling--only units (38AUZ,

38AUD) is provided by an outdoor fan relay (OFR).

In cooling mode, fan motor speed of outdoor motors

OFM1 and OFM3 is regulated by the speed control

temperature sensor on outdoor coil 1 for a minimum coil

condensing temperature of approximately 100_F(38_C)

at higher outdoor ambient temperature and 80_F(27_C) at

lower ambient. Additionally, outdoor fan motor OFM2

and OFM4 are turned on/off by the low ambient

temperature switch, LAS, operating the low ambient relay

(LAR). The LAS control temperatures are open 42_F+/--

5_F, close 57_F+/--5_F (open 5.5_C+/--2.8_C, close

13.9_C+/--2.8_C).

To override the speed control for full fan speed operation

during service or maintenance, either:

a. remove sensor and place in hot water >120_F

(>49_C), or

b. rewire to bypass control by connecting speed

control input and output power wires.

Troubleshooting —

OBSERVATION POSSIBLE REMEDY

Fans won’t start All fans:

Check power & wiring

Check outdoor fan relay (OFR)

OFM1, OFM3 only:

Check speed control sensor location

Check speed sensor resistance

OFM2, OFM4 only:

Check low ambient switch (LAS)

Check low ambient relay (LAR)

Cooling --- Center outdoor

fans (OFM2, OFM4) off

below approximately 60_F

(16_C) outdoor ambient.

Normal operation

Cooling --- Center outdoor

fans (OFM2, OFM4) not on

above approximately 60_F

(16_C) outdoor ambient

Check low ambient switch (LAS)

Check low ambient relay (LAR)

Cooling --- Slow fan speed

for outer fans (OFM1,

OFM3) at start or during

low outdoor ambient

Normal operation

Cooling --- Slow fan speed

for outer fans (OFM1,

OFM3) above 85_F(29_F)

outdoor ambient (should

be full speed)

Check speed control sensor location

Check speed control sensor

resistance

Check fan motor capacitor

Cooling --- motor current

into speed control is

greater than motor name-

plate FLA

Normal operation

Up to 30% higher A at partial speed

at low ambient

Speed Control Sensor Resistance —

TEMPERATURE RESISTANCE

_F + / --- 2 _F_C + / --- 1 _C Ohms, nominal

--- 2 2 --- 3 0 88350

--- 4 --- 2 0 48485

14 --- 1 0 27650

32 016325

50 10 9950

68 20 6245

77 25 5000

86 30 4028

104 40 2663

122 50 1801

140 60 1244

158 70 876

38AU

Motormaster

Sensor -

Attach to

Circuit 1 coil only.

508 mm (20 in)

for Single Circuit

254 mm (10 in)

for Dual Circuit

C10093

Fig. 44 -- Motormaster Sensor Location:

38AUZ*16 & 38AUD*16 (Novation)

Motormaster Sensor -

Must be positioned

on Vapor Stub of

Circuit 1 coil only.

C10094

Fig. 45 -- Motormaster Sensor Location:

38AUZ*16/25 & 38AUD*16/25 (RTPF)

38AU

Table14–WindBaffleDimension

DIMENSIONS --- INCHES

UNIT BAFFLE A B C D E F G H J

38AUZ*16

38AUD*16

(MCHX)

LEFT SIDE 19 3/420 1/221 1/443 1/883/818 27 1/440 ---

BACK 80 1/481 81 3/443 1/883/818 27 1/440 ---

RIGHT SIDE 38 3/439 1/240 1/443 1/883/818 27 1/440 ---

FRONT 34 1/834 7/835 5/843 1/867/816 1/225 3/438 1/2---

38AUZ*16

38AUD*16

(RTPF)

LEFT SIDE 10 3/411 1/212 1/443 1/841/4 13 1/4 22 1/431 1/440 1/4

BACK 80 1/481 81 3/443 1/883/818 27 1/440 ---

RIGHT SIDE 38 3/439 1/240 1/443 1/883/818 27 1/440 ---

FRONT 27 27 3/428 1/2 43 1/833/412 3/421 3/430 3/439 3/4

38AUZ*25

38AUD*25

(RTPF)

LEFT SIDE 32 7/833 5/834 3/843 1/841/413 1/422 1/431 1/440 1/4

BACK 47 3/448 1/249 1/443 1/841/413 1/422 1/431 1/440 1/4

RIGHT SIDE 61 1/861 7/862 5/843 1/833/412 3/421 3/430 3/439 3/4

FRONT 20 1/820 7/821 5/843 1/833/412 3/421 3/430 3/439 3/4

DIMENSIONS --- MM

UNIT BAFFLE A B C D E F G H J

38AUZ*16

38AUD*16

(MCHX)

LEFT SIDE 501 520 539 1095 212 457 694 1015 ---

BACK 2037 2056 2075 1095 212 457 694 1015 ---

RIGHT SIDE 983 1002 1021 1095 212 457 694 1015 ---

FRONT 866 885 904 1095 174 419 656 977 ---

38AUZ*16

38AUD*16

(RTPF)

LEFT SIDE 272 291 310 1095 108 337 565 794 1022

BACK 2037 2056 2075 1095 212 457 694 1015 ---

RIGHT SIDE 983 1002 1021 1095 212 457 694 1015 ---

FRONT 684 704 723 1095 95 324 552 781 1010

38AUZ*25

38AUD*25

(RTPF)

LEFT SIDE 834 853 872 1095 108 337 565 794 1022

BACK 1214 1233 1252 1095 108 337 565 794 1022

RIGHT SIDE 1551 1570 1589 1095 95 324 552 781 1010

FRONT 510 530 549 1095 95 324 552 781 1010

MCHX: NOVATION coil model

38AU

C10363A

Fig. 46 -- Wind Baffles -- Fabrication

38AU

C10366

Fig. 47 -- 15 Ton Wind Baffle Brackets -- Fabrication

38AU

RIGHT

BACK

LEFT

FRONT

BOTTOM

BRACKET

TOP BRACKETS

C10367

Fig. 48 -- Wind Baffle Installation — 15 Ton Units

38AU

RIGHT

BACK

LEFT

FRONT

C10368

Fig. 49 -- Wind Baffle Installation — 20 Ton Units

38AU

Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.

Catalog No: 38AU---09SI

Replaces: 38AU---07SI

38AU

START-UP CHECKLIST

I. PRELIMINARY INFORMATION

OUTDOOR: MODEL NO. SERIAL NO.

INDOOR: AIRHANDLER MANUFACTURER

MODEL NO. SERIAL NO.

ADDITIONAL ACCESSORIES

II. PRE-START-UP

OUTDOOR UNIT

IS THERE ANY SHIPPING DAMAGE? (Y/N)

IF SO, WHERE:

WILL THIS DAMAGE PREVENT UNIT START-UP? (Y/N)

CHECK POWER SUPPLY. DOES IT AGREE WITH UNIT? (Y/N)

HAS THE GROUND WIRE BEEN CONNECTED? (Y/N)

HAS THE CIRCUIT PROTECTION BEEN SIZED AND INSTALLED PROPERLY? (Y/N)

ARE THE POWER WIRES TO THE UNIT SIZED AND INSTALLED PROPERLY? (Y/N)

CONTROLS

ARE THERMOSTAT AND INDOOR FAN CONTROL WIRING CONNECTIONS MADE AND CHECKED?

(Y/N)

ARE ALL WIRING TERMINALS (including main power supply) TIGHT? (Y/N)

HAS CRANKCASE HEATER BEEN ENERGIZED FOR 24 HOURS? (Y/N)

INDOOR UNIT

HAS WATER BEEN PLACED IN DRAIN PAN TO CONFIRM PROPER DRAINAGE? (Y/N)

ARE PROPER AIR FILTERS IN PLACE? (Y/N)

HAVE FAN AND MOTOR PULLEYS BEEN CHECKED FOR PROPER ALIGNMENT? (Y/N)

DO THE FAN BELTS HAVE PROPER TENSION? (Y/N)

HAS CORRECT FAN ROTATION BEEN CONFIRMED? (Y/N)

PIPING

ARE LIQUID LINE SOLENOID VALVES LOCATED AT THE INDOOR COILS AS REQUIRED? (Y/N)

HAVE LEAK CHECKS BEEN MADE AT COMPRESSOR, OUTDOOR AND INDOOR COILS,

TXVs (Thermostatic Expansion Valves), SOLENOID VALVES, FILTER DRIERS, AND FUSIBLE PLUGS

WITH A LEAK DETECTOR? (Y/N)

LOCATE, REPAIR, AND REPORT ANY LEAKS.

HAVE LIQUID LINE SERVICE VALVES BEEN OPENED? (Y/N)

HAVE SUCTION LINE SERVICE VALVES BEEN OPENED? (Y/N)

38AU

CHECK VOLTAGE IMBALANCE

LINE-TO-LINE VOLTS: AB V AC V BC V

(AB + AC + BC)/3 = AVERAGE VOLTAGE = V

MAXIMUM DEVIATION FROM AVERAGE VOLTAGE = V

VOLTAGE IMBALANCE = 100 X (MAX DEVIATION)/(AVERAGE VOLTAGE) =

IF OVER 2% VOLTAGE IMBALANCE, DO NOT ATTEMPT TO START SYSTEM!

CALL LOCAL POWER COMPANY FOR ASSISTANCE.

CHECK INDOOR UNIT FAN SPEED AND RECORD.

CHECK OUTDOOR UNIT FAN SPEED AND RECORD.

AFTER AT LEAST 10 MINUTES RUNNING TIME, RECORD THE FOLLOWING MEASUREMENTS:

SUCTION PRESSURE CIR 1: CIR 2:

SUCTION LINE TEMP CIR 1: CIR 2:

LIQUID PRESSURE CIR 1: CIR 2:

LIQUID LINE TEMP CIR 1: CIR 2:

ENTERING OUTDOOR UNIT AIR TEMP

LEAVING OUTDOOR UNIT AIR TEMP

INDOOR UNIT ENTERING-AIR DB (dry bulb) TEMP

INDOOR UNIT ENTERING-AIR WB (wet bulb) TEMP

INDOOR UNIT LEAVING-AIR DB TEMP

INDOOR UNIT LEAVING-AIR WB TEMP

COMPRESSOR 1 AMPS (L1/L2/L3) / /

COMPRESSOR 2 AMPS (L1/L2/L3) / /

NOTES:

Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.

Catalog No: 38AU---09SI

Replaces: 38AU---07SI

38AU

Carrier 38Au Users Manual 09SI

38AU to the manual c37178b3-8344-4c06-a11a-0df7c3c65dfd

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