Lenox Air Conditioner Elite Series Xp16 Units Heat Pumps Users Manual 506640a

Lenox Air Conditioner Elite Series XP16 Units Heat Pumps Lennox_XP16_IOM

Elite Series XP16 Units Heat Pumps to the manual 4a0ca56a-af7f-4082-a8f4-4c8427d7732c

2015-02-09

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12/10 506640−01

*2P1210* *P506640-01*

Page 1

E20 Lennox Industries Inc.

Dallas, Texas, USA

These instructions are intended as a

general guide and do not supersede

local codes in any way. Consult

authorities having jurisdiction before

installation.

RETAIN THESE INSTRUCTIONS FOR FUTURE

REFERENCE

NOTICE TO INSTALLER

BRAZING LINE SET TO SERVICE VALVES

It is imperative to follow the brazing technique illustrated starting on

page 11 to avoid damaging the service valve’s internal seals.

WARNING

Improper installation, adjustment, alteration, service or

maintenance can cause personal injury, loss of life, or

damage to property.

Installation and service must be performed by a licensed

professional installer (or equivalent) or a service agency.

IMPORTANT

The Clean Air Act of 1990 bans the intentional venting of

refrigerant (CFCs, HFCs, and HCFCs) as of July 1,

1992. Approved methods of recovery, recycling or

reclaiming must be followed. Fines and/or incarceration

may be levied for noncompliance.

IMPORTANT

This unit must be matched with an indoor coil as

specified in Lennox XP16 Engineering Handbook.

Coils previously charged with HCFC−22 must be

flushed.

CAUTION

Physical contact with metal edges and corners while

applying excessive force or rapid motion can result in

personal injury. Be aware of, and use caution when

working near these areas during installation or while

servicing this equipment.

INSTALLATION

INSTRUCTIONS

Elite® Series XP16 Units

HEAT PUMPS

506640−01

12/10

Supersedes 11/10

TABLE OF CONTENTS

Shipping and Packing List 1. . . . . . . . . . . . . . . . . . . . . .

General 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Model Number Identification 2. . . . . . . . . . . . . . . . . . . .

Unit Dimensions 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Typical Parts Arrangement 3. . . . . . . . . . . . . . . . . . . . . .

Caps and Fasteners Torque Requirements 3. . . . . . . .

Operating Gauge Set and Service Valves 3. . . . . . . . .

Recovering Refrigerant from Existing System 5. . . . .

New Outdoor Unit Placement 6. . . . . . . . . . . . . . . . . . .

Removing and Installing Panels 8. . . . . . . . . . . . . . . . .

Line Set Requirements 9. . . . . . . . . . . . . . . . . . . . . . . . .

Brazing Connections 11. . . . . . . . . . . . . . . . . . . . . . . . . . .

Indoor Refrigerant Metering Device Removal and

Flushing Line Set and Indoor Coil 14. . . . . . . . . . . . . . . .

Installing New Indoor Metering Device 15. . . . . . . . . . . .

Leak Test Line Set and Indoor Coil 16. . . . . . . . . . . . . . .

Evacuating Line Set and Indoor Coil 17. . . . . . . . . . . . .

Electrical Connections 18. . . . . . . . . . . . . . . . . . . . . . . . .

Unit Start−Up 23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Servicing and Weighing In Refrigerant for Units

Delivered Void of Charge 24. . . . . . . . . . . . . . . . . . . . . . .

Optimizing System Refrigerant Charge 26. . . . . . . . . . .

System Operation 30. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Defrost System 34. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Two−Stage Modulation Compressors Checks 40. . . . . .

Maintenance 40. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Checklists 42. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Shipping and Packing List

Check unit for shipping damage. Consult last carrier

immediately if damage is found.

1 − Assembled outdoor unit

General

The XP16 outdoor unit uses HFC−410A refrigerant. This

unit must be installed with a matching indoor blower coil

and line set as outlined in the XP16 Lennox Engineering

Handbook. Elite® Series outdoor units are designed for

use in check / expansion valve (CTXV) systems only and

are not to be used with other refrigerant flow control

devices. An indoor coil check / expansion valve approved

for use with HFC−410A must be ordered separately and

installed prior to operating the unit.

Litho U.S.A.

Page 2

Model Number Identification

P 16 036− −

Unit Type

P = Heat Pump

Series

Nominal Cooling Capacity

024 = 2 tons

036 = 3 tons

048 = 4 tons

060 = 5 tons

Minor Revision Number

230

Voltage

230 = 208/230V−1ph−60hz

Refrigerant Type

X = R−410A

X−05

Unit Dimensions − inches (mm)

ELECTRICAL

INLETS

SIDE VIEW

DISCHARGE AIR

VAPOR LINE

CONNECTION

LIQUID LINE

CONNECTION

4−1/4

(108)

4−3/4

(121)

1 (25)

2 (51)

SIDE VIEW

UNIT SUPPORT

FEET

8−1/2

(216) D

XP16−024 BASE SECTION

8−3/4

(222)

5−1/2

(140)

9−1/2

(241)

8−1/4

(210)

13−1/2

(343)

UNIT SUPPORT FEET

XP16 BASE WITH LEGS

Mode Number A B C D E F G H J K

XP16−024−230 35 (889) 27 (686) 28 (711) −−−−−−−

XP16−036−230 39 (991) 30−1/2 (775) 35 (889) 13−7/8 (352) 7−3/4 (197) 3−1/4 (83) 27−1/8 (689) 3−5/8 (92) 4−1/2 (114) 20−5/8 (524)

XP16−048−230 35 (889) 35−1/2 (902) 39−1/2

(1003)

16−7/8 (429) 8−3/4 (222) 3−1/8 (79) 30−3/4 (781) 4−5/8 (117) 3−3/4 (95) 26−7/8 (683)

XP16−060−230 45 (1143 35−1/2 (902) 39−1/2

(1003)

Page 3

XP16 SERIES

Typical Unit Parts Arrangement

CHECK /

EXPANSION

VALVE

VAPOR VALVE AND GAUGE PORT /

SUCTION LINE CONNECTIONS

EXPANSION VALVE

SENSING BULB

LOW PRESSURE

SWITCH (S87)

LIQUID LINE

BI−FLOW FILTER

DRIER

HIGH PRESSURE

SWITCH (S4)

COMPRESSOR

LIQUID VALVE AND GAUGE

PORT / LIQUID LINE

CONNECTIONS

REVERSING

VALVE (L1)

DEMAND DEFROST

CONTROL (A108)

SINGLE POLE

CONTACTOR

(K1)

GROUND

LUG AMBIENT

TEMPERATURE

SENSOR (RT13)

TRUE SUCTION

PORT

DISCHARGE LINE

SENSOR (RT28)

XP16−024

COIL SENSOR −THIRD

HAIRPIN DOWN FROM

THE TOP ON INSIDE

ROW.

XP16−036

COIL SENSOR − NINTH

HAIRPIN UP FROM THE

BOTTOM ON INSIDE

ROW.

XP16−048

COIL SENSOR − EIGHT HAIRPIN

UP FROM THE BOTTOM ON

INSIDE ROW.

XP16−060

COIL SENSOR −

SIXTH HAIRPIN UP

FROM THE BOTTOM

ON INSIDE ROW.

DUAL RUN CAPACITOR (C12)

(−024, −036 AND −048 ONLY)

DETAIL A

FOR COIL SENSOR (RT21)

LOCATION SEE DETAIL A

SINGLE RUN CAPACITOR (C1)

(−060 ONLY)

Figure 1. Unit Parts Arrangement

Caps and Fasteners Torque Requirements

IMPORTANT

Only use Allen wrenches of sufficient hardness (50Rc −

Rockwell Harness Scale minimum). Fully insert the

wrench into the valve stem recess.

Service valve stems are factory−torqued (from 9 ft−lbs for

small valves, to 25 ft−lbs for large valves) to prevent

refrigerant loss during shipping and handling. Using an

Allen wrench rated at less than 50Rc risks rounding or

breaking off the wrench, or stripping the valve stem

recess.

See the Lennox Service and Application Notes

Corp.0807−L5 (C−08−1) for further details and

information.

When servicing or repairing HVAC equipment and

components, ensure the fasteners are appropriately

tightened. Table 1 list torque values for various caps and

fasteners.

Table 1. Torque Requirements

Parts Recommended Torque

Service valve cap 8 ft.− lb. 11 NM

Sheet metal screws 16 in.− lb. 2 NM

Machine screws #10 28 in.− lb. 3 NM

Compressor bolts 90 in.− lb. 10 NM

Gauge port seal cap 8 ft.− lb. 11 NM

Page 4

Operating Gauge Set and Service Valves

IMPORTANT

To prevent stripping of the various caps used, the

appropriately sized wrench should be used and fitted

snugly over the cap before tightening.

OPERATING SERVICE VALVES

The liquid and vapor line service valves are used for

refrigerant recovery, flushing, leak testing, evacuating,

weighing in refrigerant and optimizing system charge.

Each valve is equipped with a service port which has a

factory−installed valve core. Figure 2 provides information

on how to access and operate both angle− and ball−type

service valves.

USING MANIFOLD GAUGE SET

When checking the system charge, only use a manifold

gauge set that features low−loss anti−blow back fittings.

Manifold gauge set used for HFC−410A refrigerant

systems must be capable of handling the higher system

operating pressures. The manifold gauges should be rated

for:

SHigh side  Pressure range of 0 − 800 pound−force per

square inch gauge (psig)

SLow side  Use with 30" vacuum to 250 psig with

dampened speed to 500 psig

SManifold gauge set hoses must be rated for use to 800

psig of pressure with a 4000 psig burst rating.

INSERT HEX−HEAD

EXTENSION HERE

SERVICE PORT CORE

SERVICE PORT CAP

SERVICE PORT

CORE

TO OUTDOOR UNIT STEM CAP

(VALVE STEM SHOWN OPEN)

INSERT HEX WRENCH HERE

TO INDOOR

UNIT

BALL (SHOWN CLOSED)

SERVICE PORT CORE

TO INDOOR UNIT

TO OUTDOOR UNIT

ATo open rotate stem

counterclockwise

90°.

BTo close rotate stem

clockwise 90°.

SERVICE PORT

SERVICE PORT CAP

REMOVE

STEM CAP

VALVE STEM

Operating Angle−Type Service Valve:

1. Remove stem cap with an appropriately sized wrench.

2. Use a service wrench with a hex−head extension (3/16" for liquid line valve sizes and 5/16"

for vapor line valve sizes) to back the stem out counterclockwise as far as it will go to open

the service valve.

Operating Ball−Type Service Valve:

1. Remove stem cap with an appropriately sized wrench.

2. Use an appropriately sized wrenched to open.

11 12

1/12 TURN

To Access Service Port:

A service port cap protects the service port core from

contamination and serves as the primary leak seal.

1. Remove service port cap with an appropriately sized

wrench.

2. Connect gauge set to service port.

3. When testing is completed, replace service port cap and

tighten as follows:

SWith torque wrench: Finger tighten and torque cap per table 1.

SWithout torque wrench: Finger tighten and use an appropriately sized

wrench to turn an additional 1/6 turn clockwise.

11 12

1/6 TURN

When service valve stem is in the CLOSED position,

the service port is open to the line set and indoor unit.

When service valve is OPEN, the service port is open to line set,

indoor and outdoor unit.

Reinstall Stem Cap:

Stem cap protects the valve stem from damage and

serves as the primary seal. Replace the stem cap and

tighten as follows:

SWith Torque Wrench: Finger tighten and then

torque cap per table 1.

SWithout Torque Wrench: Finger tighten and use an

appropriately sized wrench to turn an additional 1/12 turn clockwise.

NOTE  A label with specific torque requirements may be affixed to the stem cap. If the label is present, use the specified torque.

TO INDOOR

UNIT

TO OUTDOOR

UNIT

REMOVE

STEM CAP

VALVE STEM

SHOWN

CLOSED

Figure 2. Angle and Ball−Type Service Valves

Page 5

XP16 SERIES

Recovering Refrigerant from Existing System

Disconnect all power to the existing outdoor unit at the disconnect

switch and/or main fuse box/breaker panel.

DISCONNECT POWER CONNECT MANIFOLD GAUGE SET

MANIFOLD GAUGES

RECOVERY MACHINE

CLEAN RECOVERY

CYLINDER

OUTDOOR UNIT

HIGH

LOW

Connect a manifold gauge set, clean recovery cylinder and a

recovery machine to the service ports of the existing unit..

METHOD 1:

Use Method 1 if the existing outdoor unit is not equipped with shut−off valves, or

if the unit is not operational and you plan to use the existing HCFC−22 to flush

the system.

Recover all HCFC−22 refrigerant from the existing system using a recovery

machine and clean recovery cylinder. Check gauges after shutdown to confirm

that the entire system is completely void of refrigerant.

METHOD 2:

Use Method 2 if the existing outdoor unit is equipped with manual shut−off valves,

and you plan to use new HCFC−22 refrigerant to flush the system.

Perform the following task:

A Start the existing HCFC−22 system in the cooling mode and close the liquid line

valve.

B Use the compressor to pump as much of the existing HCFC−22 refrigerant into

the outdoor unit until the outdoor system is full. Turn the outdoor unit main power

OFF and use a recovery machine to remove the remaining refrigerant from the

system.

NOTE  It may be necessary to bypass the low pressure switches (if equipped) to

ensure complete refrigerant evacuation.

C When the low side system pressures reach 0 psig, close the vapor line valve.

D Check gauges after shutdown to confirm that the valves are not allowing

refrigerant to flow back into the low side of the system.

Remove existing HCFC−22 refrigerant using one of the following procedures:

RECOVERING REFRIGERANT

DISCONNECT

SWITCH

MAIN FUSE

BOX/BREAKER

PANEL

NOTE  Use the recovery machine instructions to make

the correct manifold gauge set connections for recovery

refrigerant. The illustration below is a typical connection.

NOTE  When using Method 2, the listed devices

below could prevent full system charge recovery into

the outdoor unit:

SOutdoor unit’s high or low−pressure switches (if

applicable) when tripped can cycle the

compressor OFF.

SCompressor can stop pumping due to tripped

internal pressure relief valve.

SCompressor has internal vacuum protection that

is designed to unload the scrolls (compressor

stops pumping) when the pressure ratio meets a

certain value or when the suction pressure is as

high as 20 psig. (Compressor suction

pressures should never be allowed to go into

a vacuum. Prolonged operation at low suction

pressures will result in overheating of the

scrolls and permanent damage to the scroll

tips, drive bearings and internal seals.)

Once the compressor can not pump down to a lower

pressure due to any of the above mentioned system

conditions, shut off the vapor valve. Turn OFF the main

power to unit and use a recovery machine to recover

any refrigerant left in the indoor coil and line set.

METHOD 2 LIMITATIONS

Figure 3. Refrigerant Recovery

IMPORTANT

The Environmental Protection Agency (EPA) prohibits the intentional venting of HFC refrigerants during maintenance,

service, repair and disposal of appliance. Approved methods of recovery, recycling or reclaiming must be followed.

WARNING

Refrigerant can be harmful if it is inhaled. Refrigerant must be used and recovered responsibly.

Failure to follow this warning may result in personal injury or death.

Page 6

New Outdoor Unit Placement

CAUTION

In order to avoid injury, take proper precaution when lift-

ing heavy objects.

Remove existing outdoor unit prior to placement of new

outdoor unit. See Unit Dimensions on page 2 for sizing

mounting slab, platforms or supports. Refer to figure 4 for

mandatory installation clearance requirements.

POSITIONING CONSIDERATIONS

Consider the following when positioning the unit:

SSome localities are adopting sound ordinances based

on the unit’s sound level registered from the adjacent

property, not from the installation property. Install the

unit as far as possible from the property line.

SWhen possible, do not install the unit directly outside

a window. Glass has a very high level of sound

transmission. For proper placement of unit in relation

to a window see the provided illustration in figure 5,

detail A.

PLACING UNIT ON SLAB

When installing unit at grade level, the top of the slab

should be high enough above grade so that water from

higher ground will not collect around the unit. The slab

should have a slope tolerance as described in figure 5,

detail B.

NOTE  If necessary for stability, anchor unit to slab as

described in figure 5, detail D.

ELEVATING THE UNIT

Units are outfitted with elongated support feet as illustrated

in figure 5, detail C.

If additional elevation is necessary, raise the unit by

extending the height of the unit support feet. This may be

achieved by using a 2 inch (50.8mm) schedule 40 female

threaded adapter.

The specified coupling will fit snuggly into the recessed

portion of the feet. Use additional 2 inch (50.8mm)

Schedule 40 male threaded adaptors which can be

threaded into the female threaded adaptors to make

additional adjustments to the level of the unit.

NOTE  Keep the height of extenders short enough to

ensure a sturdy installation. If it is necessary to extend

further, consider a different type of field−fabricated

framework that is sturdy enough for greater heights.

ROOF MOUNTING

Install the unit a minimum of 6 inches (152 mm) above the

roof surface to avoid ice build−up around the unit. Locate

the unit above a load bearing wall or area of the roof that

can adequately support the unit. Consult local codes for

rooftop applications. See figure 5, detail F for other roof top

mounting considerations.

NOTICE

Roof Damage!

This system contains both refrigerant and oil. Some

rubber roofing material may absorb oil and cause the

rubber to swell when it comes into contact with oil. The

rubber will then bubble and could cause leaks. Protect

the roof surface to avoid exposure to refrigerant and oil

during service and installation. Failure to follow this

notice could result in damage to roof surface.

CONTROL PANEL

ACCESS

LOCATION

6 (152)

36 (914)

12 (305) 30 (762)

LINE SET

CONNECTIONS

(610)

48 (1219)

MINIMUM CLEARANCE BETWEEN TWO UNITS

CLEARANCE ON ALL SIDES  INCHES (MILLIMETERS)

ACCESS PANEL

MINIMUM CLEARANCE

ABOVE UNIT

NOTES:

SClearance to one of the other three

sides must be 36 inches (914mm).

SClearance to one of the remaining

two sides may be 12 inches

(305mm) and the final side may be

6 inches (152mm).

Figure 4. Installation Clearances

Page 7

XP16 SERIES

LEG DETAIL

BASE

2" (50.8MM) SCH 40

FEMALE THREADED

ADAPTER

Concrete slab  use two plastic anchors (hole

drill 1/4")

Wood or plastic slab  no plastic anchor (hole

drill 1/8")

COIL

BASE PAN

CORNER POST

STABILIZING BRACKET (18 GAUGE

METAL  2" WIDTH; HEIGHT AS

REQUIRED)

 Slab Side Mounting

#10 1/2" LONG SELF−DRILLING

SHEET METAL SCREWS

#10 1−1/4" LONG HEX HD SCREW

AND FLAT WASHER

Stabilizing bracket (18 gauge metal  2" (50.8mm) width; height as required); bend to form

right angle as exampled below.

FOR EXTRA

STABILITY

 Deck Top Mounting

Elevated Slab Mounting

using Feet Extenders

Install unit level or, if on a slope, maintain slope tolerance of two (2)

degrees (or two inches per five feet [50 mm per 1.5 m]) away from

building structure.

MOUNTING

SLAB

BUILDING

STRUCTURE

GROUND LEVEL

 Outside Unit Placement  Slab Mounting at Ground Level

SAME FASTENERS AS

SLAB SIDE MOUNTING.

DETAIL A DETAIL B

DETAIL C DETAIL D

2" (50.8MM) SCH 40

MALE THREADED

ADAPTER

Use additional 2" SCH 40 male threaded adapters which

can be threaded into the female threaded adapters to

make additional adjustments to the level of the unit.

TWO 90° ELBOWS INSTALLED IN LINE SET WILL

REDUCE LINE SET VIBRATION.

Install unit away from windows.

One bracket per side

(minimum). For extra

stability, two brackets per

side, two inches (51mm)

from each corner.

DETAIL E

MINIMUM ONE

PER SIDE

DETAIL F

WIND BARRIER

INLET AIR

INLET AIR INLET AIR

INLET AIR

PREVAILING WINTER WINDS

 Roof Top Mounting

If unit coil cannot be mounted away from prevailing winter winds, a wind barrier should be

constructed. Size barrier at least the same height and width as outdoor unit. Mount barrier 24

inches (610 mm) from the sides of the unit in the direction of prevailing winds as illustrated.



Figure 5. Placement, Slab Mounting and Stabilizing Unit

Page 8

Removing and Installing Panels

LOUVERED PANEL REMOVAL

Remove the louvered panels as follows:

1. Remove two screws, allowing the panel to swing open

slightly.

2. Hold the panel firmly throughout this procedure. Rotate

bottom corner of panel away from hinged corner post until

lower three tabs clear the slots as illustrated in detail B.

3. Move panel down until lip of upper tab clears the top slot in

corner post as illustrated in detail A.

LOUVERED PANEL INSTALLATION

Position the panel almost parallel with the unit as illustrated in

detail D with the screw side as close to the unit as possible.

Then, in a continuous motion:

1. Slightly rotate and guide the lip of top tab inward as

illustrated in detail A and C; then upward into the top

slot of the hinge corner post.

2. Rotate panel to vertical to fully engage all tabs.

3. Holding the panel’s hinged side firmly in place, close

the right−hand side of the panel, aligning the screw

holes.

4. When panel is correctly positioned and aligned, insert

the screws and tighten.

Detail A

ROTATE IN THIS DIRECTION;

THEN DOWN TO REMOVE

PANEL

SCREW

HOLES

LIP

IMPORTANT! DO NOT ALLOW PANELS TO HANG ON UNIT BY TOP TAB. TAB IS FOR

ALIGNMENT AND NOT DESIGNED TO SUPPORT WEIGHT OF PANEL.

PANEL SHOWN SLIGHTLY ROTATED TO ALLOW TOP TAB TO EXIT (OR

ENTER) TOP SLOT FOR REMOVING (OR INSTALLING) PANEL.

MAINTAIN MINIMUM PANEL ANGLE (AS CLOSE TO

PARALLEL WITH THE UNIT AS POSSIBLE) WHILE

INSTALLING PANEL.

PREFERRED ANGLE

FOR INSTALLATION

ANGLE MAY BE TOO

EXTREME

HOLD DOOR FIRMLY TO THE HINGED

SIDE TO MAINTAIN

FULLY−ENGAGED TABS

Detail C

Detail B

Detail D

Figure 6. Removing and Installing Panels

WARNING

To prevent personal injury, or damage to panels, unit or structure, be sure to observe the following:

While installing or servicing this unit, carefully stow all removed panels out of the way, so that the panels will not cause

injury to personnel, nor cause damage to objects or structures nearby, nor will the panels be subjected to damage (e.g.,

being bent or scratched).

While handling or stowing the panels, consider any weather conditions, especially windy conditions, that may cause

panels to be blown around and battered.

Page 9

XP16 SERIES

Line Set Requirements

This section provides information on: installation of new or

replacement line set.

SAdding Polyol ester oil requirements

SNew or replacement line set installation

SUsing existing line set.

ADDING POLYOL ESTER OIL REQUIREMENTS

IMPORTANT

Mineral oils are not compatible with HFC−410A. If oil

must be added, it must be a Polyol Ester oil.

The compressor is charged with sufficient Polyol Ester oil

(POE) for line set lengths up to 50 feet. Recommend

adding oil to system based on the amount of refrigerant

charge in the system. Systems with 20 pounds or less of

refrigerant required no oil to be added.

For systems over 20 pounds − add one ounce for every five

(5) pounds of HFC−410A refrigerant.

Recommended topping−off POE oils are Mobil EAL

ARCTIC 22 CC or ICI EMKARATEt RL32CF.

NEW OR REPLACEMENT LINE SET INSTALLATION

Field refrigerant piping consists of both liquid and vapor

lines from the outdoor unit to the indoor coil. Use Lennox

L15 (sweat, non−flare) series line set, or field−fabricated

refrigerant line sizes as specified in table 2.

If refrigerant lines are routed through a wall, then seal and

isolate the opening so vibration is not transmitted to the

building. Pay close attention to line set isolation during

installation of any HVAC system. When properly isolated

from building structures (walls, ceilings. floors), the

refrigerant lines will not create unnecessary vibration and

subsequent sounds. See figure 7 for recommended

installation practices.

NOTE  When installing refrigerant lines longer than 50

feet, see the Lennox Refrigerant Piping Design and

Fabrication Guidelines, CORP. 9351−L9, or contact

Lennox Technical Support Product Applications for

assistance. To obtain the correct information from Lennox,

be sure to communicate the following information:

SModel (XP16) and size of unit (e.g. −036).

SLine set diameters for the unit being installed as listed

in table 2 and total length of installation.

SNumber of elbows vertical rise or drop in the piping.

USING EXISTING LINE SET

Things to consider:

SLiquid line that meter the refrigerant, such as RFC1

liquid line, must not be used in this application.

SExisting line set of proper size as listed in table 2 may

be reused.

SIf system was previously charged with HCFC−22

refrigerant, then existing line set must be flushed (see

Flushing Line Set and Indoor Coil on page 14).

If existing line set is being used, then proceed to Brazing

Connections on page 11.

IMPORTANT

Lennox highly recommends changing line set when

converting the existing system from HCFC−22 to

HFC−410A. If that is not possible and the line set is the

proper size as reference in table 2, use the procedure

outlined under Flushing Line Set and Indoor Coil on page

13.

IMPORTANT

If this unit is being matched with an approved line set

or indoor unit coil which was previously charged with

mineral oil, or if it is being matched with a coil which

was manufactured before January of 1999, the coil

and line set must be flushed prior to installation. Take

care to empty all existing traps. Polyol ester (POE) oils

are used in Lennox units charged with HFC−410A

refrigerant. Residual mineral oil can act as an

insulator, preventing proper heat transfer. It can also

clog the expansion device, and reduce the system

performance and capacity.

Failure to properly flush the system per the

instructions below will void the warranty.

Table 2. Refrigerant Line Set  Inches (mm)

Model Field Connections Recommended Line Set

Liquid Line Suction Line Liquid Line Suction Line L15 Line Set

XP16−024−230 3/8" (10 mm) 3/4" (19 mm) 3/8" (10 mm) 3/4" (19 mm) L15−41  15 ft. − 50 ft. (4.6m − 15 m)

XP16−036−230

3/8" (10 mm) 7/8" (22 mm) 3/8" (10 mm) 7/8" (22 mm) L15−65  15 ft. − 50 ft. (4.6 m − 15 m)

XP16−048−230

XP16−060−230 3/8" (10 mm) 1−1/8" (29 mm) 3/8" (10 mm) 1−1/8" (29 mm) Field Fabricated

NOTE  Some applications may required a field provided 7/8" to 1−1/8" adapter

Page 10

ANCHORED HEAVY NYLON

WIRE TIE OR AUTOMOTIVE

MUFFLER-TYPE HANGER

STRAP LIQUID LINE TO

VAPOR LINE

WALL

STUD

LIQUID LINE

NON−CORROSIVE

METAL SLEEVE

VAPOR LINE − WRAPPED

IN ARMAFLEX

AUTOMOTIVE

MUFFLER-TYPE HANGER

REFRIGERANT LINE SET  TRANSITION

FROM VERTICAL TO HORIZONTAL

Line Set Isolation  The following illustrations are examples of proper refrigerant line set isolation:

STRAPPING

MATERIAL (AROUND

VAPOR LINE ONLY)

TAPE OR

WIRE TIE

WIRE TIE (AROUND

VAPOR LINE ONLY)

FLOOR JOIST OR

ROOF RAFTER

TAPE OR

WIRE TIE

To hang line set from joist or rafter, use either metal strapping material

or anchored heavy nylon wire ties.

8 FEET (2.43 METERS)

STRAP THE VAPOR LINE TO THE JOIST

OR RAFTER AT 8 FEET (2.43 METERS)

INTERVALS THEN STRAP THE LIQUID

LINE TO THE VAPOR LINE.

FLOOR JOIST OR

ROOF RAFTER

REFRIGERANT LINE SET  INSTALLING

HORIZONTAL RUNS

NOTE  Similar installation practices should be used if line set is

to be installed on exterior of outside wall.

PVC

PIPE

FIBERGLASS

INSULATION

CAULK

OUTSIDE

WALL

VAPOR LINE WRAPPED

WITH ARMAFLEX

LIQUID

LINE

OUTSIDE WALL LIQUID LINE

VAPOR LINE

WOOD BLOCK

BETWEEN STUDS

STRAP

WOOD BLOCK

STRAP

SLEEVE

WIRE TIE

INSIDE WALL

REFRIGERANT LINE SET  INSTALLING

VERTICAL RUNS (NEW CONSTRUCTION SHOWN)

NOTE  Insulate liquid line when it is routed through areas where the

surrounding ambient temperature could become higher than the

temperature of the liquid line or when pressure drop is equal to or greater

than 20 psig.

NON−CORROSIVE

METAL SLEEVE

NON−CORROSIVE

METAL SLEEVE

8 FEET (2.43 METERS)

Figure 7. Line Set Installation

Page 11

XP16 SERIES

Brazing Connections

Use the procedures outline in figures 8 and 9 for brazing line set connections to service valves.

WARNING

Polyol Ester (POE) oils used with HFC−410A

refrigerant absorb moisture very quickly. It is very

important that the refrigerant system be kept closed

as much as possible. DO NOT remove line set caps

or service valve stub caps until you are ready to make

connections.

WARNING

Danger of fire. Bleeding the refrigerant

charge from only the high side may result

in pressurization of the low side shell and

suction tubing. Application of a brazing

torch to a pressurized system may result

in ignition of the refrigerant and oil

mixture − Check the high and low

pressures before applying heat.

WARNING

When using a high pressure gas such as

dry nitrogen to pressurize a refrigeration

or air conditioning system, use a

regulator that can control the pressure

down to 1 or 2 psig (6.9 to 13.8 kPa).

CAUTION

Brazing alloys and flux contain materials which are

hazardous to your health.

Avoid breathing vapors or fumes from brazing

operations. Perform operations only in well−ventilated

areas.

Wear gloves and protective goggles or face shield to

protect against burns.

Wash hands with soap and water after handling brazing

alloys and flux.

IMPORTANT

Allow braze joint to cool before removing the wet rag

from the service valve. Temperatures above 250ºF can

damage valve seals.

IMPORTANT

Use silver alloy brazing rods with 5% minimum silver

alloy for copper−to−copper brazing. Use 45% minimum

alloy for copper−to−brass and copper−to−steel brazing.

WARNING

Fire, Explosion and Personal Safety

Hazard.

Failure to follow this warning could

result in damage, personal injury or

death.

Never use oxygen to pressurize or

purge refrigeration lines. Oxygen,

when exposed to a spark or open

flame, can cause fire and/or an ex-

plosion, that could result in property

damage, personal injury or death.

Page 12

ATTACH THE MANIFOLD GAUGE SET FOR BRAZING LIQUID AND SUCTION / VAPOR LINE SERVICE

VALVES

OUTDOOR

UNIT

LIQUID LINE

VAPOR LINE

LIQUID LINE SERVICE

VALVE

SUCTION /

VAPOR LINE

SERVICE

VALVE

ATTACH

GAUGES

INDOOR

UNIT

SUCTION / VAPOR SERVICE PORT MUST BE

OPEN TO ALLOW EXIT POINT FOR NITROGEN

A Connect gauge set low pressure side to

liquid line service valve (service port).

B Connect gauge set center port to bottle of

nitrogen with regulator.

C Remove core from valve in suction / vapor

line service port to allow nitrogen to escape.

NITROGEN

HIGHLOW

USE REGULATOR TO FLOW

NITROGEN AT 1 TO 2 PSIG.

WHEN BRAZING LINE SET TO

SERVICE VALVES, POINT FLAME

AWAY FROM SERVICE VALVE.

Flow regulated nitrogen (at 1 to 2 psig) through the low−side refrigeration gauge set into the liquid line service port valve, and out of the suction /

vapor line service port valve.

CUT AND DEBUR CAP AND CORE REMOVAL

Cut ends of the refrigerant lines square (free from nicks or dents)

and debur the ends. The pipe must remain round. Do not crimp end

of the line.

Remove service cap and core from

both the suction / vapor and liquid line

service ports.

LIQUID LINE SERVICE

VALVE

SERVICE

PORT

CORE

SERVICE PORT

CAP

SERVICE

PORT

CORE

SERVICE

PORT CAP

CUT AND DEBUR

LINE SET SIZE MATCHES

SERVICE VALVE CONNECTION

COPPER TUBE

STUB

SERVICE VALVE

CONNECTION

REFRIGERANT LINE

DO NOT CRIMP SERVICE VALVE

CONNECTOR WHEN PIPE IS

SMALLER THAN CONNECTION

REDUCER

SUCTION / VAPOR LINE

SERVICE VALVE

LINE SET SIZE IS SMALLER

THAN CONNECTION

Figure 8. Brazing Procedures

WARNING

When using a high pressure gas such as dry nitrogen to pressurize a refrigeration or air conditioning

system, use a regulator that can control the pressure down to 1 or 2 psig (6.9 to 13.8 kPa).

Page 13

XP16 SERIES

WHEN BRAZING LINE SET TO

SERVICE VALVES, POINT FLAME

AWAY FROM SERVICE VALVE.

LIQUID LINE SERVICE VALVE

LIQUID LINE

BRAZE LINE SET

Wrap both service valves with water saturated cloths as illustrated here and as mentioned in step 4, before brazing to line set. Water

saturated cloths must remain water saturated throughout the brazing and cool−down process.

WATER SATURATED

CLOTH

IMPORTANT  Allow braze joint to cool. Apply

additional water saturated cloths to help cool brazed

joint. Do not remove water saturated cloths until piping

has cooled. Temperatures above 250ºF will damage

valve seals.

SUCTION / VAPOR LINE

WATER SATURATED

CLOTH

SUCTION / VAPOR LINE

SERVICE VALVE

After all connections have been brazed, disconnect manifold gauge set from service ports. Apply additional water saturated cloths to both

service valves to cool piping. Once piping is cool, remove all water saturated cloths.

WHEN BRAZING LINE SET TO

SERVICE VALVES, POINT FLAME

AWAY FROM SERVICE VALVE.

PREPARATION FOR NEXT STEP

WARNING

1. FIRE, PERSONAL INJURY, OR PROPERTY

DAMAGE may result if you do not wrap a water

saturated cloth around both liquid and suction line

service valve bodies and copper tube stub while

brazing in the line set! The braze, when complete,

must be quenched with water to absorb any residual

heat.

2. Do not open service valves until refrigerant lines and

indoor coil have been leak−tested and evacuated.

Refer to procedures provided in this supplement.

WRAP SERVICE VALVES

To help protect service valve seals during brazing, wrap water saturated cloths around service valve bodies and copper tube stubs. Use

additional water saturated cloths underneath the valve body to protect the base paint.

FLOW NITROGEN

Flow regulated nitrogen (at 1 to 2 psig) through the refrigeration gauge set into the valve stem port connection on the liquid service valve and

out of the suction / vapor valve stem port. See steps 3A, 3B and 3C on manifold gauge set connections

Figure 9. Brazing Procedures (continued)

Page 14

Indoor Refrigerant Metering Device Removal and Flushing Line Set and Indoor Coil

Flushing is only required when the existing system used HCFC−22 refrigerant. If the existing system used HFC−410a, then

remove the original indoor coil metering device and proceed to Installing New Indoor Metering Device on page 15.

SENSING

LINE

TEFLON® RING

FIXED ORIFICE

BRASS NUT

LIQUID LINE ASSEMBLY

(INCLUDES STRAINER)

LIQUID LINE ORIFICE HOUSING

DISTRIBUTOR TUBES

DISTRIBUTOR

ASSEMBLY

REMOVE AND DISCARD

WHITE TEFLON® SEAL

(IF PRESENT)

A On fully cased coils, remove the coil access and plumbing panels.

B Remove any shipping clamps holding the liquid line and distributor as-

sembly.

C Using two wrenches, disconnect liquid line from liquid line orifice hous-

ing. Take care not to twist or damage distributor tubes during this pro-

cess.

D Remove and discard fixed orifice, valve stem assembly if present and

Teflon® washer as illustrated above.

E Use a field−provided fitting to temporary reconnect the liquid line to the

indoor unit’s liquid line orifice housing.

TYPICAL EXISTING FIXED ORIFICE

REMOVAL PROCEDURE (UNCASED

COIL SHOWN)

TYPICAL EXISTING EXPANSION VALVE REMOVAL

PROCEDURE (UNCASED COIL SHOWN)

TWO PIECE PATCH PLATE

(UNCASED COIL ONLY)

VAPOR

LINE

DISTRIBUTOR

ASSEMBLY

DISTRIBUTOR

TUBES

LIQUID

LINE

MALE EQUALIZER

LINE FITTING

EQUALIZER

LINE

CHECK

EXPANSION

VALVE

TEFLON®

RING

STUB END

TEFLON®

RING

SENSING BULB

LIQUID LINE

ORIFICE

HOUSING

LIQUID LINE

ASSEMBLY WITH

BRASS NUT

A On fully cased coils, remove the coil access and plumbing panels.

B Remove any shipping clamps holding the liquid line and distributor

assembly.

C Disconnect the equalizer line from the check expansion valve

equalizer line fitting on the vapor line.

D Remove the vapor line sensing bulb.

E Disconnect the liquid line from the check expansion valve at the liquid

line assembly.

F Disconnect the check expansion valve from the liquid line orifice

housing. Take care not to twist or damage distributor tubes during this

process.

G Remove and discard check expansion valve and the two Teflon® rings.

H Use a field−provided fitting to temporary reconnect the liquid line to the

indoor unit’s liquid line orifice housing.

LOW HIGH

EXISTING

INDOOR

UNIT

GAUGE

MANIFOLD

INVERTED HCFC−22

CYLINDER CONTAINS

CLEAN HCFC−22 TO BE

USED FOR FLUSHING.

LIQUID LINE SERVICE

VALVE

INLET

DISCHARGE

TANK

RETURN

CLOSED

OPENED

RECOVERY

CYLINDER

RECOVERY MACHINE

NEW

OUTDOOR

UNIT

VAPOR LINE

SERVICE VALVE

VAPOR

LIQUID

A Inverted HCFC−22 cylinder with clean refrigerant to the vapor service

valve.

B HCFC−22 gauge set (low side) to the liquid line valve.

C HCFC−22 gauge set center port to inlet on the recovery machine with an

empty recovery tank to the gauge set.

D Connect recovery tank to recovery machines per machine instructions.

CONNECT GAUGES AND EQUIPMENT FOR

FLUSHING PROCEDURE

FLUSHING LINE SET

A Set the recovery machine for liquid recovery and start the

recovery machine. Open the gauge set valves to allow the

recovery machine to pull a vacuum on the existing system line

set and indoor unit coil.

B Invert the cylinder of clean HCFC−22 and open its valve to allow

liquid refrigerant to flow into the system through the vapor line

valve. Allow the refrigerant to pass from the cylinder and through

the line set and the indoor unit coil before it enters the recovery

machine.

C After all of the liquid refrigerant has been recovered, switch the

recovery machine to vapor recovery so that all of the HCFC−22

vapor is recovered. Allow the recovery machine to pull down to 0

the system.

D Close the valve on the inverted HCFC−22 drum and the gauge

set valves. Pump the remaining refrigerant out of the recovery

machine and turn the machine off.

The line set and indoor unit coil must be flushed with at least the

same amount of clean refrigerant that previously charged the

system. Check the charge in the flushing cylinder before

proceeding.

Figure 10. Removing Indoor Refrigerate Metering Device and Flushing Procedures

Page 15

XP16 SERIES

Installing New Indoor Metering Device

This outdoor unit is designed for use in HFC−410A systems that use a check / expansion valve metering device (purchased

separately) at the indoor coil.

See the Lennox XP16 Engineering Handbook for approved check / expansion valve kit match−ups. The check / expansion

valve device can be installed either internal or external to the indoor coil. In applications where an uncased coil is being

installed in a field−provided plenum, install the check / expansion valve in a manner that will provide access for field servicing

of the check / expansion valve (see figure 11).

A Attach the vapor line sensing bulb in the proper

orientation as illustrated to the right using the clamp and

screws provided.

NOTE  Confirm proper thermal contact between vapor line

and expansion bulb before insulating the sensing bulb once

installed.

B Connect the equalizer line from the check / expansion

valve to the equalizer vapor port on the vapor line. Finger

tighten the flare nut plus 1/8 turn (7 ft−lbs) as illustrated

below.

TWO PIECE

PATCH PLATE

(UNCASED

COIL ONLY)

VAPOR

LINE

LIQUID LINE

ORIFICE

HOUSING

DISTRIBUTOR

TUBES

LIQUID LINE

MALE EQUALIZER LINE

FITTING (SEE

EQUALIZER LINE

INSTALLATION FOR

FURTHER DETAILS)

SENSING

LINE

EQUALIZER

LINE

CHECK /

EXPANSION

VALVE

TEFLON®

RING

(Uncased Coil Shown)

Sensing bulb insulation is

required if mounted external to

the coil casing.

STUB

END

TEFLON®

RING

LIQUID LINE

ASSEMBLY WITH

BRASS NUT

DISTRIBUTOR

ASSEMBLY

A Remove the field−provided fitting that temporarily

reconnected the liquid line to the indoor unit’s distributor

assembly.

B Install one of the provided Teflon® rings around the

stubbed end of the check / expansion valve and lightly

lubricate the connector threads and expose surface of

the Teflon® ring with refrigerant oil.

C Attach the stubbed end of the expansion valve to the

liquid line orifice housing. Finger tighten and use an

appropriately sized wrench to turn an additional 1/2 turn

clockwise as illustrated in the figure above, or 20 ft−lb.

D Place the remaining Teflon® washer around the other

end of the check / expansion valve. Lightly lubricate

connector threads and expose surface of the Teflon®

ring with refrigerant oil.

E Attach the liquid line assembly to the check / expansion

valve. Finger tighten and use an appropriately sized

wrench to turn an additional 1/2 turn clockwise as

illustrated in the figure above or 20 ft−lb.

ON 7/8" AND LARGER LINES,

MOUNT SENSING BULB AT

EITHER THE 4 OR 8 O’CLOCK

POSITION. NEVER MOUNT ON

BOTTOM OF LINE.

ON LINES SMALLER THAN

7/8", MOUNT SENSING

BULB AT EITHER THE 3 OR

9 O’CLOCK POSITION.

BULB

VAPOR LINE

NOTE  NEVER MOUNT ON BOTTOM OF LINE.

BULB

VAPOR LINE

FLARE NUT

COPPER FLARE

SEAL BONNET

MALE BRASS EQUALIZER

LINE FITTING

FLARE SEAL CAP

11 12

1/2 Turn

SENSING BULB INSTALLATION

EQUALIZER LINE INSTALLATION

11 12

1/8 Turn

Remove and discard either the flare seal cap or flare nut with

copper flare seal bonnet from the equalizer line port on the vapor

line as illustrated in the figure to the right.

INDOOR EXPANSION VALVE INSTALLATION

Figure 11. Installing Indoor Check / Expansion Valve

Page 16

Leak Test Line Set and Indoor Coil

IMPORTANT

Leak detector must be capable of sensing HFC refrigerant.

TO VAPOR

SERVICE VALVE

HFC−410A

MANIFOLD GAUGE SET

OUTDOOR UNIT

HIGHLOW

NITROGEN

A Connect an HFC−410A manifold gauge set high pressure hose to the

vapor valve service port.

NOTE  Normally, the high pressure hose is connected to the liquid

line port. However, connecting it to the vapor port better protects the

manifold gauge set from high pressure damage.

B With both manifold valves closed, connect the cylinder of HFC−410A

refrigerant to the center port of the manifold gauge set.

NOTE  Later in the procedure, the

HFC−410A container will be replaced by

the nitrogen container.

CONNECT GAUGE SET

Figure 12. Manifold Gauge Set Connections for Leak Testing

TEST FOR LEAKS

After the line set has been connected to the indoor and

outdoor units, check the line set connections and indoor

unit for leaks. Use the following procedure to test for leaks:

1. With both manifold valves closed, connect the cylinder

of HFC−410A refrigerant to the center port of the

manifold gauge set. Open the valve on the HFC−410A

cylinder (vapor only).

2. Open the high pressure side of the manifold to allow

HFC−410A into the line set and indoor unit. Weigh in

a trace amount of HFC−410A. [A trace amount is a

maximum of two ounces (57 g) refrigerant or three

pounds (31 kPa) pressure]. Close the valve on the

HFC−410A cylinder and the valve on the high pressure

side of the manifold gauge set. Disconnect the

HFC−410A cylinder.

3. Connect a cylinder of dry nitrogen with a pressure

regulating valve to the center port of the manifold

gauge set.

4. Adjust dry nitrogen pressure to 150 psig (1034 kPa).

Open the valve on the high side of the manifold gauge

set in order to pressurize the line set and the indoor unit.

5. After a few minutes, open one of the service valve

ports and verify that the refrigerant added to the

system earlier is measurable with a leak detector.

6. After leak testing disconnect gauges from service

ports.

Page 17

XP16 SERIES

Evacuating Line Set and Indoor Coil

Evacuating the system of non−condensables is critical for proper operation of the unit. Non−condensables are defined as any

gas that will not condense under temperatures and pressures present during operation of an air conditioning system.

Non−condensables and water suction combine with refrigerant to produce substances that corrode copper piping and

compressor parts.

A Open both manifold valves and start the vacuum pump.

B Evacuate the line set and indoor unit to an absolute pressure of 23,000 microns (29.01 inches of mercury).

NOTE  During the early stages of evacuation, it is desirable to close the manifold gauge valve at least once. A rapid rise in pressure

indicates a relatively large leak. If this occurs, repeat the leak testing procedure.

NOTE  The term absolute pressure means the total actual pressure within a given volume or system, above the absolute zero of

pressure. Absolute pressure in a vacuum is equal to atmospheric pressure minus vacuum pressure.

C When the absolute pressure reaches 23,000 microns (29.01 inches of mercury), perform the following:

SClose manifold gauge valves

SClose valve on vacuum pump and turn off vacuum pump

SDisconnect manifold gauge center port hose from vacuum pump

SAttach manifold center port hose to a dry nitrogen cylinder with pressure regulator set to 150 psig (1034 kPa) and purge the hose.

SOpen manifold gauge valves to break the vacuum in the line set and indoor unit.

SClose manifold gauge valves.

D Shut off the dry nitrogen cylinder and remove the manifold gauge hose from the cylinder. Open the manifold gauge valves to release the

dry nitrogen from the line set and indoor unit.

E Reconnect the manifold gauge to the vacuum pump, turn the pump on, and continue to evacuate the line set and indoor unit until the

absolute pressure does not rise above 500 microns (29.9 inches of mercury) within a 20−minute period after shutting off the vacuum pump

and closing the manifold gauge valves.

F When the absolute pressure requirement above has been met, disconnect the manifold hose from the vacuum pump and connect it to an

upright cylinder of HFC−410A refrigerant. Open the manifold gauge valve 1 to 2 psig in order to release the vacuum in the line set and

indoor unit.

G Perform the following:

OUTDOOR

UNIT

TO VAPOR

SERVICE VALVE

TO LIQUID LINE

SERVICE VALVE

MICRON

GAUGE

VACUUM PUMP

A34000 1/4 SAE TEE WITH

SWIVEL COUPLER

500

MANIFOLD

GAUGE SET

HFC−410A

RECOMMEND

MINIMUM 3/8" HOSE

AConnect low side of manifold gauge set

with 1/4 SAE in−line tee to vapor line

service valve

BConnect high side of manifold gauge

set to liquid line service valve

CConnect micron gauge available

connector on the 1/4 SAE in−line tee.

DConnect the vacuum pump (with

vacuum gauge) to the center port of the

manifold gauge set. The center port

line will be used later for both the

HFC−410A and nitrogen containers.

HIGHLOW

11 12

1/6 TURN

NITROGEN

1CONNECT GAUGE SET

2EVACUATE THE SYSTEM

NOTE  Remove cores from service valves (if not already done).

SClose manifold gauge valves.

SShut off HFC−410A cylinder.

SReinstall service valve cores by removing manifold hose from service valve. Quickly install cores with core

tool while maintaining a positive system pressure.

SReplace stem caps and secure finger tight, then tighten an additional one−sixth (1/6) of a turn as illustrated.

Figure 13. Evacuating Line Set and Indoor Coil

Page 18

IMPORTANT

Use a thermocouple or thermistor electronic vacuum

gauge that is calibrated in microns. Use an instrument

capable of accurately measuring down to 50 microns.

WARNING

Danger of Equipment Damage. Avoid deep vacuum

operation. Do not use compressors to evacuate a

system. Extremely low vacuums can cause internal

arcing and compressor failure. Damage caused by

deep vacuum operation will void warranty.

Electrical Connections

In the U.S.A., wiring must conform with current local codes

and the current National Electric Code (NEC). In Canada,

wiring must conform with current local codes and the current

Canadian Electrical Code (CEC).

Refer to the furnace or air handler installation instructions

for additional wiring application diagrams and refer to unit

nameplate for minimum circuit ampacity and maximum

overcurrent protection size.

24VAC TRANSFORMER

Use the transformer provided with the furnace or air

handler for low-voltage control power (24VAC − 40 VA

minimum)

Refer to the unit nameplate for minimum circuit ampacity, and

maximum fuse or circuit breaker (HACR per NEC). Install power

wiring and properly sized disconnect switch.

NOTE  Units are approved for use only with copper conductors.

Ground unit at disconnect switch or to an earth ground.

SIZE CIRCUIT AND INSTALL DISCONNECT

SWITCH

NOTE  24VAC, Class II circuit connections are made in the control

panel.

Install room thermostat (ordered separately) on an inside wall

approximately in the center of the conditioned area and 5 feet

(1.5m) from the floor. It should not be installed on an outside wall

or where it can be affected by sunlight or drafts.

THERMOSTAT

5 FEET

(1.5M)

INSTALL THERMOSTAT

DISCONNECT

SWITCH

MAIN FUSE BOX/

BREAKER PANEL

WARNING

Electric Shock Hazard. Can cause injury or death. Unit must be grounded in accordance with national and

local codes.

Line voltage is present at all components when unit is not in operation on units with single-pole contactors.

Disconnect all remote electric power supplies before opening access panel. Unit may have multiple power

supplies.

Page 19

XP16 SERIES

ARun 24VAC control wires through cutout with grommet.

BRun 24VAC control wires through wire tie.

CMake 24VAC control wire connections.

DTighten wire tie to security 24V control wiring.

HIGH VOLTAGE FIELD WIRING

LOW VOLTAGE (24V) FIELD WIRING

CUTOUT WITH

GROMMET

NOTE − For proper voltages, select thermostat wire (control wires)

gauge per table above.

WIRE RUN LENGTH AWG# INSULATION TYPE

LESS THAN 100’ (30 METERS) 18 TEMPERATURE RATING

MORE THAN 100’ (30 METERS) 16 35ºC MINIMUM.

24V CONTROL WIRES TIGHTEN WIRE TIE

LOW VOLTAGE CONNECTIONS

NOTE − Do not bundle any excess 24VAC control wires inside

control box.

NOTE − Wire tie provides low voltage wire strain relief and to maintain

separation of field installed low and high voltage circuits.

Install low voltage wiring from outdoor to indoor unit and from thermostat to indoor unit as illustrated. See figures 14 and 15 for typical field

connections when connecting unit to either a CBX32MV or CBX40UHV in non−communicating mode. For connections to other Lennox air handlers

or furnaces, see the ComfortSense® 7000 installation instruction for further match component wiring illustrations.

NOTE − Any excess high voltage field wiring

should be trimmed and secured away from

any low voltage field wiring.

GROUND

NOTE − To facilitate a conduit, a cutout is lo-

cated in the bottom of the control box. Connect

conduit to the control box using a proper con-

duit fitting.

CONDUIT

CUTOUT

OUTDOOR UNIT

CONTROL BOX

HIGH VOLTAGE POWER SUPPLY CONNECTIONS

Page 20

CBX32MV

CBX40UHV

HEAT PUMP UNIT

(TWO−STAGE) X2658 OUTDOOR SENSOR IS REQUIRED FOR OUTDOOR

TEMPERATURE DISPLAY, DEW POINT CONTROL, HEAT PUMP AND

DUAL FUEL BALANCE POINTS.

COMFORTSENSET

7000

RRR

W3 H

W1 W1 W1

Y2Y2

CCC

O. D.

SENSOR

(X2658)

OUT

CUT ON−BOARD LINK R −O.

CUT ON−BOARD LINK R−DS WHEN DEHUMIDIFICATION TERMINAL IS USED.

CUT ON−BOARD LINK Y1−Y2 FOR TWO−STAGE HP

3FIELD PROVIDED JUMPER BETWEEN Y2 OUT BL ON HEAT PUMP

TO Y2 ON CBX40UHV.

CONNECTED ON UNIT WITH LSOM. RESISTOR KIT (CAT # 47W97)

IS REQUIRED WHEN CONNECTING THE COMFORTSENSE 7000

WITH THE LSOM 2.

Y1−Y2

2−STAGE

COMPR

R−O

HEAT

PUMP

R−DS

DEHUM

HARMONY

CUT FOR OPTION

AIR

HANDLER

CONTROL

IMPORTANT − USE CARE WHEN CUTTING LINKS TO

PREVENT DAMAGE TO CONTROL. SEE CBX40UHV

INSTALLATION INSTRUCTION FOR FURTHER DETAILS.

Figure 14. Typical Field Wiring  Heat Pump Application with CBX32MV or CBX40UHV

YELLOW

BLUE (NOT REQUIRED FOR SINGLE STAGE)

RED

BLACK

PURPLE

BLACK

BLUE

RED

FAN RELAY (NOT REQUIRED

WITH SINGLE−SPEED

OUTDOOR FAN)

OUTDOOR

SENSOR

(X2658)

COMFORTSENSEt

7000 THERMOSTAT

OUTDOOR UNIT

CUT ON−BOARD LINK R −O.

CUT ON−BOARD LINK Y1−Y2 FOR TWO−STAGE A/C ONLY

CUT ON−BOARD LINK R−DS WHEN DEHUMIDIFICATION

TERMINAL IS USED.

BROWN (NOT USED FOR APPLICATIONS WITHOUT LSOM

Y1−Y2

2−STAGE

COMPR

R−O

HEAT

PUMP

R−DS

DEHUM

HARMONY

CUT FOR OPTION

RESISTOR KIT (CAT # 47W97) IS REQUIRED

WHEN CONNECTING THE COMFORTSENSE

7000 WITH THE LSOM 2.

IMPORTANT − USE CARE WHEN CUTTING LINKS TO

PREVENT DAMAGE TO CONTROL. SEE CBX40UHV

INSTALLATION INSTRUCTION FOR FURTHER DETAILS.

CBX32MV OR

CBX40UHV

AIR

HANDLER

CONTROL

Figure 15. Heat Pump Application  Humiditrol ® and Second−Stage Outdoor Fan Relay Wiring with

CBX32MV or CBX40UHV

Page 21

XP16 SERIES

Figure 16. Typical Unit Wiring Diagram (−024, −036 and −048 Only)

Page 22

Figure 17. Typical Unit Wiring Diagram (−060 Only)

Page 23

XP16 SERIES

Figure 18. Typical Factory Wiring Diagram (No Field Modifications)

Unit Start−Up

IMPORTANT

If unit is equipped with a crankcase heater, it should be

energized 24 hours before unit start−up to prevent

compressor damage as a result of slugging.

UNIT START−UP

1. Rotate fan to check for binding.

2. Inspect all factory− and field−installed wiring for loose

connections.

3. Verify that the manifold gauge set is connected as

illustrated in figure 21. Use a temperature sensor

positioned near the liquid line service port as illustrated

in figure 21 which will be required later when using the

subcooling method for optimizing the system

refrigerant charge.

4. Replace the stem caps and tighten to the value listed

in table 1.

5. Check voltage supply at the disconnect switch. The

voltage must be within the range listed on the unit’s

nameplate. If not, do not start the equipment until you

have consulted with the power company and the

voltage condition has been corrected.

6. Open both the liquid and vapor line service valves to

release the refrigerant charge contained in outdoor

unit into the system.

7. Use figure 19 to determine next step in system

preparation.

REFRIGERANT

PRESENT

OPEN BOTH VAPOR AND LIQUID SERVICE

VALVE STEMS TO RELEASE

REFRIGERANT FROM OUTDOOR UNIT TO

SYSTEM.

YESNO

GO TO SERVICE AND WEIGH

IN REFRIGERANT CHARGE

FOR OUTDOOR UNITS

DELIVERED VOID OF CHARGE

ON PAGE 24.

GO TO OPTIMIZING SYSTEM

REFRIGERANT CHARGE ON

PAGE 26.

Figure 19. Outdoor Unit Factory Charge

Page 24

Service and Weigh In Refrigerant for Outdoor Units Delivered Void of Charge

The following procedures are only required if it has been determine that the new outdoor unit is void of charge. Skip to the

next section if refrigerant charge is present.

LEAK CHECK, REPAIR AND EVACUATE

If the outdoor unit is void of refrigerant, clean the system

using the procedure described below.

1. Leak check system using procedures provided on

page 16. Repair any leaks discovered during leak test.

2. Evacuate the system using procedure provided in

figure 13.

3. Use nitrogen to break the vacuum and install a new

filter drier in the system.

4. Evacuate the system again using procedure in figure

12.

CONNECT MANIFOLD GAUGE SET AND WEIGH IN

CHARGE

After the evacuation procedure, reconnect the manifold

gauge set as illustrated in figure 21.

NOTE − Temperature sensor illustrated in figure 21 is not

required for initial system weigh in charging.

1. Close manifold gauge set valves and connect the

center hose to a cylinder of HFC−410A. Set for liquid

phase charging.

2. Connect the manifold gauge set’s low pressure side to

the true suction port.

3. Connect the manifold gauge set’s high pressure side

to the liquid line service port.

4. Connect the center hose of the gauge set to a cylinder

of HFC−410A and purge the hose. Then, place the

cylinder upside down on a scale.

5. Check that fan rotates freely.

6. Inspect all factory− and field−installed wiring for loose

connections.

7. Open the high side manifold gauge valve and weigh in

liquid refrigerant. Use figure 20 in calculating the

correct weigh−in charge.

8. Close manifold gauge valves.

9. Monitor the system to determine the amount of

moisture remaining in the oil. It may be necessary to

replace the bi−flow filter drier several times to achieve

the required dryness level. If system dryness is not

verified, the compressor will fail in the future.

10. Continue to Optimizing System Refrigerant Charge

on page 26 to optimize the system charge using

subcooling method.

WEIGH−IN CHARGING

LIQUID LINE SET DIAMETER OUNCES PER 5 FEET (G PER 1.5 M) ADJUST FROM 15 FEET

(4.6 M) LINE SET*

3/8" (9.5 MM) 3 OUNCE PER 5’ (85 G PER 1.5 M)

*If line length is greater than 15 ft. (4.6 m), add this amount. If line length is less than 15 ft. (4.6 m), subtract

this amount.

Refrigerant Charge per Line Set Length

NOTE  The above nameplate is for illustration purposes only. Go to actual nameplate on outdoor unit for charge information.

NOTE  Insulate liquid line when it is routed through areas where the surrounding ambient temperature could become higher than the temperature

of the liquid line or when pressure drop is equal to or greater than 20 psig.

CALCULATING SYSTEM CHARGE FOR OUTDOOR UNIT VOID OF CHARGE

If the system is void of refrigerant, first, locate and repair any leaks and then weigh in the refrigerant charge into the unit. To calculate the total

refrigerant charge:

Amount specified on

nameplate

Adjust amount. for variation in line set

length listed on line set length table below.

Additional charge specified per indoor

unit match listed on page 28. Total Charge

++=

Figure 20. Using HFC−410A Weigh In Method

Page 25

XP16 SERIES

TO LIQUID

LINE SERVICE

VALVE

TEMPERATURE SENSOR (USE FOR

SUBCOOLING METHOD)

DIGITAL SCALE

REFRIGERANT

TANK

TEMPERATURE SENSOR

(LIQUID LINE)

MANIFOLD GAUGE SET

AClose manifold gauge set valves and connect the center hose to a cylinder of HFC−410A. Set for liquid phase charging.

BConnect the manifold gauge set’s low pressure side to the true suction port.

CConnect the manifold gauge set’s high pressure side to the liquid line service port.

DPosition temperature sensor on liquid line near liquid line service port (use only for subcooling method).

OUTDOOR UNIT

CHARGE IN

LIQUID PHASE

CONNECTIONS FOR OPTIMIZING SYSTEM CHARGE

GAUGE SET

LOW HIGH

INSIDE OUTDOOR UNIT

TRUE SUCTION PORT

CONNECTION

NOTE  Refrigerant tank should be

turned right−side−up to deliver vapor

during charge optimizing procedure.

Figure 21. Gauge Set Connections for Adding Refrigerant

NOTE − Use gauge ports on vapor line valve and liquid valve for evacuating refrigerant lines and

indoor coil. Use true suction port to measure vapor pressure during charging.

OUTDOOR

COIL

CHECK / EXPANSION

VALVE

BI−FLOW FILTER / DRIER

COMPRESSOR

REVERSING VALVE

MUFFLER

NOTE − ARROWS INDICATE DIRECTION

OF REFRIGERANT FLOW

SERVICE

PORT

VAPOR

CHECK / EXPANSION VALVE

INDOOR UNIT

OUTDOOR UNIT

LIQUID LINE

SERVICE PORT

DISTRIBUTOR

INDOOR

COIL

TRUE SUCTION

PORT

Figure 22. Heat Pump Cooling Cycle

Page 26

Optimizing System Refrigerant Charge

This section provides instructions on optimizing the

system charge. This section includes:

SOptimizing procedure

SAdjusting indoor airflow

SUsing subcooling method

SApproved matched components, targeted subcooling

(SC) values and add charge values

SNormal operating pressures

STemperature pressures

OPTIMIZING PROCEDURE

1. Move the low−side manifold gauge hose from the

vapor line service valve to the true suction port (see

figure 21).

2. Set the thermostat for either cooling or heating

demand. Turn on power to the indoor unit and close

the outdoor unit disconnect switch to start the unit.

3. Allow unit to run for five minutes to allow pressures to

stabilize.

4. Check the airflow as instructed under Adjusting Indoor

Airflow to verify or adjust indoor airflow for maximum

efficiency. Make any air flow adjustments before

continuing with the optimizing procedure.

5. Use subcooling method to optimize the system

charge (see figure 24). Adjust charge as necessary.

ADJUSTING INDOOR AIRFLOW

Heating Mode Indoor Airflow Check

(Only use when indoor unit has electric heat)

Indoor blower airflow (CFM) may be calculated by

energizing electric heat and measuring:

STemperature rise between the return air and supply air

temperatures at the indoor coil blower unit,

SMeasuring voltage supplied to the unit,

SMeasuring amperage being drawn by the heat unit(s).

Then, apply the measurements taken in the following

formula to determine CFM:

CFM =

Amps x Volts x 3.41

1.08 x Temperature rise (F)

Cooling Mode Indoor Airflow Check

Check airflow using the Delta−T (DT) process using figure

23.

1. Determine the desired DTMeasure entering air temper-

ature using dry bulb (A) and wet bulb (B). DT is the intersect-

ing value of A and B in the table (see triangle).

2. Find temperature drop across coilMeasure the coil’s dry

bulb entering and leaving air temperatures (A and C). Tem-

perature Drop Formula: (TDrop) = A minus C.

3. Determine if fan needs adjustmentIf the difference between

the measured TDrop and the desired DT (TDrop–DT) is within

+3º, no adjustment is needed. See examples: Assume DT =

15 and A temp. = 72º, these C temperatures would necessi-

tate stated actions:

Cº T

Drop –DT=ºF ACTION

53º 19 – 15 =4Increase the airflow

58º 14 – 15 =−1 (within +3º range) no change

62º 10 – 15 =−5 Decrease the airflow

4. Adjust the fan speedSee indoor unit instructions to in-

crease/decrease fan speed.

Changing air flow affects all temperatures; recheck tempera-

tures to confirm that the temperature drop and DT are within

+3º.

80 24 24 24 23 23 22 22 22 20 19 18 17 16 15

78 23 23 23 22 22 21 21 20 19 18 17 16 15 14

76 22 22 22 21 21 20 19 19 18 17 16 15 14 13

74 21 21 21 20 19 19 18 17 16 16 15 14 13 12

72 20 20 19 18 17 17 16 15 15 14 13 12 11 10

70 19 19 18 18 17 17 16 15 15 14 13 12 11 10

57 58 59 60 61 62 63 64 65 66 67 68 69 70

Temp.

of air

entering

indoor

coil ºF

INDOOR

COIL

DRY

BULB

DRY

BULB

WET

BULB

TDrop

19º

Dry−bulb

Wet−bulb ºF

72º

64º

53º

air flowair flow

All temperatures are

expressed in ºF

ADJUSTING INDOOR AIRFLOW

Figure 23. Checking Airflow over Indoor Coil Using Delta−T Formula

Page 27

XP16 SERIES

1. Check liquid and vapor line pressures. Compare pressures with either second−stage

heat or cooling mode normal operating pressures listed in table 7. Table 7 is a general

guide and expect minor pressures variations. Significant pressure differences may

indicate improper charge or other system problem.

2. Decide whether to use cooling or heating mode based on current outdoor ambient

temperature:

AUse COOLING MODE when:

SOutdoor ambient temperature is 60°F (15.5°C) and above.

SIndoor return air temperature range is between 70 to 80°F (21−27°C). This

temperature range is what the target subcooling values are base upon in

tables 3 through 6.

If indoor return air temperature is not within reference range, set thermostat to

cooling mode and a setpoint of 68ºF (20ºC). This should place the outdoor unit

into second−stage (high−capacity) cooling mode. When operating and

temperature pressures have stabilized, continue to step 3.

BUse HEATING MODE when:

SOutdoor ambient temperature is 59°F (15.0°C) and below.

SIndoor return air temperature range is between 65−75°F (18−24°C). This

temperature range is what the target subcooling values are base upon in

tables 3 through 6.

If indoor return air temperature is not within reference range, set thermostat to

heating mode and a setpoint of 77ºF (25ºC). This should place the outdoor unit

into second−stage (high−capacity) heating mode. When operating and

temperature pressures have stabilized, continue to step 3.

3. Read the liquid line pressure; then find its corresponding temperature pressure listed

in table 8 and record it in the SATº space to the left.

4. Read the liquid line temperature; record in the LIQº space to the left.

5. Subtract LIQº temperature from SATº temperature to determine subcooling; record

it in SCº space to the left..

6. Compare SCº results with tables 3 through 6 (either Heating or Cooling mode

column), also consider any additional charge required for line set lengths longer than

15 feet and/or unit matched component combinations (Add Charge column).

7. If subcooling value is:

AGREATER than shown for the applicable unit match component, REMOVE

refrigerant;

BLESS than shown for the applicable unit match component, ADD refrigerant.

8. If refrigerant is added or removed, repeat steps 3 through 6 to verify charge.

9. Close all manifold gauge set valves and disconnect gauge set from outdoor unit.

10. Replace the stem and service port caps and tighten as specified in Operating Service

Valves on page 2.

11. Recheck voltage while the unit is running. Power must be within range shown on the

nameplate.

USE

COOLING

MODE

USE

HEATING

MODE

60ºF

(15ºC)

SATº

LIQº –

SCº =

OPTIMIZE CHARGE USING SUBCOOLING METHOD

Figure 24. Using HFC−410A Subcooling Method  Second Stage (High Capacity)

Page 28

APPROVED MATCHED SYSTEM COMPONENTS, TARGETED SUBCOOLING (SC) VALUES AND

ADD CHARGE VALUES

Listed below are the approved matched system components (air handlers and indoor coils), targeted subcooling and

add charge values for the XP16. This information is also listed on the unit charging sticker located on the outdoor unit

access panel.

Subcooling values listed in the following tables are based

on outdoor ambient air temperature of:

S60°F (15.5°C) and above for cooling mode

S59°F (15.0°C) and below for heating mode.

Table 3. XP16−024−230

Indoor Air Handers

and Coils

Heating

Mode

+5ºF

Cooling

Mode

+1ºF

*Add Charge

Subcooling lb. oz.

CBX26UH−024 45 6 0 15

CBX27UH−024−230 20 7 0 9

CBX27UH−030−230 17 7 1 3

CBX32MV−024/030 20 7 0 9

CBX32MV−036 17 7 1 3

CBX40UHV−024 17 7 1 3

CBX40UHV−030 17 7 1 3

CBX40UHV−036 17 7 1 3

CH33−31B 31 8 1 12

CR33−30/36A/B/C 45 4 0 0

CX34−31A/B 24 7 1 11

CX34−38A/B 18 8 1 10

Table 4. XP16−036−230

Indoor Air Handers

and Coils

Heating

Mode

+5ºF

Cooling

Mode

+1ºF

*Add Charge

Subcooling lbs. oz.

CBX26UH−036 50 5 0 0

CBX27UH−036−230 22 7 0 9

CBX27UH−042−230 24 11 3 0

CBX32M−036 22 7 0 9

CBX32MV−036 22 7 0 9

CBX32MV−048 24 11 3 0

CBX40UHV−030 22 7 0 9

CBX40UHV−036 22 7 0 9

CBX40UHV−042 24 11 3 0

CBX40UHV−048 24 11 3 0

CH33−43B 13 10 2 7

CH33−48C 37 11 211

CH33−43C 37 11 211

CR33−48B/C 49 7 0 9

CX34−43B/C 29 9 2 11

CX34−50/60C 29 9 2 11

Table 5. XP16−048−230

Indoor Air Handers

and Coils

Heating

Mode

+5ºF

Cooling

Mode

+1ºF

*Add Charge

Subcooling lbs. oz.

CBX26UH−048−230 10 8 1 4

CBX27UH−048−230 19 9 1 4

CBX27UH−060−230 13 14 3 3

CBX32M−048 19 9 1 4

CBX32M−060 14 9 1 11

CBX32MV−048 19 9 1 4

CBX32MV−060 14 9 1 11

CBX32MV−068 9 8 1 11

CBX40UHV−048 19 9 1 4

CBX40UHV−060 14 9 1 11

CH23−68 24 10 1 12

CH33−49C 19 9 2 5

CH33−50/60C 19 9 2 5

CH33−60D 13 8 0 0

CH33−62D 11 9 1 4

CR33−50/60C 15 7 0 10

CR33−60D 15 7 0 10

CX34−60D 14 8 1 0

CX34−62D 9 9 1 6

CX34−62C 8 9 1 9

Table 6. XP16−060−230

Indoor Air Handers

and Coils

Heating

Mode

+5ºF

Cooling

Mode

+1ºF

*Add Charge

Subcooling lbs. oz.

CBX26UH−060 20 9 4 13

CBX27UH−060−230 10 6 2 3

CBX32M−060 17 6 1 12

CBX32MV−060 17 6 1 12

CBX32MV−068 15 7 2 1

CBX40UHV−060 17 6 1 12

CH23−682 37 9 2 10

CH33−50/60C 33 8 1 0

CH33−62D 15 7 1 4

CR33−50/60C 24 7 0 0

CR33−60D 24 7 0 0

CX34−62C 21 9 2 16

CX34−62D 13 7 1 4

*Amount of charge required in additional to charge shown on unit

nameplate. (Remember to consider line set length difference.)

Page 29

XP16 SERIES

NORMAL OPERATING PRESSURES

Use the following tables to perform maintenance checks; it

is not a procedure for charging the system. Minor

variations in these pressures may be due to differences in

installations. Significant deviations could mean that the

system is not properly charged or that a problem exists

with some component in the system.

Typical pressures only, expressed in psig (liquid +/− 10

and vapor +/− 5 psig); matched indoor component (air

handler or coil), indoor air quality, and indoor load will

cause the pressures to vary.

Table 7. Normal Operating Pressures*

Normal Operating Pressures − Cooling

XP16 −024 −036 −048 −060

F

(C)** Liq Vap Liq Vap Liq Vap Liq Vap

First Stage (Low Capacity) Pressure

(18.3) 226 144 220 141 224 143 230 137

(23.9) 260 145 254 144 259 143 267 139

(29.4) 301 148 295 148 302 147 311 141

(35.0) 346 151 340 150 346 149 357 144

105

(40.6) 396 153 389 153 396 152 398 147

115

(46.1) 451 156 444 156 450 155 453 149

Second Stage (High Capacity) Pressure

(18.3) 241 140 232 129 238 138 232 131

(23.9) 279 142 269 136 278 140 276 133

(29.4) 321 144 312 140 321 142 320 136

(35.0) 369 146 346 142 372 144 367 138

105

(40.6) 421 148 409 145 424 147 421 141

115

(46.1) 480 151 465 148 481 149 479 144

Normal Operating Pressures − Heating

First Stage (Low Capacity) Pressure

(10) 312 112 350 115 336 114 385 108

(15.5) 330 130 372 136 363 135 414 126

Second Stage (High Capacity) Pressure

(−7.0) 299 64 321 61 289 57 332 59

(−1.0) 312 79 347 74 294 69 349 67

(4.4) 325 93 367 90 321 80 361 75

(10) 344 110 387 110 341 110 383 85

(15.5) 358 128 395 131 361 128 425 122

** Temperature of air entering outdoor coil.

TEMPERATURE PRESSURES

Compute subcooling by determining saturated

condensing temperature from temperature pressure

chart. Subtract from liquid temperature entering TXV.

Table 8. HFC−410A Temperature (°F) −

Pressure (Psig)

°F Psig °F Psig °F Psig °F Psig

32 100.8 63 178.5 94 290.8 125 445.9

33 102.9 64 181.6 95 295.1 126 451.8

34 105.0 65 184.3 96 299.4 127 457.6

35 107.1 66 187.7 97 303.8 128 463.5

36 109.2 67 190.9 98 308.2 129 469.5

37 111.4 68 194.1 99 312.7 130 475.6

38 113.6 69 197.3 100 317.2 131 481.6

39 115.8 70 200.6 101 321.8 132 487.8

40 118.0 71 203.9 102 326.4 133 494.0

41 120.3 72 207.2 103 331.0 134 500.2

42 122.6 73 210.6 104 335.7 135 506.5

43 125.0 74 214.0 105 340.5 136 512.9

44 127.3 75 217.4 106 345.3 137 519.3

45 129.7 76 220.9 107 350.1 138 525.8

46 132.2 77 224.4 108 355.0 139 532.4

47 134.6 78 228.0 109 360.0 140 539.0

48 137.1 79 231.6 110 365.0 141 545.6

49 139.6 80 235.3 111 370.0 142 552.3

50 142.2 81 239.0 112 375.1 143 559.1

51 144.8 82 242.7 113 380.2 144 565.9

52 147.4 83 246.5 114 385.4 145 572.8

53 150.1 84 250.3 115 390.7 146 579.8

54 152.8 85 254.1 116 396.0 147 586.8

55 155.5 86 258.0 117 401.3 148 593.8

56 158.2 87 262.0 118 406.7 149 601.0

57 161.0 88 266.0 119 412.2 150 608.1

58 163.9 89 270.0 120 417.7 151 615.4

59 166.7 90 274.1 121 423.2 152 622.7

60 169.6 91 278.2 122 428.8 153 630.1

61 172.6 92 282.3 123 434.5 154 637.5

62 175.4 93 286.5 124 440.2 155 645.0

Page 30

System Operation

IMPORTANT

Some scroll compressor have internal vacuum protector

that will unload scrolls when suction pressure goes

below 20 psig. A hissing sound will be heard when the

compressor is running unloaded. Protector will reset

when low pressure in system is raised above 40 psig. DO

NOT REPLACE COMPRESSOR.

This section addresses:

SUnit components (sensors, temperature switch,

pressure switches and demand defrost control)

SSecond−stage operation

UNIT COMPONENTS

Demand Defrost Control (A108)

The demand defrost control measures differential

temperatures to detect when the system is performing

poorly because of ice build−up on the outdoor coil. The

controller self−calibrates when the defrost system starts

and after each system defrost cycle. The demand defrost

control’s: components are shown in figure 25.

SDemand defrost control connections, jumpers and

LED locations are shown in figure 25.

SDemand defrost control connections, jumpers and

LED descriptions are listed on table 9.

SDemand defrost control status, fault and lockout LEDs

are listed in table 10.

24V TERMINAL STRIP

CONNECTIONS (P2)

DIAGNOSTIC LEDS

(DS1 AND DS2)

PRESSURE SWITCH

CIRCUIT

CONNECTIONS

TEST PINS (P1)

Note − Component locations vary by board manufacturer.

SENSOR PLUG IN

(COIL AND

AMBIENT

SENSORS) (P4)

REVERSING VALVE

(O OUT)

DELAY PINS

(P5)

LOW AMBIENT

THERMOSTAT PINS

(P3)

DEFROST TERMINATION

PIN SETTINGS (P1)

Figure 25. Demand Defrost Control (A108)

Page 31

XP16 SERIES

Table 9. Demand Defrost Control (A108) Inputs, Outputs and Configurable Settings

Control

Locations

Control Label or

Description Purpose Function

P1 TEST Test Mode See Test Mode on page 39 for further details.

P1 50, 70, 90, 100

Defrost Temperature

Termination Shunt (Jumper)

Pins

The demand defrost control as illustrated in figure 25 has valid selections

which are: 50, 70, 90, and 100°F (10, 21, 32 and 38°C). The shunt

termination pin is factory set at 50°F (10°C). If the temperature shunt is

not installed, the default termination temperature is 90°F (32°C).

W1 24VAC Thermostat Input /

Output 24VAC input / output from indoor thermostat to indoor unit.

C24VAC Common 24VAC common

LThermostat Service Light Thermostat service light connection.

R 24VAC 24VAC

Y2 Thermostat Input Controls the second stage operation of the unit.

OThermostat Input Reversing valve solenoid.

Y1 Thermostat Input Controls the operation of the unit.

P3 55, 50, 45, 40 Low Ambient Thermostat

Pins

Provides selection of the Y2 compressor lock−in temperature. Valid

options are 40, 45, 50 and 55 degrees Fahrenheit.

DIS−YEL Coil Sensor (P4−5) Ground connection for outdoor coil temperature sensor.

(P4−6) Connection for outdoor coil temperature sensor.

AMB−BLACK Ambient Sensor (P4−3) Ground connection for outdoor ambient temperature sensor.

(P4−4) Connection for outdoor ambient temperature sensor.

COIL−BROWN Discharge Sensor No discharge sensor is used; replaced by 10K resistor.

P5 DELAY Delay Mode

The demand defrost control has a field−selectable function to reduce

occasional sounds that may occur while the unit is cycling in and out of

the defrost mode. When a jumper is installed on the DELAY pins, the

compressor will be cycled off for 30 seconds going in and out of the

defrost mode. Units are shipped with jumper installed on DELAY pins.

NOTE − The 30 second off cycle is NOT functional when TEST pins on

P1 are jumpered.

P6 TST, PS DF, C, R, O, Y1, Y2 Factory Test Connectors No field use.

DS1 RED LED

Diagnostic LED

Valid states for demand defrost control two LEDs are OFF, ON and

FLASHING which indicate diagnostics conditions that are described in

table 10.

DS2 GREEN LED

FAN TWO CONNECTORS Condenser Fan Operation These two connections provide power for the condenser fan.

O OUT O OUT 24 VAC output 24 VAC output connection for reversing valve.

LO−PS LO−PS Low−Pressure Switch

When the low pressure switch trips, the demand defrost control will cycle

off the compressor, and the strike counter in the demand defrost control

will count one strike. The low pressure switch is ignored under the

following conditions:

Sduring the defrost cycle and 90 seconds after the termination of

defrost

Swhen the average ambient sensor temperature is below 0°F (−18°C)

Sfor 90 seconds following the start up of the compressor

Sduring TEST mode

Y2 OUT Y2 OUT 24 VAC Output 24 VAC output for second stage compressor solenoid.

Y1 OUT Y1 OUT 24 VAC Common Output 24 VAC common output, switched for enabling compressor contactor.

HS−PS HS−PS High−Pressure Switch

When the high pressure switch trips, the demand defrost control will cycle

off the compressor, and the strike counter in the demand defrost control

will count one strike.

L L Service Light Output 24VAC service light output.

24V 24V 24 Volt output 24VAC typically used to supply power to the Lennox System Operation

Monitor (LSOM). Not used in this system.

Page 32

DEMAND DEFROST CONTROL (A108) DIAGNOSTIC LEDS

The state (Off, On, Flashing) of two LEDs on the demand defrost control (DS1 [Red] and DS2 [Green]) indicate diagnostics

conditions that are described in table 10.

Table 10. Demand Defrost Control (A108) Diagnostic LEDs

DS1 and DS2 System Status, Fault and Lockout Codes

DS2

Green

DS1

Red Type Condition/Code Possible Cause(s) Solution

OFF OFF Status Power problem

No power (24V) to demand

defrost control terminals R and C

or demand defrost control failure.

1Check control transformer power (24V).

2If power is available to demand defrost con-

trol and LED(s) do not light, replace demand

defrost control.

Simultaneous

SLOW Flash Status Normal operation Unit operating normally or in

standby mode. None required.

Alternating SLOW

Flash Status 5−minute anti−short cycle delay Initial power up, safety trip, end of

room thermostat demand. None required (jumper TEST pins to override)

Simultaneous

FAST Flash Fault Ambient Sensor Problem

Sensor being detected open or shorted or out of temperature range. Demand defrost

control will revert to time/temperature defrost operation. (System will still heat or

cool).

Alternating

FAST Flash Fault Coil Sensor Problem

Sensor being detected open or shorted or out of temperature range. Demand defrost

control will not perform demand or time/temperature defrost operation. (System will

still heat or cool).

ON ON Fault Demand Defrost Control

Failure

Indicates that demand defrost control has internal component failure. Cycle 24VAC

power to demand defrost control. If code does not clear, replace demand defrost

control.

OFF SLOW

Flash Fault Low Pressure Fault 1Restricted air flow over indoor or

outdoor coil.

2Improper refrigerant charge in

system.

3Improper metering device

installed or incorrect operation

of metering device.

4Incorrect or improper sensor

location or connection to

system.

1Remove any blockages or restrictions from

coils and/or fans. Check indoor and outdoor

fan motor for proper current draws.

2Check system charge using subcooling

method.

3Check system operating pressures and

compare to unit subcooling tables in this

instruction or located on unit access panel.

4Make sure all pressure switches and sensors

have secure connections to system to prevent

refrigerant leaks or errors in pressure and

temperature measurements.

OFF ON Lockout Low Pressure Lockout

SLOW

Flash OFF Fault High Pressure Fault

ON OFF Lockout High Pressure Lockout

SLOW

Flash ON Fault Discharge Line Temperature

Fault This code detects shorted sensor or high discharge temperatures. If the discharge

line temperature exceeds a temperature of 285ºF (140ºC) during compressor

operation, the demand defrost control will de−energize the compressor contactor

output (and the defrost output if active). The compressor will remain off until the

discharge temperature has dropped below 225ºF (107ºC).

FAST

Flash ON Lockout Discharge Line Temperature

Lockout

OFF Fast

Flash Fault Discharge Sensor Fault The demand defrost control detects open sensor or out of temperature sensor range.

This fault is detected by allowing the unit to run for 90 seconds before checking

sensor resistance. If the sensor resistance is not within range after 90 seconds, the

demand defrost control will count one fault. After 5 faults, the demand defrost control

will lockout.

Fast

Flash OFF Lockout Discharge Sensor Lockout

(Each fault adds 1 strike to that code’s counter; 5 strikes per code = LOCKOUT)

Page 33

XP16 SERIES

High Pressure Switch (S4)

When the high pressure switch trips, the demand defrost

control will cycle off the compressor, and the strike counter

in the demand defrost control will count one strike. High

Pressure (auto reset) − trip at 590 psig, reset at 418.

Low Pressure Switch (S87)

When the low pressure switch trips, the demand defrost

control will cycle off the compressor, and the strike counter

in the demand defrost control will count one strike. Low

pressure switch (auto reset) − trip at 25 psig, reset at 40

psig.

The low pressure switch is ignored under the following

conditions:

SDuring the defrost cycle and 90 seconds after the

termination of defrost

SWhen the average ambient sensor temperature is

below 15° F (−9°C)

SFor 90 seconds following the start up of the

compressor

SDuring test mode

Ambient Sensor (RT13)

The ambient sensor considers outdoor temperatures

below −35°F (−37°C) or above 120°F (48°C) as a fault. If the

ambient sensor is detected as being open, shorted or out

of the temperature range of the sensor, the demand

defrost control will not perform demand defrost operation.

The demand defrost control will revert to time/temperature

defrost operation and will display the appropriate fault

code. Heating and cooling operation will be allowed in this

fault condition.

Coil Sensor (RT21)

Coil SensorThe coil temperature sensor considers

outdoor temperatures below −35°F (−37°C) or above 120°F

(48°C) as a fault. If the coil temperature sensor is detected

as being open, shorted or out of the temperature range of

the sensor, the demand defrost control will not perform

demand or time/temperature defrost operation and will

display the appropriate fault code. Heating and cooling

operation will be allowed in this fault condition.

High Discharge Temperature Sensor (RT28)

If the discharge line temperature exceeds a temperature of

285°F (140°C) during compressor operation, the demand

defrost control will de−energize the compressor contactor

output (and the defrost output, if active). The compressor

will remain off until the discharge temperature has dropped

below 225°F (107°C) and the 5-minute anti−short cycle

delay has been satisfied. This sensor has two fault and

lockout codes:

1. If the demand defrost control recognizes five high

discharge line temperature faults during a single (Y1)

compressor demand, it reverts to a lockout mode and

displays the appropriate code. This code detects

shorted sensor or high discharge temperatures. Code

on demand defrost control is Discharge Line

Temperature Fault and Lockout.

2. If the demand defrost control recognizes five

temperature sensor range faults during a single (Y1)

compressor demand, it reverts to a lockout mode and

displays the appropriate code. The demand defrost

control detects open sensor or out-of-temperature

sensor range. This fault is detected by allowing the unit

to run for 90 seconds before checking sensor

resistance. If the sensor resistance is not within range

after 90 seconds, the demand defrost control will count

one fault. After five faults, the demand defrost control

will lockout. Code on demand defrost control is

Discharge Sensor Fault and Lockout.

The discharge line sensor, which covers a range of 150°F

(65°C) to 350°F (176°C), is designed to mount on a ½"

refrigerant discharge line.

NOTE − Within a single room thermostat demand, if

5−strikes occur, the demand defrost control will lockout the

unit. demand defrost control 24 volt power R must be

cycled OFF or the TEST pins on demand defrost control

must be shorted between 1 to 2 seconds to reset the

demand defrost control.

Crankcase Heater (HR1) and Crankcase Thermostat

Switch (S40)

The reference models are equipped with a 70 watt, belly

band type crankcase heater. HR1 prevents liquid from

accumulating in the compressor. HR1 is controlled by a

thermostat located on the liquid line. When liquid line

temperature drops below 50° F the thermostat closes

energizing HR1. The thermostat will open, de−energizing

HR1 once liquid line temperature reaches 70° F .

Liquid Line Bi−Flow Filter Drier

The unit is equipped with a large−capacity biflow filter drier

which keeps the system clean and dry. If replacement is

necessary, order another of like design and capacity. The

replacement filter drier must be suitable for use with

HFC−410A refrigerant.

The replacement filter drier must be suitable for use with

HFC−410A refrigerant.

SECOND−STAGE OPERATION

If the demand defrost control (A108) receives a call for

second−stage compressor operation Y2 in heating or

cooling mode and the first-stage compressor output is

active, the second-stage compressor solenoid output will

be energized.

If first-stage compressor output is active in heating mode

and the outdoor ambient temperature is below the selected

compressor lock−in temperature, the second-stage

compressor solenoid output will be energized without the

Y2 input. If the jumper is not connected to one of the

temperature selection pins on P3 (40, 45, 50, 55°F), the

default lock−in temperature of 40°F (4.5°C) will be used.

The demand defrost control de−energizes the

second-stage compressor solenoid output immediately

when the Y2 signal is removed or the outdoor ambient

temperature is 5°F above the selected compressor lock−in

temperature, or the first-stage compressor output is

de−energized for any reason.

Page 34

Defrost System

This section addresses:

SEmergency Heat

SDefrost System Overview

SDefrost Control Connections, Jumper Settings and

Features

SOperational Mode Overview (Calibration, Normal and

Defrost)

SDefrost Cycle Actuation

EMERGENCY HEAT (AMBER LIGHT)

An emergency heat function is designed into some room

thermostats. This feature is applicable when isolation of the

outdoor unit is required, or when auxiliary electric heat is

staged by outdoor thermostats. When the room thermostat is

placed in the emergency heat position, the outdoor unit

control circuit is isolated from power and field-provided relays

bypass the outdoor thermostats. An amber indicating light

simultaneously comes on to remind the homeowner that he

is operating in the emergency heat mode.

Emergency heat is usually used during an outdoor unit

shutdown, but it should also be used following a power

outage if power has been off for over an hour and the

outdoor temperature is below 50°F (10°C). System should

be left in the emergency heat mode at least six hours to

allow the crankcase heater sufficient time to prevent

compressor slugging.

DEFROST SYSTEM OVERVIEW

The control monitors ambient temperature, outdoor coil

temperature, and total run time to determine when a

defrost cycle is required. The coil temperature probe is

designed with a spring clip to allow mounting to the outside

coil tubing. The location of the coil sensor is important for

proper defrost operation.

NOTE − The demand defrost control accurately measures

the performance of the system as frost accumulates on the

outdoor coil. This typically will translate into longer running

time between defrost cycles as more frost accumulates on

the outdoor coil before the demand defrost control initiates

defrost cycles.

DEFROST CONTROL CONNECTIONS, JUMPERS

SETTINGS AND FEATURES

Pressure Switch 5−Strike Lockout

The internal control logic of the demand defrost control

counts the pressure switch trips only while the Y1 (Input)

line is active. If a pressure switch opens and closes four

times during a Y1 (Input), the control logic will reset the

pressure switch trip counter to zero at the end of the Y1

(Input). If the pressure switch opens for a fifth time during

the current Y1 (Input), the control will enter a lockout

condition.

The 5−strike pressure switch lockout condition can be reset

by cycling OFF the 24−volt power to the demand defrost

control or by shorting the TEST pins between 1 to 2

seconds. All timer functions (run times) will also be reset.

If a pressure switch opens while the Y1 Out line is

engaged, a 5−minute short cycle will occur after the switch

closes.

Demand Defrost Control Pressure Switch

Connections

The unit’s automatic reset pressure switches (LO PS − S87

and HI PS − S4) are factory−wired into the demand defrost

control on the LO−PS and HI−PS terminals, respectively.

Demand Defrost Control Sensors

Sensors connect to the demand defrost control through a

field-replaceable harness assembly that plugs into the

demand defrost control as illustrated in figure 1. Through

the sensors, the demand defrost control detects outdoor

ambient, coil, and discharge temperature fault conditions.

As the detected temperature changes, the resistance

across the sensor changes.

Testing Demand Defrost Control Sensors

Sensor resistance values can be checked by ohming

across pins shown in table 11.

Table 11. Sensor Temperature /Resistance Range

Sensor

Temperature

Range °F (°C)

Resistance values

range (ohms)

Pins/W

ire

Color

Outdoor −35 (−37) to 120 (48) 280,000 to 3750 3 & 4

(Black)

Coil −35 (−37) to 120 (48) 280,000 to 3750 5 & 6

(Brown)

Discharge (if

applicable)

24 (−4) to 350 (176) 41,000 to 103 1 & 2

(Yellow)

Note: Sensor resistance increases as sensed temperature decreases.

Tables 12 and 13 shows how the resistance varies as the

temperature changes for various types of sensors.

NOTE − When checking the ohms across a sensor, be

aware that a sensor showing a resistance value that is not

within the range shown in table 11, may be performing as

designed. However, if a shorted or open circuit is detected,

then the sensor may be faulty and the sensor harness will

need to be replaced.

Defrost Temperature Termination Jumper

Settings (P1)

The demand defrost control selections are: 50, 70, 90, and

100°F (10, 21, 32 and 38°C). The shunt termination pin is

factory set at 50°F (10°C). If temperature shunt is not

installed, default termination temperature is 90°F (32°C).

Test Pins (P1) Function

Placing the jumper on the field test pins (P1) allows the

technician to:

SClear short cycle lockout

SClear five−strike fault lockout

SCycle the unit in and out of defrost mode

SPlace the unit in defrost mode to clear the coil

See figure 27 for flowchart of test pin (P1) operations.

Page 35

XP16 SERIES

Compressor Delay Mode (P5)

The demand defrost control has a field−selectable function

to reduce occasional sounds that may occur while the unit

is cycling in and out of the defrost mode. When a jumper is

installed on the DELAY pins, the compressor will be cycled

off for 30 seconds going in and out of the defrost mode.

Units are shipped with jumper installed on DELAY pins.

NOTE − The 30 second off cycle is NOT functional when

jumpering the TEST pins.

OPERATIONAL MODE OVERVIEW

The demand defrost control has three basic operational

modes. Those modes are:

1. Calibration Mode  The demand defrost control is

considered uncalibrated when power is applied to the

demand defrost control, after cool mode operation, or

if the coil temperature exceeds the termination

temperature when it is in heat mode (see figure 26 for

further details).

2. Normal Mode  The demand defrost control

monitors the O line, to determine the system operating

mode (heat/cool), outdoor ambient temperature, coil

temperature (outdoor coil) and compressor run time to

determine when a defrost cycle is required.

Calibration of the demand defrost control occurs after

a defrost cycle to ensure that there is no ice on the coil.

During calibration, the temperature of both the coil and

the ambient sensor are measured to establish the

temperature differential which is required to allow a

defrost cycle.

3. Defrost Mode  The following paragraphs provide a

detailed description of the defrost system operation.

DEFROST CYCLE ACTUATION

The demand defrost control initiates a defrost cycle based

on either frost detection or time.

1. Frost Detection  If the compressor runs longer than

30 minutes and the actual difference between the clear

coil and frosted coil temperatures exceeds the

maximum difference allowed by the demand defrost

control, a defrost cycle will be initiated.

2. Time  If six hours of heating mode compressor run

time has elapsed since the last defrost cycle while the

coil temperature remains below 35°F (2°C), the

demand defrost control will initiate a defrost cycle.

Actuation

When the reversing valve is de−energized, the Y1 circuit is

energized, and the coil temperature is below 35°F (2°C),

the demand defrost control logs the compressor run time.

If the demand defrost control is not calibrated, a defrost

cycle will be initiated after 30 minutes of heating mode

compressor run time. The control will attempt to

self−calibrate after this (and all other) defrost cycle(s).

Calibration success depends on stable system

temperatures during the 20−minute calibration period. If

the demand defrost control fails to calibrate, another

defrost cycle will be initiated after 45 minutes of heating

mode compressor run time. Once the demand defrost

control is calibrated, it initiates a demand defrost cycle

when the difference between the clear coil and frosted coil

temperatures exceeds the maximum difference allowed

by the control or after six hours of heating mode

compressor run time has been logged since the last

defrost cycle.

Termination

The defrost cycle ends when the coil temperature exceeds

the termination temperature or after 14 minutes of defrost

operation. If the defrost is terminated by the 14−minute

timer, another defrost cycle will be initiated after 30

minutes of run time.

Page 36

DEFROST CONTROL (A108) CALIBRATION MODE SEQUENCE

Occurs after power up and cooling operation, or if the coil temperature exceeds

the termination temperature while in Heat Mode.

Demand defrost control defaults to 30 minute  Time / Temperature Mode

Reset Compressor Runtime / Reset Three / Five Strike Counter

DEMAND MODE

Accumulate compressor runtime of

more than 30 minutes while coil

temperature is below 35° F (2°C).

When the accumulated compressor

time exceeds six (6) hours or if the

coil sensor indicates frost is present

on coil, go to Defrost.

THIRTY (30) MINUTE TIME /

TEMPERATURE MODE

Accumulate compressor runtime

while coil temperature is below 35° F

(2°C). When the accumulated

compressor time exceeds 30 minutes

go to Defrost.

45 MINUTE

TIME/TEMPERATURE MODE

Accumulate compressor runtime

while coil temperature is below 35°

F (2°C). When the accumulated

compressor time exceeds 45

minutes go to Defrost.

DEFROST

SOutdoor Fan OFF

SReversing Valve ON

SW1 line ON

Monitor coil temperature and

time in defrost mode.

HOW DID DEFROST TERMINATE?

Coil temperature was above 35°F (2°C) for four (4)

minutes. of the 14−minute defrost OR reached

defrost termination temperature.

Defrosted for 14−minute without the coil temperature

going above 35°F (2°C) for four (4) minutes and coil

did not reach termination temperature.

Attempt to Calibration  Temperature measurements are not taken for the first few minutes of each heat demand. This is

to allow coil temperatures to stabilize. demand defrost control has a maximum of 20 minutes of accumulated compressor

runtime in heat mode to calibrate demand defrost control This may involve more than one heating demand.

Was stable coil temperature attained

within 20 minutes?

NO  Demand defrost control

reverts to 45 minute time /

temperature.

DEFROST TERMINATION

SCompressor runtime counter RESET

SOutdoor Fan ON

SReversing Valve OFF

SW1 line OFF

DEFROST TERMINATION

SCompressor runtime counter RESET

SOutdoor Fan ON

SReversing Valve OFF

SW1 line OFF

YES  Calibration occurred

Figure 26. Defrost Calibration

Page 37

XP16 SERIES

Table 12. Ambient (RT13) and Coil (RT21) Sensors Temperature / Resistance Range

Degrees

Fahrenheit Resistance Degrees

Fahrenheit Resistance

136.3 2680 56.8 16657 21.6 44154 −11.3 123152

133.1 2859 56.0 16973 21.0 44851 −11.9 125787

130.1 3040 55.3 17293 20.5 45560 −12.6 128508

127.3 3223 54.6 17616 20.0 46281 −13.2 131320

124.7 3407 53.9 17942 19.4 47014 −13.9 134227

122.1 3592 53.2 18273 18.9 47759 −14.5 137234

119.7 3779 52.5 18607 18.4 48517 −15.2 140347

117.5 3968 51.9 18945 17.8 49289 −15.9 143571

115.3 4159 51.2 19287 17.3 50074 −16.5 146913

113.2 4351 50.5 19633 16.8 50873 −17.2 150378

111.2 4544 49.9 19982 16.3 51686 −17.9 153974

109.3 4740 49.2 20336 15.7 52514 −18.6 157708

107.4 4937 48.5 20695 15.2 53356 −19.3 161588

105.6 5136 47.9 21057 14.7 54215 −20.1 165624

103.9 5336 47.3 21424 14.1 55089 −20.8 169824

102.3 5539 46.6 21795 13.6 55979 −21.5 174200

100.6 5743 46.0 22171 13.1 56887 −22.3 178762

99.1 5949 45.4 22551 12.5 57811 −23.0 183522

97.6 6157 44.7 22936 12.0 58754 −23.8 188493

96.1 6367 44.1 23326 11.5 59715 −24.6 193691

94.7 6578 43.5 23720 11.0 60694 −25.4 199130

93.3 6792 42.9 24120 10.4 61693 −26.2 204829

92.0 7007 42.3 24525 9.9 62712 −27.0 210805

90.6 7225 41.7 24934 9.3 63752 −27.8 217080

89.4 7444 41.1 25349 8.8 64812 −28.7 223677

88.1 7666 40.5 25769 8.3 65895 −29.5 230621

86.9 7890 39.9 26195 7.7 67000 −30.4 237941

85.7 8115 39.3 26626 7.2 68128 −31.3 245667

84.5 8343 38.7 27063 6.7 69281 −32.2 253834

83.4 8573 38.1 27505 6.1 70458 −33.2 262482

82.3 8806 37.5 27954 5.6 71661 −34.1 271655

81.2 9040 37.0 28408 5.0 72890 −35.1 281400

80.1 9277 36.4 28868 4.5 74147 −36.1 291774

79.0 9516 35.8 29335 3.9 75431 −37.1 302840

78.0 9757 35.2 29808 3.4 76745 −38.2 314669

77.0 10001 34.7 30288 2.8 78090 −39.2 327343

76.0 10247 34.1 30774 2.3 79465

75.0 10496 33.5 31267 1.7 80873

74.1 10747 33.0 31766 1.2 82314

73.1 11000 32.4 32273 0.6 83790

72.2 11256 31.9 32787 0.0 85302

71.3 11515 31.3 33309 −0.5 86852

70.4 11776 30.7 33837 −1.1 88440

69.5 12040 30.2 34374 −1.7 90068

68.6 12306 29.6 34918 −2.2 91738

67.7 12575 29.1 35471 −2.8 93452

66.9 12847 28.6 36031 −3.4 95211

66.0 13122 28.0 36600 −4.0 97016

65.2 13400 27.5 37177 −4.6 98870

64.4 13681 26.9 37764 −5.2 100775

63.6 13964 26.4 38359 −5.7 102733

62.8 14251 25.8 38963 −6.3 104746

62.0 14540 25.3 39577 −6.9 106817

61.2 14833 24.8 40200 −7.5 108948

60.5 15129 24.2 40833 −8.2 111141

59.7 15428 23.7 41476 −8.8 113400

59.0 15730 23.2 42130 −9.4 115727

58.2 16036 22.6 42794 −10.0 118126

57.5 16345 22.1 43468 −10.6 120600

Page 38

Table 13. High Discharge Sensor (RT28) Temperature / Resistance Range

Degrees

Fahrenheit Resistance Degrees

Fahrenheit Resistance

303.1 183 186.1 1052 136.8 2656 94.5 6613

298.1 195 185.0 1072 136.0 2698 93.6 6739

293.4 207 183.9 1093 135.2 2740 92.8 6869

289.0 220 182.8 1114 134.5 2783 92.0 7002

284.8 232 181.8 1135 133.7 2827 91.2 7139

280.9 245 180.7 1157 132.9 2872 90.3 7281

277.1 258 179.6 1179 132.2 2917 89.5 7426

273.6 270 178.6 1201 131.4 2963 88.6 7575

270.2 283 177.6 1223 130.6 3010 87.8 7729

267.0 297 176.6 1245 129.9 3057 86.9 7888

263.9 310 175.5 1268 129.1 3105 86.0 8051

260.9 323 174.6 1291 128.4 3154 85.2 8220

258.1 336 173.6 1315 127.6 3204 84.3 8394

255.3 350 172.6 1338 126.8 3255 83.4 8574

252.7 364 171.6 1362 126.1 3307 82.5 8759

250.1 378 170.6 1386 125.3 3359 81.6 8951

247.7 391 169.7 1411 124.6 3413 80.7 9149

245.3 405 168.7 1435 123.8 3467 79.8 9354

243.0 420 167.8 1460 123.1 3523 78.8 9566

240.8 434 166.9 1486 122.3 3579 77.9 9786

238.6 448 165.9 1511 121.6 3637 76.9 10013

236.5 463 165.0 1537 120.8 3695 76.0 10250

234.4 478 164.1 1563 120.1 3755 75.0 10495

232.4 492 163.2 1590 119.3 3816 74.1 10749

230.5 507 162.3 1617 118.5 3877 73.1 11014

228.6 523 161.4 1644 117.8 3940 72.1 11289

226.7 538 160.5 1672 117.0 4005 71.1 11575

224.9 553 159.7 1699 116.3 4070 70.0 11873

223.2 569 158.8 1728 115.5 4137 69.0 12184

221.5 584 157.9 1756 114.8 4205 68.0 12509

219.8 600 157.1 1785 114.0 4274 66.9 12848

218.1 616 156.2 1815 113.2 4345 65.8 13202

216.5 632 155.3 1845 112.5 4418 64.7 13573

214.9 649 154.5 1875 111.7 4491 63.6 13961

213.4 665 153.6 1905 111.0 4567 62.5 14368

211.9 682 152.8 1936 110.2 4644 61.3 14796

210.4 698 152.0 1968 109.4 4722 60.2 15246

208.9 715 151.1 1999 108.7 4802 59.0 15719

207.5 732 150.3 2032 107.9 4884 57.8 16218

206.0 750 149.5 2064 107.1 4968 56.6 16744

204.6 767 148.7 2098 106.4 5054 55.3 17301

203.3 785 147.9 2131 105.6 5141 54.0 17891

201.9 803 147.1 2165 104.8 5231 52.7 18516

200.6 821 146.2 2200 104.0 5323 51.4 19180

199.3 839 145.4 2235 103.3 5416 50.0 19887

198.0 857 144.6 2270 102.5 5512 48.6 20641

196.8 876 143.8 2306 101.7 5610 47.2 21448

195.5 894 143.0 2343 100.9 5711 45.7 22311

194.3 913 142.3 2380 100.1 5814

193.1 932 141.5 2418 99.3 5920

191.9 952 140.7 2456 98.5 6028

190.7 971 139.9 2495 97.7 6139

189.5 991 139.1 2534 96.9 6253

188.4 1011 138.3 2574 96.1 6370

187.2 1031 137.6 2615 95.3 6489

Page 39

XP16 SERIES

TEST

Placing the jumper on the field test pins (P1) allows the technician to:

SClear short cycle lockout

SClear five−strike fault lockout

SCycle the unit in and out of defrost mode

SPlace the unit in defrost mode to clear the coil

When Y1 is energized and 24V power is being applied to the Control, a test cycle can be initiated by placing a jumper on the Control’s TEST pins for 2 to

5 seconds. If the jumper remains on the TEST pins for longer than five seconds, the Control will ignore the jumpered TEST pins and revert to normal

operation.

The Control will initiate one test event each time a jumper is placed on the TEST pins. For each TEST the jumper must be removed for at least one

second and then reapplied.

NOTE  Placing a jumper on the TEST pins will not bring the unit

out of inactive mode. The only way manually activate the heat

pump from an inactive mode is to cycle the 24VAC power to the

Control.

Y1 Active

Place a jumper on TEST pins for

longer than one second but less

than two seconds.

Clears any short cycle lockout and

five strike fault lockout function, if

applicable. No other functions will be

executed and unit will continue in the

mode it was operating.

Place a jumper on TEST pins for

more than two seconds.

Clears any short cycle lockout and

five strike fault lockout function, if

applicable.

If in HEATING Mode

If in DEFROST Mode

No further test mode operation will be

executed until the jumper is removed

from the TEST pins and reapplied.

If no ambient or coil sensor fault

exist, unit will go into DEFROST

MODE.

If ambient or coil faults exist (open or

shorted), unit will remain in HEAT

MODE.

The unit will terminate defrost and

enter HEAT MODE uncalibrated

with defrost timer set for 45 minute

test.

If jumper on TEST pins remains in

place for more than five seconds.

The unit will return to HEAT MODE

un−calibrated with defrost timer set

for 34 minutes.

If jumper on TEST pins is removed

before a maximum of five seconds.

The unit will remain in DEFROST

MODE until termination on time or

temperature.

O Line Status INACTIVE

ACTIVE

If in COOLING Mode

Figure 27. Test Pin (P1) Functions

Page 40

Two−Stage Modulation Compressors

Checks

Use this checklist on page 42 to verify part-load and

full-load capacity operation of two-stage modulation

compressors.

TOOLS REQUIRED

SRefrigeration gauge set

SDigital volt/amp meter

SElectronic temperature thermometer

SOn-off toggle switch

IMPORTANT

This performance check is ONLY valid on systems that

have clean indoor and outdoor coils, proper airflow over

coils, and correct system refrigerant charge. All

components in the system must be functioning proper to

correctly perform compressor modulation operational

check. (Accurate measurements are critical to this test

as indoor system loading and outdoor ambient can affect

variations between low and high capacity readings).

PROCEDURE

NOTE − Block outdoor coil to maintain a minimum of 375

psig during testing).

1. Turn main power OFF to outdoor unit.

2. Adjust room thermostat set point 5ºF above the room

temperature.

3. Remove control access panel. Install refrigeration

gauges on unit. Attach the amp meter to the common

(black wire) wire of the compressor harness. Attach

thermometer to discharge line as close as possible to

the compressor.

4. Turn toggle switch OFF and install switch in series with

Y2 wire from room thermostat.

5. Cycle main power ON.

6. Allow pressures and temperatures to stabilize before

taking measurements (may take up to 10 minutes).

7. Record all of the readings for the Y1 demand.

8. Close switch to energize Y2 demand. Verify power is

going to compressor solenoid.

9. Allow pressures and temperatures to stabilize before

taking measurements (may take up to 10 minutes).

10. Record all of the readings with the Y1 and Y2 demand.

11. If temperatures and pressures change in the direction

noted in Two−Stage Modulation Compressor Field

Operational Checklist on page 42, the compressor is

properly modulating from low to high capacity. (If no

amperage, pressures or temperature readings

change when this test is performed, the compressor

is not modulating between low and high capacity and

replacement is necessary).

12. After testing is complete, return unit to original set up.

Maintenance

DEALER

Maintenance and service must be performed by a qualified

installer or service agency. At the beginning of each

cooling season, the system should be checked as follows:

Outdoor Unit

1. Clean and inspect outdoor coil (may be flushed with a

water hose). Ensure power is off before cleaning.

2. Outdoor unit fan motor is pre−lubricated and sealed.

No further lubrication is needed.

3. Visually inspect all connecting lines, joints and coils for

evidence of oil leaks.

4. Check all wiring for loose connections.

5. Check for correct voltage at unit (unit operating).

6. Check amp draw on outdoor fan motor.

Motor Nameplate:_________ Actual:__________.

7. Inspect drain holes in coil compartment base and

clean if necessary.

NOTE - If insufficient heating or cooling occurs, the unit

should be gauged and refrigerant charge should be

checked.

Outdoor Coil

It may be necessary to flush the outdoor coil more

frequently if it is exposed to substances which are

corrosive or which block airflow across the coil (e.g., pet

urine, cottonwood seeds, fertilizers, fluids that may contain

high levels of corrosive chemicals such as salts)

SOutdoor Coil  The outdoor coil may be flushed with

a water hose.

SOutdoor Coil (Sea Coast)  Moist air in ocean

locations can carry salt, which is corrosive to most

metal. Units that are located near the ocean require

frequent inspections and maintenance. These

inspections will determine the necessary need to wash

the unit including the outdoor coil. Consult your

installing contractor for proper intervals/procedures

for your geographic area or service contract.

Indoor Unit

1. Clean or change filters.

2. Lennox blower motors are prelubricated and

permanently sealed. No more lubrication is needed.

3. Adjust blower speed for cooling. Measure the pressure

drop over the coil to determine the correct blower CFM.

Refer to the unit information service manual for pressure

drop tables and procedure.

4. Belt Drive Blowers − Check belt for wear and proper

tension.

5. Check all wiring for loose connections.

6. Check for correct voltage at unit. (blower operating)

7. Check amp draw on blower motor.

Motor Nameplate:_________ Actual:__________.

Page 41

XP16 SERIES

Indoor Coil

1. Clean coil if necessary.

2. Check connecting lines, joints and coil for evidence of

oil leaks.

3. Check condensate line and clean if necessary.

HOMEOWNER

Cleaning of the outdoor unit’s coil should be performed by

a trained service technician. Contact your dealer and set

up a schedule (preferably twice a year, but at least once a

year) to inspect and service your outdoor unit. The

following maintenance may be performed by the

homeowner.

IMPORTANT

Sprinklers and soaker hoses should not be installed

where they could cause prolonged exposure to the

outdoor unit by treated water. Prolonged exposure of the

unit to treated water (i.e., sprinkler systems, soakers,

waste water, etc.) will corrode the surface of steel and

aluminum parts and diminish performance and longevity

of the unit.

Outdoor Coil

The outdoor unit must be properly maintained to ensure its

proper operation.

SPlease contact your dealer to schedule proper

inspection and maintenance for your equipment.

SMake sure no obstructions restrict airflow to the

outdoor unit.

SGrass clippings, leaves, or shrubs crowding the unit

can cause the unit to work harder and use more

energy.

SKeep shrubbery trimmed away from the unit and

periodically check for debris which collects around the

unit.

Cleaning of the outdoor unit’s coil should be performed by

a trained service technician. Contact your dealer and set

up a schedule (preferably twice a year, but at least once a

year) to inspect and service your outdoor unit.

Routine Maintenance

In order to ensure peak performance, your system must be

properly maintained. Clogged filters and blocked airflow

prevent your unit from operating at its most efficient level.

1. Air Filter  Ask your Lennox dealer to show you

where your indoor unit’s filter is located. It will be either

at the indoor unit (installed internal or external to the

cabinet) or behind a return air grille in the wall or

ceiling. Check the filter monthly and clean or replace

it as needed.

2. Disposable Filter  Disposable filters should be

replaced with a filter of the same type and size.

NOTE  If you are unsure about the filter required for your

system, call your Lennox dealer for assistance.

3. Reusable Filter  Many indoor units are equipped

with reusable foam filters. Clean foam filters with a

mild soap and water solution; rinse thoroughly; allow

filter to dry completely before returning it to the unit or

grille.

NOTE  The filter and all access panels must be in place

any time the unit is in operation.

4. Indoor Unit  The indoor unit’s evaporator coil is

equipped with a drain pan to collect condensate

formed as your system removes humidity from the

inside air. Have your dealer show you the location of

the drain line and how to check for obstructions. (This

would also apply to an auxiliary drain, if installed.)

Thermostat Operation

See the thermostat homeowner manual for instructions on

how to operate your thermostat.

Heat Pump Operation

Your new Lennox heat pump has several characteristics

that you should be aware of:

SHeat pumps satisfy heating demand by delivering

large amounts of warm air into the living space. This

is quite different from gas- or oil-fired furnaces or an

electric furnace which deliver lower volumes of

considerably hotter air to heat the space.

SDo not be alarmed if you notice frost on the outdoor coil

in the winter months. Frost develops on the outdoor

coil during the heating cycle when temperatures are

below 45F (7C). An electronic control activates a

defrost cycle lasting 5 to 15 minutes at preset intervals

to clear the outdoor coil of the frost.

SDuring the defrost cycle, you may notice steam rising

from the outdoor unit. This is a normal occurrence. The

thermostat may engage auxiliary heat during the

defrost cycle to satisfy a heating demand; however,

the unit will return to normal operation at the

conclusion of the defrost cycle.

Extended Power Outage

The heat pump is equipped with a compressor crankcase

heater which protects the compressor from refrigerant

slugging during cold weather operation.

If power to your unit has been interrupted for several hours

or more, set the room thermostat selector to the

EMERGENCY HEAT setting to obtain temporary heat

without the risk of serious damage to the heat pump.

In EMERGENCY HEAT mode, all heating demand is

satisfied by auxiliary heat; heat pump operation is locked

out. After a six-hour compressor crankcase warm-up

period, the thermostat can be switched to the HEAT setting

and normal heat pump operation may resume.

Preservice Check

If your system fails to operate, check the following before

calling for service:

SVerify room thermostat settings are correct.

SVerify that all electrical disconnect switches are ON.

SCheck for any blown fuses or tripped circuit breakers.

SVerify unit access panels are in place.

SVerify air filter is clean.

SIf service is needed, locate and write down the unit

model number and have it handy before calling.

Page 42

Accessories

For update−to−date information, see any of the following

publications:

SLennox XP16 Engineering Handbook

SLennox Product Catalog

SLennox Price Book

Checklists

Two−Stage Modulation Compressors Field Operational Checklist

Unit Readings Y1 − First-Stage

Expected results during Y2 demand

(Toggle switch On) Y2 − Second-Stage

COMPRESSOR

Voltage Same

Amperage Higher

OUTDOOR UNIT FAN MOTOR

Amperage Same or Higher

TEMPERATURE

Ambient Same

Outdoor Coil Discharge Air Higher

Compressor Discharge Line Higher

Indoor Return Air Same

Indoor Coil Discharge Air Lower

PRESSURES

Suction (Vapor) Lower

Liquid Higher

Page 43

XP16 SERIES

XP16 Start−Up and Performance

Customer Address

Indoor Unit Model Serial

Outdoor Unit Model Serial

Notes:

START UP CHECKS

Refrigerant Type:

1st Stage: Rated Load Amps Actual Amps Rated Volts Actual Volts

2nd Stage: Rated Load Amps Actual Amps Rated Volts Actual Volts

Outdoor Unit Fan Full Load Amps Actual Amps: 1st Stage 2nd Stage

COOLING MODE

Suction Pressure: 1st Stage: 2nd Stage:

Liquid Pressure: 1st Stage: 2nd Stage:

Supply Air Temperature: 1st Stage: 2nd Stage:

Temperature: Ambient: Return Air:

System Refrigerant Charge (Refer to manufacturer’s information on unit or installation instructions for required subcooling and approach tempera-

tures.)

Subcooling: A



SUBCOOLING

Saturated Condensing Temperature (A) minus Liquid

Line Temperature (B)

Approach: A



APPROACH

Liquid Line Temperature (A) minus Outdoor Air

Temperature (B)

Indoor Coil Temperature Drop (18 to 22°F) A



COIL TEMP DROP

Return Air Temperature (A) minus Supply Air

Temperature (B)

Lenox Air Conditioner Elite Series Xp16 Units Heat Pumps Users Manual 506640a

Lenox Air Conditioner Elite Series XP16 Units Heat Pumps Lennox_XP16_IOM

Elite Series XP16 Units Heat Pumps to the manual 4a0ca56a-af7f-4082-a8f4-4c8427d7732c

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