CARRIER Package Units(both Units Combined) Manual L1001389

User Manual: CARRIER CARRIER Package Units(both units combined) Manual CARRIER Package Units(both units combined) Owner's Manual, CARRIER Package Units(both units combined) installation guides

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Installation

Instructions

NOTE:
Read the entire instruction manual before starting the
installation.
NOTE:
Installer: Make sure the Owner's Manual and Service
Instructions are left with the unit after installation,

TABLE

OF CONTENTS

SAFETY CONSIDERATIONS
.........................
INTRODUCTION
...................................
RECEIVING AND INSTALLATION .................
Check Equipment ..................................
Identify Unit ....................................
Inspect Shipment .................................
Provide Unit Support ...............................
Roof Curb ......................................
Slab Mount .....................................
Field Fabricate Ductwork ............................
Provide Clearances .................................
Rig and Place Unit .................................
Connect Condensate Drain ...........................
Install Flue Hood ...................................
Install Gas Piping ..................................
Install Duct Connections .............................

PAGE
1
2
2-14
2
2
2
2
2
2
2
3
7
8
8
8
9

Configuring Units for Downflow (Vertical)
Discharge ......................................
9
Install Electrical Connections ........................
13
High-Voltage Connections ........................
13
Special Procedures for 208-V Operation ..............
13
Control Voltage Connections .......................
13
Balance Point Setting Thermidistat or Hybrid Heat
Thermostat ....................................
14
Transformer Protection ...........................
14
PRE-START-UP
...................................
14
START-UP .....................................
15-19
Check for Refrigerant Leaks .........................
15
Unit Sequence of Operation .........................
15
Start-Up Heating and Make Adjustments ...............
15
Checking Heating Control .........................
16
Check Gas Input ................................
16
Adjust Gas Input ................................
16
Check Burner Flame .............................
17
Start-Up Cooling and Make Adjustments ...............
18
Checking Cooling Control Operation ................
18
Checking and Adjusting Refrigerant .................
18
Indoor Airflow and Airflow Adjustments .............
18
Continuous Fan Operation ........................
19
MAINTENANCE ................................
29-35
Air Filter ........................................
29
Indoor Blower and Motor ...........................
29
Flue Gas Passageways ..............................
30
Limit Switch .....................................
30
Burner Ignition ...................................
30
Main Burners ....................................
30
Outdoor Coil, Indoor Coil, & Condensate Drain Pan ......
30

A0g033

Fig. 1 - Unit 48VT-A
Outdoor Fan .....................................
Electrical Controls and Wiring .......................
Refrigerant Circuit .................................
Gas Input ........................................
Indoor Airflow ...................................
Check Defrost Thermostat ...........................
Puron® Items ....................................
TROUBLESHOOTING
..............................
START-UP CHECKLIST ............................

SAFETY
Improper

installation,

31
31
31
32
32
32
32
35
35

CONSIDERATIONS
adjustment,

alteration,

service

maintenance,

or use can cause explosion,
fire, electrical
shock,
or other
conditions
which may cause death, personal injury, or property
damage.
Consult a qualified
installer,
service agency,
distributor
or branch for information
or assistance. The

or your
qualified

installer or agency must use factory-authorized
kits or accessories
when modifying
this product. Refer to the individual
instructions
packaged with the kits or accessories when installing.
Follow all safety codes.
and work gloves. Have
instructions
thoroughly
included
in literature
building
(NFGC)
(NEC)

codes,
NFPA

Wear safety glasses, protective
clothing,
a fire extinguisher
available. Read these
and follow
and attached

all warnings
to the unit.

the current editions of the National
54/ANSI Z223.1, and the National

or cautions
consult
local
Fuel Gas Code
Electrical Code

NFPA 70.

In Canada
Canada

refer to the current
CAN/CSA-BI49.1

editions
and

Installation

codes,

and Canadian

Recognize

safety

information.

of the National

.2 Natural

Electrical

Gas

Standards
and

Propane

Code CSA C22A

This is the safety-alert

symbol

/_.

When you see this symbol on the unit and in instructions
or manuals, be alert to the potential for personal injury. Understand
these

signalwords:DANGER,
WARNING,
andCAUTION.
These
words
areused
withthesafety-alert
symbol.
DANGER
identifies
themost
serious
hazards
whichwill result in severe personal iniury

INSPECT

or death. WARNING
signifies hazards which could result in personal injury or death. CAUTION
is used to identify unsafe practices which may result in minor personal injury or product and prop-

have it examined
by transportation
Forward
claim
papers
directly

erty damage. NOTE is used
result in enhanced installation,

ELECTRICALSHOCK
Failure to follow
iniury or death.

to highlight
suggestions
reliability, or operation.

which

will

Inspect for shipping damage before removing packaging materials.
If unit appears to be damaged or is torn loose from its anchorage,
inspectors
before removal.
transportation
company.

Manufacturer
is not responsible
for any damage incurred in transit.
Check all items against shipping
list. Immediately
notify the
nearest equipment
distribution
prevent loss or damage, leave
installation.

office if any item
all parts in original

is missing. To
packages until

If the unit is to be mounted on a curb in a downflow
application,
review Step 9 to determine which method is to be used to remove

HAZARD
this warning

SHIPMENT

could

result

in personal

Before installing or servicing system, always turn off main
power to system.
There may be more than one disconnect
switch.
Turn
off accessory
heater
power
switch
if
applicable. TAG THE DISCONNECT
SWITCH
WITH A
SUITABLE WARNING
LABEL.

the downflow
panel removal

panels
process

Step 2 -For

before rigging and lifting into place. The
may require the unit to be on the ground.

Provide

hurricane

Unit Support

tie downs,

(Professional

contact

Engineering)

ROOF

CURB

Install

accessory

distributor

Certificate

for details

roof curb in accordance

with instructions

with curb (See Fig. 4). Install insulation,
cant strips,
flashing. Ductwork must be attached to curb.
IMPORTANT:
FIRE,
EXPLOSION,
CARBON
MONOXIDE

ELECTRICAL
POISONING

SHOCK
HAZARD

AND

critical

The

for a water

gasketing

tight

of the

seal.

Install

with the roof curb. Improperly

and PE

if required.

unit

and

to the roof

curb

material

supplied

gasketing

applied

shipped

roofing,

gasketing

also can result in

air leaks and poor unit performance.
Failure to follow this
iniury, death or property

warning
damage.

could

result

in personal

A
qualified
installer
or
agency
must
use
factory-authorized
kits or accessories
when modifying
product.

only
this

Curb should be level to within 1/4 in. (6 mm). This is necessary for
unit drain to function
properly.
Refer to accessory
roof curb
installation

instructions

Installation

on older

for additional
"G"

series

information

as required.

roof curbs.

Two accessory kits are available to aid in installing
series unit on an old "G" roof curb.

a new

"G"

1. Accessory
kit number CPADCURB001A00,
(small chassis)
and accessory
kit number
CPADCURB002A00,
(large
CUT

HAZARD

Failure

to follow

this caution

may

result in personal

chassis) includes
roof curb adapter and gaskets for the
perimeter
seal
and
duct
openings.
No
additional
modifications
to the curb are required when using this kit.

iniury.

When removing access panels (see Fig. 19) or performing
maintenance
functions inside your unit, be aware of sharp
sheet metal parts and screws. Although
special care is taken
to reduce sharp edges to a minimum,
be extremely careful
when handling parts or reaching into the unit.

2. An alternative to the adapter curb is to modify the existing
curb by removing
the outer horizontal
flange
and use
accessory

INTRODUCTION
The 48VT-A
unit
combination
Category

(see Fig.
1) is a
I gas heating/electric

installed

either

ground,

a rooftop,

if local codes permit

a cement

slab,

or directly

(See Fig. 4 for roof curb dimensions).

These models meet the California
maximum
oxides of nitrogen
(NOx) emissions
requirements
of 40 nanograms/joule
or less as
shipped from the factory and must be installed in California Air
Management
Districts
or any
where a Low NOx rule exists.

RECEIVING
Step 1 -- Check
IDENTIFY

regions

in North

Equipment

number

plate. Check

this information

are stamped
against

flange.

UNIT/STRUCTURAL
Failure

DAMAGE

to follow this caution

HAZARD

may result in property

damage.

Ensure there is sufficient clearance for saw blade when cutting
the outer horizontal
flange of the roof curb so there is no
damage to the roof or flashing.
SLAB

MOUNT

Place the unit on a solid, level concrete

pad that is a minimum

of 4

in. (102 mm) thick with 2 in. (51 mm) above grade. The slab
should be flush on the compressor
end of the unit (to allow

Step 3 -and serial number

which includes

condensate
drain installation)
and should extend 2 in. (51 mm) on
the three remaining
sides of the unit. Do not secure the unit to the
slab except when required by local codes.

INSTALLATION

UNIT

The unit model
information

AND

other

CPGSKTKIT001A00

on the

Models with an N in the fifth position of the model number are
dedicated
Low NOx units designed
for California
installations.

Quality
America

horizontal

fully
self-contained,
heating and cooling

unit designed
for outdoor installation
(See Fig. 2 and 3 for unit
dimensions).
All unit sizes have return and discharge openings for
both horizontal
and downflow
configurations,
and are factory
shipped with all downflow
duct openings covered. Units may be

kit number

spacer blocks (for easy alignment
to existing
curb) and
gaskets for the perimeter seal and duct openings. This kit is
used when existing curb is modified
by removing
outer

on the unit

shipping

papers.

Field Fabricate

Ductwork

Secure all ducts to roof curb and building
structure
on vertical
discharge units. Do not connect ductwork
to unit. For horizontal
applications,
unit is provided
openings.
All ductwork
should
and weatherproof

all external

with flanges
on the horizontal
be secured to the flanges. Insulate
ductwork,

joints,

and roof openings

withcounter
flashing
andmastic
in accordance
withapplicable
codes.
Ducts
passing
through
anunconditioned
space
must
beinsulated
andcovered
withavapor
barrier.
If aplenum
return
isused
onavertical
unit,thereturn
should
be
ducted
through
theroofdeck
tocomply
withapplicable
firecodes.
Read
unitrating
plate
foranyrequired
clearances
around
ductwork.
Cabinet
return-air
static
shallnotexceed
-.25IN.W.C.
Step 4 -- Provide

Clearances

The required minimum
in Fig. 2 and 3.

operating

IMPORTANT:
at either
detrimental

the

not restrict

outdoor-air

to compressor

inlet
life.

condenser

fan

pulls

air through

the

condenser

coil

and

discharges
it through the top grille. Be sure that the fan discharge
does not recirculate to the condenser coil. Do not locate the unit in
either a corner or under an overhead
obstruction.
The minimum
clearance
overhang)
horizontal
(1219

under a partial overhang
(such as a normal
house
is 48-in. (1219 mm) above the unit top. The maximum
extension of a partial overhang must not exceed 48-in.

mm).

Do not place the unit where water, ice, or snow from an overhang
or roof will damage or flood the unit. Do not install the unit on

and service
outdoor
or

The

the

clearances

airflow.
fan

are shown

An air restriction

discharge

may

carpeting
on wood

or other combustible
materials. The unit may be installed
flooring or on Class A, B, or C roof covering materials.

<\ii

8
o

sl>I_-Jl_-_
_l

i, r

s
is

i• x

o__o_

bi
N...............................................
i .........

_ _

o_
_q

°Ki'

F-

SNo_

A09416

Fig. 2 - 48VT-A24-30

Unit Dimensions

7
_j

_
_,,<,

o_>

-ii _,__
[_J
i_

'ii_

> Q
_o

.....................
,;_;.............................

A09417

Fig. 3 - 48VT-A36-60

[]nit Dimensions

base
rails

Gasket

HVAC
unitI
Anchor

Roofcurb

screw j

Flashing

field

supplied

Wood nailer*
/

Roofcurb*
Insulation

/(field

supplied)

Roofing material
field supplied
Cant strip

SMALL CURB

A09418

A09090

ROOF CURB DETAIL

F A
E

LARGE CURB

A09415

A09419
CATALOG
NUMBER

UNIT SIZE
Small

Large

A
IN. (mm)

CPRFCURB010A00

11 (279)

CPRFCURB011A00

14 (356)

CPRFCURB012A00

11 (279)

CPRFCURB013A00

B
IN. (mm)*

C
IN. (mm)

D
IN. (mm)

16 (406)

47.8
(1214)

10 (254)
14 (356)

14 (356)

E
IN. (mm)

F
IN. (mm)

32.4 (822)

G
IN. (mm)
30.6 (778)

2.7 (69)
43.9
(1116)

H
IN. (mm)

46.1 (1170)
42.2 (1072)

NOTES:
1. Roof

curb

Seal

strip

Roof

Attach

Insulated

curb

must
must

be set up for unit
be applied,

is made

ductwork

IMPORTANT:

of 16-gauge
to curb

panels:

1-in.

not

being

as required,

being

of duct

mm)

install

thick

large

units onto the small base pan (common

rest on curb).
fiberglass

base

1 lb. density.

pan

curb).

HEAT unit could

causing

Before

condition.

unit onto the common

curb, check

installing

the "Y"

HYBRID

HEAT

The center of gravity

on a large base pan HYBRID
an unsafe

installed.

steel.

(flanges
(25.4

installed.
to unit

overhang

the curb

any large base pan

distance

literature dimensional drawing to ensure that "Y" is greater than 14
in. (356 ram). Do not install any large base pan unit onto the
common curb with a "Y" dimension (center of gravity) less than 14
in. (356 mm).

in the product
Fig. 4 - Roof Curb

Dimensions

DUCTS

MINIMUM HEIGHT: 36" (9!4.4 ram)
HAUTEUR MINIMUM

SEAL

UNIT HEIGHT

HAUTEUR
J"

STRIP

MUST

PLACE
BEFORE
UNIT ON ROOF

BANDE

PLACING
CURB

SCELLANT

BOIT

EN PL,_C E AVANT
DE
L=U NITE SUR
LA BASE

ETRE

PLACER
DE TOIT

D'UNITE

DETAIL A
VOIR DIETAIL A
SEE DE,TAIL A
VOIB DETAIL A

50CY502286

2,0
A09051

Unit
Rigging
Weight

Unit

374

170

366

166

Rigging
Weight

203

494

224

514

233

548

249

Step 5 -- Rig and Place Unit

Suggested

Rigging

Inspection
Prior

INJURY

PROPERTY
could

DAMAGE

result

When installing the unit on a rooftop,
support the additional weight.

intervals,

all rigging

shackles,

straps should be visually
inspected
for any
of wear, structural
deformation,
or cracks.
should be paid to excessive
wear at hoist

in personal

be sure the roof will
UNIT

Rigging
and handling
of this equipment
can be hazardous
for
many reasons
due to the installation
location (roofs,
elevated
etc.).

Only trained,
should handle

to initial use, and at monthly

clevis pins,
and
damage,
evidence
Particular
attention

hooking points and load support areas. Materials showing any kind
of wear in these areas must not be used and should be discarded.

Failure to follow
this warning
iniury, death or property damage.

structures,

448

NOTE: See dimensional drawing for corner weight distribution.
Fig. 5 - 48VT-A

PERSONAL
HAZARD

FALLING

HAZARD

Failure to follow
iniury or death.

this warning

Never stand beneath
qualified crane operators
and install this equipment.

and ground

support

rigged

could

result

in personal

units or lift over people.

staff

When working
with this equipment,
observe precautions
in the
literature, on tags, stickers, and labels attached to the equipment,
and any other safety precautions
Training

for operators

not be limited

that might

of the lifting

PROPERTY

apply.

equipment

should

of the lifter to the load,

lifts to adapt to various

and adjustment

in any special

3. Condition

of the load as it relates to operation

kit, such as balance,
all applicable

safety

of the

sizes or kinds of loads.

2. Instruction

gloves.

but

to, the following:

1. Application

include,

operation

temperature,
codes.

Failure
to
iniury/death
When

straps

DAMAGE

HAZARD

follow
this warning
or property damage.
are taut, the clevis

in. (914 mm) above

could

should

result

in personal

be a minimum

of 36

the unit top cover.

or precaution.
of the lifting

Lifting

etc.

Wear

Ri_gin_/Liftin_

safety

shoes

and work

of Unit

holes are provided

(See

Fi_.

in base rails as shown

in Fig. 2 and 3.

1. Leave top shipping skid on the unit for use as a spreader bar
to prevent the rigging straps from damaging the unit. If the
skid is not available, use a spreader
to protect the unit from damage.
2. Attach

shackles,

clevis pins,

the unit. Be sure materials
unit (See Fig. 5).

bar of sufficient

and straps to the base

are rated to hold the weight

length
rails of
of the

3. Attach a clevis

of sufficient

strength

straps. Adjust the clevis location
with the ground.

in the middle

After the unit is placed
the top skid.

on the roof curb or mounting

Step 6 -- Connect

Condensate

NOTE:

When

comply
Model

installing

of the

Install

to ensure unit is lifted level

1. This

pad, remove

Drain

condensate

drain connection

48VT-A

disposes

the outlet
drain-pan
overflowing

connection

water

through

a 3/4 in.

the compressor

access

panel (See

to ensure proper

make sure it slopes

If the installation

requires

drainage.

Make sure that

away from the unit.

draining

the condensate

water

away

a drain tube - using a minimum

horizontal

run. Be sure to check the drain

flue hood

from shipping

location

(inside

the return

over flue panel.

Orient

screw

holes

in flue hood

the top flange

Step 8 -The gas
provided.
(12.7

and the bottom

a single screw on

flange of the hood.

Install Gas Piping

supply pipe enters
The gas connection

mm)

the unit through the access hole
to the unit is made to the l/2-in.

FPT gas inlet on the gas valve.

It is recommended
that a black iron pipe is used. Check the
utility for recommendations
concerning
existing lines. Size
piping

use pipe smaller
unit gas valve.

for 0.5 IN. W.C. maximum
than the l/2-in.

gas applications,

(12.7

pressure

drop. Never

mm) FPT gas inlet on the

the gas pressure

at unit gas connection

must not be less than 4.0 IN. W.C. or greater than 13 IN. W.C.
while the unit is operating.
For propane
applications,
the gas
pressure must not be less than 11.0 IN. W.C. or greater than 13 IN.
W.C. at the unit connection.
A l/8-in. (3.2 mm) NPT plugged tapping, accessible for test gauge
connection,
must be installed immediately
upstream
of the gas
supply connection to the gas valve.

TRAP

When installing the gas supply line, observe local codes pertaining
to gas pipe installations.
Refer to the NFGC
NFPA 54/ANSI

rain.

mm) min.

Z223.1

latest edition

NOTE:

In the state of Massachusetts:

1. Gas supply
plumber
2. When
A09052

Fig. 6 - Condensate

Trap

assembly

is secured

and shipped

duct cover to locate the assembly
Dedicated
low NOx models

California
Air Quality
rule exists.
meet

Management

where

maximum

of 40

air duct.

oxides

nanograms/joule
apply

MUST

B149.1).

be performed

a Low

in
NOx

of nitrogen
or less as

only

natural

gas

by a licensed

or gas fitter.
flexible

connectors

are used,

the maximum

4. The use of copper tubing for gas piping
by the state of Massachusetts.
In the absence of local building
pertinent recommendations:

length

codes,

adhere

shutoff

is NOT

valves

approved

to the following

low spots in long runs of pipe. Grade all pipe 1/4 in.

(6.35 mm) for every 15 ft (4.6 m) of length to prevent traps.
Grade all horizontal
runs downward
to risers. Use risers to
connect

requirements

connections

CAN/CGA

shall not exceed 36 in. (915 mm).

1. Avoid
the California

(NOx) emissions
requirements
shipped from the factory.
NOx

in the return

(See Fig. 8).
MUST be installed

Districts

(in Canada,

3. When lever handle type manual equipment
are used, they shall be T-handle
valves.

Step 7 -- Install Flue Hood

NOTE:
Low
installations.

Refer to Provincial
and
codes and other applicable

3. Secure flue hood to flue panel by inserting

For natural

of 3/4-in. PVC or 3/4-in. copper pipe (all field-supplied)
- at the
outlet end of the 2-in. (51 mm) trap. Do not undersize
the tube.
Pitch the drain tube downward
at a slope of at least 1-in. (25 mm)

models

codes

Install a gas supply line that runs to the heating section. Refer to
Table 2 and the NFGC for gas pipe sizing. Do not use cast-iron

is at least 1 in. (25 mm) lower than the
connection.
This prevents the pan from

Prime the trap with water. Connect

These

latest revision.
or wastewater

assembly

gas supply

Remove
NOTE:

building

local
local

the outlet of the trap
drain-pan
condensate
overflowing.

The flue

local

B149.2)
plumbing
codes.

pipe.
local

l-in. (25 ram)

with

54 /
and

from the unit, install a 2-in. (51 mm) trap at the condensate
connection to ensure proper drainage (See Fig. 6). Make sure that

for every 10 fl (3 m) of
tube for leaks.

conform

with holes in the flue panel.

of the trap is at least 1 in. (25 mm) lower than the
condensate
connection
to prevent
the pan from
(See Fig. 6). Prime the trap with water. When using a

gravel apron,

must

section of the blower compartment-see
Fig. 8). Remove the
return duct cover to locate the flue hood. Place flue hood

Condensate
water can be drained directly onto the roof in rooftop
installations
(where permitted)
or onto a gravel apron in ground
level installations.
Install a field-supplied
condensate trap at end
of condensate

installation

and with the National Fuel Gas Code (NFGC) NFPA
ANSI
Z223A,
(in Canada,
CAN/CGA
BI49A,

2. Remove

of condensate

as follows:

be sure to

with local codes and restrictions.

NPT fitting which exits through
Fig. 2 and 3 for location).

the flue hood

to heating

section

and to meter.

2. Protect all segments of piping system against physical and
thermal damage. Support all piping with appropriate straps,
hangers, etc. Use a minimum of one hanger every 6 ft (1.8
m). For pipe sizes larger than 1/2 in., (12.7 mm)
follow
recommendations
of national codes.

CARBON

MONOXIDE

Failure to follow
iniury or death.

POISONING

this warning

could

HAZARD
result

in personal

The venting system is designed to ensure proper venting.
The flue hood assembly must be installed as indicted in this
section of the unit installation
instructions.

3. Apply joint compound
(pipe dope) sparingly
and only to
male threads of joint when making pipe connections.
Use
only pipe dope that is resistant
to action
of liquefied
petroleum gases as specified by local and/or national codes.
Never use Teflon tape.
4. Install sediment
Fig. 7). This
condensate,

trap in riser leading
drip

leg

functions

to heating
as

a trap

section
for

dirt

(See
and

made specifically
for the detection
of leaks
specified by local codes and/or regulations).

Step 9 --

(or method

Install Duct Connections

The unit has duct flanges on the supplyand return-air
openings
on the side and bottom of the unit. For downshot
applications,
the
ductwork
connection

connects
to the roof
sizes and locations).

Configuring

curb

(See

Fig.

and

for

Units for Downflow (Vertical) Discharge

TEE
ELECTRICALSHOCK

NIPPLE

Failure to follow
or death.

CAP

Before installing or servicing system, always turn off main
power to system. There may be more than one disconnect
switch. Tag the disconnect switch with a suitable warning
label.

C99020

Fig. 7 - Sediment
5. Install

an accessible,

gas supply

Trap

external,

pipe within

manual

main

shutoff

6 fl (1.8 m) of heating

6. Install ground-joint
union
unit manual shutoff and

valve in

section.

dose to heating section
external manual main

between
shut-off

valve.
7. Pressure
national
to unit.
NOTE:
piping

Pressure

disconnected
systems

test the gas supply

unit

from
piping

the gas valve
system

heating
by dosing

slightly

opening

the

is in excess
must

external

the ground-joint

after the gas supply

The supply

during

at pressures

section

system

to the gas valve.

when test pressure

gas supply
The

test all gas piping in accordance
with local and
plumbing
and gas codes before connecting
piping

is connected

piping

the testing

must

of the piping

of 0.5 psig. Pressure

test the

equal to or less than 0.5 psig.

be isolated
main

from

manual

HAZARD

the gas piping

shutoff

valve

and

union.

this warning

could result in personal

iniury

1. Open all electrical disconnects before starting any servace
work.
2. Remove horizontal (metal) duct covers to access vertical
(downflow) discharge duct knockouts in unit basepan. (See
Fig. 8.)
3. Using Fig. 9 as a guide, proceed to cut out the downflow
duct panels.
4. Drill 1/2 in. (13 mm) diameter or larger holes in all four
corners of duct panels.
NOTE:
On large chassis units remove sheet metal shields on
panels by using a crew driver to shear off retainers and discard.
5. On left and side supply duct opening side with keyhole or
single bladed hacksaw cut out panel along "V" groove.
6. On right side, with keyhole or single blade hacksaw, with
teeth facing up and starting from the front and moving to
the rear, cut along "V" groove.
7. Now with three sides cut, flex panel up and down to remove.
8. Replace side access panel and duct cover.

FIRE

OR EXPLOSION

HAZARD

Failure to follow this warning could result in personal iniury,
death and/or property damage.
-Connect gas pipe to unit using a backup wrench to avoid
damaging gas controls.
-Never purge a gas line into a combustion
chamber. Never
test for gas leaks with an open flame. Use a commercially
available soap solution made specifically
for the detection of
leaks to check all connections.
-Use proper
manifold.

length

of pipe

to avoid

stress

gas control

-If a flexible connector is required or allowed by authority
having jurisdiction,
black iron pipe shall be installed
at
furnace gas valve and extend a minimum
of 2 in. (51 mm)
outside furnace casing.
-If codes allow a flexible
connector,
always
use a new
connector,
do not use a connector
which has previously
serviced another gas appliance.

8. Check
for
factory-installed
been completed.

gas
leaks
at
the
field-installed
gas lines after all piping connections
Use a commercially

available

and
have

soap solution

9. After completing unit conversion, perform all safety checks
and power up unit.
Alternate Method
1. Open all electrical disconnects and install lockout tag before
starting any service work.
2. Remove horizontal (metal) ductcovers to access vertical
(downflow) discharge duct knockouts in unit basepan. (See
Fig. 8.)
3. Leave top shipping crate on unit during this method.
4. Tip unit over on the front side (access panels) so the bottom
of the base pan is accessible.
5. Drill two holes diagonally opposed, of suitable size to accommodate jigsaw or reciprocating saw. (See Fig. 9.)
NOTE:
On large chassis units remove sheet metal shields on
panels by using a screw driver to shear off retainers and discard.

[]NIT

COMPONENT

DAMAGE

HAZARD

Failure to follow this caution may result in damage to the
unit being installed.
When cutting duct panels, do not contact or damage any
internal components (heat exchanger, electric heat). Do not
use a saw blade that protrudes more than 1 in. (25 mm) into
unit.

1. Units are shipped
for
removing duct covers).
2. Select
PROPERTY
Failure

DAMAGE

HAZARD

to follow this caution

return-air

may result in property

Collect ALL screws that were removed.
on rooftop

as permanent

6. Using a suitable
panels.

damage

unit conversion,

and remove

perform

duct

ensure weather

air conditioning

all safety checks

and ventilating

NFPA

90B;

Adhere

criteria

when

to the

installing

following

(by

registers,

and

supply-air

to American

Society

Engineers

of Heating,
(ASHRAE)

and/or

systems,
local

selecting,

codes

sizing,

tight and airtight seal.

4. All units must have field-supplied
filters or accessory
rack
installed
in the
return-air
side
of the
Recommended
sizes for filters are shown in Table 1.

filter
unit.

5. Size all ductwork
for maximum
required
airflow (either
heating or cooling)
for unit being installed.
Avoid abrupt
duct size increases or decreases
or performance
may be
affected.

NOTE:
The design and installation
of the duct system must be in
accordance
with the standards
of the NFPA for installation
of
90A or residence-type,
ordinances.

installation

3. Use flexible transition between
rigid ductwork
and unit to
prevent transmission
of vibration.
The transition
may be
screwed or bolted to duct flanges. Use suitable gaskets to

up unit.

nonresidence-type

ductwork,

duct

Do not leave screws

7. Tip unit back onto its base and replace duct covers.
and power

size

grilles according

Refrigeration
and Air Conditioning
recommendations.

damage.

to the roof may occur.

saw cut along "V" groove

8. After completing

and

horizontal

NFPA
and

and

the duct system:

Table
Unit Size
Nominial
Shipping

Capacity
- ton
Weight (Ib)
(kg)
Compressor
Quantity
Type
Refrigerant
Refrigerant
Quantity
(Ib)
Quantity
(kg)
Refrigerant
Metering
Device
Orofice OD (in)
(mm)
Outdoor
Coil
Rows...

1 - Physical

Data

- Unit

48VT-A

24040

24060

30040

30060

36060

36090

2
354
161

2.5
346
157

3
426
193

9.9
4.5

0.038 (2)
0.97 (2)

1
Scroll
R- 41 OA
11.1
5.0

11.1
5.0
Indoor
0.032 (2)
0.81 (2)

0.032 (2)
0.81 (2)

Fins/in,

10.3
4.7
TXV, Outdoor
0.037 (2)
0.94 (2)

10.3
4.7
Dual Accuraters
0.037 (2)
0.94 (2)

2...21

face area (sq. ft.)
Outdoor
Fan

13.6

Nominal
Diameter

2500
24

2700
24

31 O0
26

610
1/10 (810)

610
1/5 (810)

660
1/5 (810)

3...17

3.7

4.7

800
lOx 10
254 x 254

1000
lOx 10
254 x 254

1200
11 x 10
279 x 254

1/2

3/4

2...44

2...38

2...44

2...38

3...38

2...55

2...53

2...55

2...53

3...53

Airflow
(in.)

(cfm)

Diameter
(mm)
Motor hp (rpm)
Indoor Coil
Rows...

Fins/in,

face area (sq. ft.)
Indoor Blower
Nominal Airflow
Size (in.)
Size (mm)

(cfm)

Motor hp
Furnace Section*
Burner Orifice
Natural

Gas Qty...Drill

Size

Propane
Gas Qty...Drill
Size
High Pressure Switch (psig)
Cutout
Reset (Auto)
Loss- of- Charge/Low
Cutout

Pressu re Switch

(in)
(mm)

420 +/-

(psig)
20 +/-

Reset (Auto)
Return Air Filtersl-$
disposable

650 +/-

45 +/20x20x1
508x508x25

5
10

20x24x1
508x610x25

24x30x1
610x762x25

*Based on altitude of 0 to 2000 ft (0-610 m).
1-Required filter sizes shown are based on the larger of the ARI (Air Conditioning and Refrigeration Institute) rated cooling airflow or the heating airflow velocity of
300 ft/minute for high-capacity
type. Air filter pressure drop for non-standard
filters must not exceed 0.08 IN. W.C.
:l: If using accessory filter rack refer to filter rack installation instructions for correct filter size and quantity.

UnitSize
Nominial
Capacity
- ton
Shipping
Weight
(Ib)
(kg)
Compressor
Quantity
Type
Refrigerant
Refrigerant
Quantity
(Ib)
Quantity
(kg)
Refrigerant
Metering
Device
Orofice
OD(in)
(mm)
Outdoor
Coil
Rows...
Fins/in,
facearea
(sq.ft.)
Outdoor
Fan
Nominal
Airflow
(cfm)
Diameter
(in.)
Diameter
(mm)
Motor
hp
Motor
(rpm)
Indoor
Coil
Rows...
Fins/in,
facearea
(sq.ft.)
Indoor
Blower
Nominal
Airflow
(cfm)
Size
(in.)
Size
(mm)
Motor
hp
Furnace
Section*
Burner
Orifice
Natural
Gas
Qty...Drill
Size
Propane
GasQty...Drill
Size
HighPressure
Switch
(psig)
Cutout
Reset
(Auto)
Lossof-Charge/Low
Pressu
re
Switch
(psig)
Cutout
Reset
(Auto)
Return
AirFiltersl-$
disposable
(in)
(mm)

Table

1 - Physical

42080
3.5
472
214

42090
3.5
472
214

Data - Unit 48VT-A
48090
4
460
209

Cont'd)

48115
4
460
209

48130
4
460
209

80090
5
506
230

80115
5
506
230

80130
5
506
230

12.5
5.7

15.2
6.9

0.049 (2)
1.24 (2)

1
Scroll
R- 410A
11.3
5.1

11.3
5.1

0.040 (2)
1.02 (2)

12.5
5.7

Indoor
0.040 (2)
1.02 (2)

TXV, Outdoor
0.040 (2)
1.02 (2)

Dual Accuraters
0.040 (2)
0.049 (2)
1.02 (2)
1.24 (2)

2...21

17.5

23.3

31 O0
26

3500
26

660
1/5

660
1/4

(81o)

3...17
4.7

1400
11 xlO
279 x 254

3/4

2...38
2...53

3...38
3...53

(81o)

3...17
5.6

1600
11 xlO
279 x 254
1

3...38
3...53

(81O)

3...17
5.6

(81O)
3...17
5.6

1600
11 xlO
279 x 254

1750
11 xlO
279 x 254

3...33
3...51

24x30x1
610x762x25

(81o)

3...31
3...49
650 +/420 +/-

15
25

20 +/45 +/-

5
10

3...38
3...53

3...33
3...51

(81O)
3...17
5.6
1750
11 xlO
279 x 254
1

3...31
3...49

24x36x1
610x914x25

,,7_

Cut along
'V" grooves

"_4

Drill
places

L)
I

Return

Horizontal

Duct Panels

Duct Covers

Cut along

A09076

"V" grooves N

Flex up & down
to remove

I-.IE

,IAIEIxli
: I sl

AI Cl

','_

Itl HI,:

Cut along "V"
groove, teeth
facing up

--Drill

Basepan
Downflow

(Vertical)

Basepan
Downflow

Supply
_
Knockout

3 places

Supply Duct Panels

(Vertical)
Return
Knockout

Drill 2 places
A09077

Fig. 8 - Supply

and Return

Duct Opening

Cut along
"V" grooves
Return & Supply Duct Panels from

Underside of Base (Alternate Method)
A09420
Fig.
Table
NOMINAL
IRON

2 - Maximum

Gas

INTERNAL

(Downflow)

Discharge

Duct

Knockouts

Capacity*

LENGTH OF PIPE, FT (m)t

DIAMETER
10
PIPE,
(IN.)
(3.0)
(IN.)SIZE
1/2
.622
175
3/4
.824
360
1
1.049
680
1 - 1/4
1.380
1400
1 - 1/2
1.610
2100
* Capacity of pipe in cu ft of gas per hr for
and the NFGC NFPA 54/ANSI Z 223.1.
1-This length includes an ordinary number

20
(6.1)

30
(9.1)

40
(12.2)

50
(15.2)

80
(18.3)

70
(21.3)

120
97
82
73
66
250
200
170
151
138
465
375
320
285
260
950
770
600
580
530
1460
1180
990
900
810
gas pressure of 0.5 psig or less. Pressure drop of

80
(24.4)

90
(27.4)

61
57
125
118
240
220
490
460
750
690
0.5-IN. W.C. (based

53
110
205
430
650
on a 0.60

100
(30.5)

125
(31.1)

150
(45.7)

50
44
103
93
195
175
400
360
620
550
specific gravity gas).

175
(53.3)

40
-84
77
160
145
325
300
500
460
Refer to Table 2

of fittings.
Table

HEATING INPUT

Flow

9 - Vertical

3 - Heating

GAS SUPPLY
Naturalt

Inputs

PRESSURE

MANIFOLD

(IN. W.C.)

PRESSURE

(BTUH)

NUMBER OF
ORIFICES
Min

Max

Min

Max

Natural1-

40,000

4.0

13.0

11.0

13.0

3.2-3.8

Propane*t
10.0-11.0

60,000

4.0

13.0

11.0

13.0

3.2-3.8

10.0-11.0

90,000

4.0

13.0

11.0

13.0

3.2-3.8

10.0-11.0

115,000

4.0

13.0

11.0

13.0

3.2-3.8

130,000

4.0

13.0

11.0

13.0

3.2-3.8

10.0-11.0
10.0-11.0

(IN. W.C.)

Propane*t

*When a unit is converted to propane, different size orifices must be used. See separate, natural-to-propane
conversion kit instructions.
1-Based on altitudes from sea level to 2000 ft (610 m) above sea level. In the U.S.A. for altitudes above 2000 ft (610 m), reduce input rating 4 percent for each
additional 1000 ft (305 m) above sea level. In Canada, from 2000 ft (610 m) above sea level to 4500 ft (1372 m) above sea level, derate the unit 10 percent.

200
(61.0)
-72
135
280
430

6. Adequately

insulate

and weatherproof

all ductwork

located

outdoors.
Insulate
ducts passing
through
unconditioned
space, and use vapor barrier in accordance
with latest issue
of Sheet

Metal

and Air Conditioning

Contractors

National

Association
(SMACNA)
and Air Conditioning
Contractors
of America
(ACCA)
minimum
installation
standards
for
heating and air conditioning
systems. Secure all ducts to
building
7. Flash,

low-voltage
location).

Single

phase units:

1. Run the high-voltage
control box.

weatherproof,
structure
practices.

and vibration-isolate
in accordance

Step 10 -- Install Electrical

all openings

with local codes

2. Connect

and good

ground

Connections

4. Connect

field

5. Connect
HAZARD

Failure to follow this warning
or death.
The unit cabinet must
electrical ground. This
wire connected
to the
compartment,
or conduit
installed in accordance

Three-phase

could result in personal

iniury

have an uninterrupted,
unbroken
ground may consist of an electrical
unit ground screw in the control
approved for electrical ground when
with NEC, NFPA 70 National Fire

2. Connect

1. Make

all electrical

NFPA
70
governing
connections
C22.1

connections

in accordance

Code

local codes. Refer to unit wiring

field

compressor
5. Connect

to the unit

sure

that

operating
3-phase

high-voltage

ground

connection.

to black

wire

to the line side

on connection

11 of the

field wire L3 to yellow

wire on connection

13 of

contactor.

field wire L2 to blue wire from compressor.

Procedures

for

208-V

Operation

Part 1 and applicable
diagram.

power

to unit

HAZARD

this warning

could result in personal

iniury

black wire from transformer (3/16 in.) terminal marked 230 to
terminal
marked 200. This retaps transformer
to primary
voltaye of 208 vac.

is within

voltage range indicated on unit rating plate. On
units, ensure
phases are balanced
within
2

not

damage

internal

components

any panel to mount

Hi,h-Voltage
When

lead to chassis

lead into the

Make sure the power supply to the unit is switched OFF before
making any wiring changes. Tag the disconnect switch with a
suitable warning label. With disconnect
switch open, move

ELECTRICALSHOCK

Failure to follow
or death.

4. Insulate low-voltage
wires for highest voltage contained
within conduit when low-voltage
control wires are in
same conduit as high-voltage
wires.

through
etc.

23 of

contactor.

Failure to follow
or death.

with NEC

percent. Consult local power company for correction
improper voltage and/or phase imbalance.

5. Do

11 of the

wire on connection

(L1, L2, L3) and ground

ELECTRICALSHOCK

2. Use only copper conductor
for connections
between
field-supplied
electrical disconnect
switch and unit. DO
NOT USE ALUMINUM
WIRE.
3. Be

on connection

HAZARD

may result in damage

Electrical

wire

to the line side

contactor.

ground

4. Connect

(latest edition)
and local electrical
codes
such
wiring.
In Canada,
all electrical
must be in accordance
with CSA standard

Canadian

to black

the

connection.

3. Locate the black and yellow wires connected
of the contactor.

Special

Failure to follow this caution
being installed.

ground

lead into

units:

6. Connect

DAMAGE

1. Run the high-voltage
control box.

Association
(latest edition) (in Canada, Canadian
Code CSA C22.1) and local electrical codes.

COMPONENT

lead to chassis

field wire L2 to yellow

the compressor

UNIT

L2) and ground

contactor.

the compressor
ELECTRICALSHOCK

(L1,

3. Locate the black and yellow wires connected
of the contactor.

compressor

Protection
Electrical

are used (See Fig. 2 and 3 for acceptable

See unit wiring label (Fig. 15 and 16) and Fig. 10 for reference
when making
high voltage connections.
Proceed as follows to
complete the high-voltage
connections
to the unit.

structure.

building
building

entry points

routing

electrical

when

drilling

hardware,

conduit,

unit and install lockout

could result in personal

leads into unit, use only copper

a separate
disconnect

iniury

Control

Voltage

tag.

Connections

Do not use any type of power-stealing
problems may result.
wire between

disconnect
and unit. The high voltage leads should be in a conduit
until they enter the duct panel; conduit
termination
at the duct
panel must be watertight.
The unit
must
have
field-supplied,
waterproof

this warning

Before making any wiring changes, make sure the gas supply
is switched off first. Then switch off the power supply to the

Connections
power

HAZARD

electrical
service
with
a
switch mounted at, or within

Use

no.

18 American

Wire

Gage

(AWG)

thermostat.
color-coded,

Unit

control
insulated

(35°C minimum)
wires to make the control voltage connections
between
the thermostat
and the unit. If the thermostat
is located
more than 100 ft (30.5 m) from the unit (as measured
control voltage wires), use no. 16 AWG color-coded,
(35 ° C minimum) wires.

along the
insulated

sight from, the unit. Refer to the unit rating plate, NEC and local
codes for maximum
fuse/circuit
breaker size and minimum
circuit

Locate the seven (eight on 3-phase)
low voltage thermostat leads
in 24 volt splice box. See Fig. 10 for connection
diagram. Run the

amps (ampacity)

low-voltage
leads from the thermostat,
through the control
inlet hole grommet (Fig. 2 and 3), and into the low-voltage
box. Provide
a drip loop before running wires through

The field-supplied

for wire sizing.
disconnect

unit over the high-voltage

switch

box may be mounted

inlet hole when

the standard

on the

power

and

Secure
13

and strain

relief all wires so that they do not interfere

wiring
splice
panel.
with

operation
of unit. A gray wire
connection to an economizer.

HIGH VOLTAGE

POWER

do,,.

LEADS

is standard

on 3-phase

unit

for

Transformer

Protection

The transformer is of the energy-limiting
type. It is set to withstand
a 30-sec. overload or shorted secondary
condition. If an overload
or short is present, correct overload condition and check for blown
fuse on gas control board or Interface Fan Board. Replace
required with correct size and rating.

(SEE UNIT WIRINGI
LABEL)
_

fuse as

PRE-START-UP
E__

EQUIP GR
FIELD-SUPPLIED
FUSED
DISCONNECT

CONTROL

BOX
I

Co-

.,,YEL_._),.,,, ,_

IOIO-

LOW VOLTAGE
POWER LEADS
(SEE UNIT
WIRING LABEL)

- "l O,,.
io1oio=

@
®
@

_W
H_..TLW_I
).D.
GROG2 0.
RED,

R)..

to follow this warning

1. Follow

THERMOSTAT
(TYPICAL)

3_Phast

3. Do

Only

safety

when checking

to unit unless
secured.

SHOCK

HAZARD

could result in personal

iniury,

damage.

2. Do not operate

(DH)_,,

ELECTRICAL

recognized

goggles

EXPLOSION,

Failure

death or property

.BR_C) 9.

BLU

FIRE,

practices

and wear

protective

or servicing

refrigerant

system.

compressor

or provide

compressor

not

remove

electrical

sources

terminal

compressor

any electric

cover

terminal

are disconnected

power

is in place and
cover

until

all

and tagged.

SPLICE BOX

4. Relieve and recover all refrigerant
from system before
touching or disturbing
anything inside terminal box if
refrigerant
leak
is suspected
around
compressor
terminals.

A09067

Fig. 10 - High

Connections

Setting-Thermidistat

Balance
Point
Thermostat
BALANCE
temperature

and Control-Voltage

or Hybrid

5. Never
attempt
to repair
soldered
refrigerant system is under pressure.

POINT
TEMPERATURE-The
"balance
point"
is a setting which affects the operation
of the heating

6. Do

not

use torch

to remove

mode. This is a field-selected
input temperature
(range 5 to 55°F)
(-15 to 12°C) where the Thermidistat
or dual fuel thermostat will

contains oil and refrigerant
To remove a component,

monitor outdoor air temperature
and decide whether to enable or
disable the heat pump. If the outdoor
temperature
is above the
"balance point", the heat pump will energize first to try to satisfy

proceed

the indoor

temperature

demand.

If the heat pump

does not make a

to maintain

2. Economic

Balance

proper

indoor

Temperature:

d. Carefully
necessary.
flame.
Proceed

as follows

1. Remove

shipped

pump is the most cost efficient to operate, and below this
point the furnace is the most cost efficient to operate. This

broken

of the furnace
and heat
operation, the heat pump

pump.
should

3. Comfort
operating

Balance
below

b. Inspect

and it involves
as well as the

Temperature:
When the heat
this point, the indoor
supply

operate

and the

prepare

the

tubing

unit

for

initial

(see Fig. 19).

follow
instructions
and INFORMATION

on
all
WARNING,
labels attached
to, or

inspections:

for shipping

and handling

damages

lines, loose parts, disconnected
for oil at all refrigerant

tubing

oil generally

wires,

such as
etc.

connections
indicates

solution. If a refrigerant leak is detected,
for Refrigerant
Leaks section.

pump is
air feels

in order

tubing with
from unit.

and

c. Leak test all refrigerant tubing connections
using
electronic leak detector, halide torch, or liquid-soap

d. Inspect all field- and factory-wiring
sure that connections
are completed

uncomfortable
(i.e. too cool). This is purely subjective
and
will depend on the homeowner's
idea of comfort. Below
this temperature
the gas furnace should
satisfy the desire for indoor comfort.

and

on unit base. Detecting
refrigerant leak.

For the most
operate above

this temperature
(assuming it has sufficient capacity)
furnace should operate below this temperature.

system

with, unit.

a. Inspect

efficiency
economical

to inspect

3. Make the following
the heat

can be somewhat
complicated
to determine
knowing
the cost of gas and electricity,

and

unsweat remaining
tubing stubs when
Oil can ignite when exposed to torch

access panels

2. Read
and
CAUTION,

temperature.
this point,

goggles

start-up:

is a point where the
capacity to keep up

Above

System

power to unit and install lockout

c. Cut component
connecting
cutter and remove component

with the indoor temperature
demand because of declining
outdoor temperature.
At or below this point, the furnace is
needed

component.

under pressure.
wear protective

tag.
b. Relieve and reclaim all refrigerant
from
using both high- and low-pressure
ports.

"balance point", the heat pump will not be allowed to operate (i.e.
locked out), and the gas furnace will be used to satisfy the indoor
temperature.
There are three separate concepts which are related to

1. Capacity Balance Temperature:
This
heat pump cannot provide
sufficient

any

while

as follows:

a. Shut off electrical

sufficient
improvement
within a reasonable
time period (i.e. 15
minutes), then the gas furnace will come on to satisfy the indoor
temperature
demand.
If the outdoor
temperature
is below the

selecting the final "balance point" temperature.
Read each of the
following
carefully
to determine
the best "balance
point" in a
hybrid installation:

connection

e. Ensure wires do not touch
sheet metal edges.

f. Inspect
handling,

refrigerant

coil fins. If damaged
carefully

straighten

during

see the Check

connections.
and tight.
tubing
shipping

or sharp
and

fins with a fin comb.

c. HEAT

PUMP

HEATING

Outdoor temperature
thermostat.

MODE

above balance

point setpoint

FIRE,EXPLOSION
HAZARD
(1.) On a call for heating, terminals "Y" and "G" of the
Hybrid thermostat are energized. The "Y" signal is
Failure
tofollowthiswarning
could
result
inpersonal
injury,
sent to the Defrost Board (DB) terminal "Y". The
death
orproperty
damage.
DB has a built in five minute anti-short
cycle timer
Donotpurge
gassupply
intothecombustion
chamber.
Donot
which will not allow the compressor
to restart
useamatch
orother
open
flame
tocheck
forgasleaks.
Usea
before the time delay has expired.
commercially
available
soap
solution
made
specifically
for
thedetection
ofleaks
tocheck
allconnections.
(2.) "T2" energizes the compressor
contactor via the
High Pressure Switch (HPS) and Low Pressure
4.Verify
thefollowing
conditions:
Switch (LPS). The compressor
and outdoor fan
a.Make
sure
gaslineisfreeofair.Before
lighting
theunit
start. Thermostat
"G" energizes the Interface Fan
forthefirsttime,
perform
thefollowing
withthegas
Board terminal "G". The blower motor is energized
valve
inthe"OFF"position:
through contacts of the IFB.
NOTE:If thegassupply
pipewasnotpurged
before
connecting
(3.) When the thermostat removes the "Y" and "G"
theunit,it willbefullofair.It isrecommended
thattheground
calls, the compressor
contactor and outdoor fan are
jointunionbeloosened,
andthesupply
linebeallowed
topurge
de-energized.
The evaporator
motor is de-eneruntiltheodorof gasis detected.
Never
purge
gaslinesintoa
gized after a 90 sec. delay.
combustion
chamber.
Immediately
upondetection
of gasodor,
d. GAS HEATING MODE
retighten
theunion.
Allow5minutes
toelapse,
thenlightunit.
Outdoor temperature
below balance point setpoint of
thermostat.
b.Make
sure
thatcondenser-fan
blade
iscorrectly
positioned
infanorifice.
Leading
edge
ofcondenser-fan Heating Sequence of Operation
blade
should
be1/2in.(12mm)maximum
fromfan
(See Fig. 15 and 16 and unit wiring label.)
orifice.
On a call for heating, terminal W of the thermostat
is energized,
c.Make
sure
thatairfilter(s)
isinplace.
starting the induced-draft
motor. When the pressure switch senses
d.Make
sure
thatcondensate
drain
trapisfilledwithwater
that the induced-draft
motor is moving sufficient combustion
air,
toensure
proper
drainage.
the burner sequence
begins. This function
is performed
by the
e.Make
sure
thatalltoolsandmiscellaneous
loose
parts
integrated
gas unit controller (IGC). The indoor (evaporator)-fan
have
been
removed.
motor is energized
45 sec after flame is established.
When the
START-UP
Step 1 1

Check

Proceed as follows
charge the unit:

for Refrigerant
to locate

and repair

Leaks
a refrigerant

1. Locate leak and make sure that refrigerant
has been relieved
and reclaimed
from
low-pressure
2. Repair
NOTE:
opened

Install

thermostat
is satisfied
firing and the indoor
leak

and to

system pressure
both highand

ports.

leak following
a bi-flow

Refrigerant

Service

filter drier whenever

procedures.

the system

has been

for repair.

3. Add a small charge
and leak-test unit.

of R-410A

refrigerant

vapor

to system

4. Recover refrigerant from refrigerant system and evacuate
500 microns if no additional leaks are not found.

and W is de-energized,
(evaporator)
fan motor

45-sec time-off delay. Please note that the IGC has the capability
to automatically
reduce the indoor fan motor on delay and increase
the indoor fan motor off delay in the event of high duct static
and/or

partially-clogged

NOTE:
An LED
the control board
located
normal

filter.

(light-emitting
to monitor

Start-up

Heating

UNIT

charge.

Step 2 1 Unit Sequence of Operation
48VT-A Sequence of Operation

COMPONENT

DAMAGE

devices
the

MODE

(1.) If indoor temperature
is above temperature
set
point thermostat closes circuits R to G, R to Y and
R to O-The

unit delivers

cooling

airfow.

when operating

HAZARD

may result in damage

Complete the required procedures
section before starting the unit.

FAN

(1.) Thermostat closes circuit R to G energizing
blower motor for continuous
fan.

and Make Adjust-

Failure to follow this caution
being installed.

b. COOLING

diode) indicator is provided on
operation.
The control
board is

by removing the burner access panel (see Fig. 19). During
operation, the LED is continuously
on.

Step 3 1
ments

5. Charge unit with Puron (R-410A)
refrigerant,
using an
electronic
scale. Refer to unit rating plate for required

a. CONTINUOUS

the burners stop
shuts off after a

to the unit

given in the Pre-Start-Up
Do not jumper any safety

the unit.

Complete
the required
procedures
given in the Pre-Start-Up
section before starting the unit. Do not jumper any safety devices
when
operating
properly
aligned.

the unit.
Unstable

orifices

in the manifold

the lighting

are misaligned.

instructions

label (located on the inside
heating section.

Make sure that burner
orifices
are
operation
nay occur when the burner
on the heating

of the control

access

section
panel)

operation
to start the

NOTE:

Make

gas piping

sure that gas supply

has been checked

has been purged,

and that all

on natural

for leaks.

specific

gas with a heating

gravity,

value of 1025 Btu/ft 3 at 0.60

or propane

Btu/ft 3 at 1.5 specific

gas with a heating

value of 2500

gravity.

IN THE U.S.A.:
The

input

reduced

rating

for altitudes

above

2,000

ft (610

m) must

by 4% for each 1,000 ft (305 m) at_ove see level.

For installations
plate.

below

2,000

ft (610

m), refer to the unit rating

For installations
above 2,000 ft (610 m) nmltiply the input by on
the rating plate by the derate multiplier in Table 4 for correct input
rate.
Table
ALTITUDE

4 - Altitude

FT (M)

Derate

PERCENT

1,00

8-12

0,90

12-16

0,86

16-20

0,82

20-24

0.78

24-28

0.74

28-32

0.70

32-36

0,66

36-40

0.62

(0-610)

"Manifold

3001-4000
(315-1219)

A07679

4001-5000

Fig. 11 - Burner

for U.S.A.*

DERATE MULTIPLIER
FACTOR1-

OF DERATE

0-2000

2001-3000*
(610-914)

Multiplier

Assembly

(1220 - 1524)
5001-6000

BURNER FLAME

(1524-1829)
6001-7000
(1829 - 2134)
7001-8000
(2134-2438)
8001-9000
(2439-2743)

9001-10,000
(2744-3048)

In Canada see Canadian Altitude Adjustment.
1-Derate multiplier factors are based on midpoint

°'°

The
C99021

Fig. 12 - Monoport
Check

Heating

access

1. Place

rating

for altitudes

from

2,000

sea level must be derated
Station or Dealer.

to 4,500

fl (610

m to

10% by an authorized

90,000

Btu/hr

Input Furnace

Installed

at 4300 fl (1311 m).

Control
Furnace
Input
Sea Level

as
of

Rate

g0,000

Derate
Factor

Multiplier

0.g0

Furnace
Input Rate
Installation
Altitude

81,000

panel):

room

position

input

1372 m) above
Gas Conversion
EXAMPLE:

Burner

Start and check the unit for proper heating control operation
follows (see furnace lighting instructions
located on the inside
the control

altitude for altitude range.

IN CANADA:

thermostat

SYSTEM

and the fan switch

2. Set the heating

switch

is placed in AUTO

temperature

control

the

HEAT

position.

of the thermostat

When the gas supply being used has a different heating value or
specific gravity, refer to national and local codes, or contact your
distributor

to deternfine

the required

orifice size.

above

room temperature.
3. The induced-draft

motor

will start.

4. On a call for heating, the main burner should light within 5
sec. of the spark being energized. If the burners do not light,
there is a 22-sec.
delay before another
burners still do not light, this sequence
burners do not light within
for heat, there is a lockout.
24-v power to W.
5. The evaporator

[]NIT

Do Not redrill an orifice. Improper drilling (burrs,
out-of-round
holes, etc.) can cause excessive burner noise
and nfisdirection of burner flame. If orifice hole appears
damaged or it is suspected to have been redrilled, check
orifice hole with a numbered drill bit of correct size.

15 nfinutes from the initial call
To reset the control, break the
has

been established.
The evaporator
fan will turn off 45 sec.
after the thermostat has been satisfied. Please note that the
integrated
gas unit controller
(IGC) has the capability
to
automatically
reduce the evaporator
"ON" delay and increase the evaporator "OFF" delay in the event of high duct
static and/or
Check

Gas

partially-clogged

filter.

Input

Check gas input and manifold
pressure
Table 3). If adjustment is required proceed

after unit start-up
as follows:

• The rated gas inputs shown in Table 3 are for altitudes
level to 2000

(See

from sea

ft (610 m) above sea level. These inputs are based

HAZARD

Failure to follow this caution may result in reduced unit
and/or component life.

5-sec. try. If the
is repeated.
If the

fan will turn on 45 sec. after the flame

DAMAGE

Adiust

Gas Input

The gas input to the unit is determined by measuring the gas flow
at the meter or by measuring the manifold pressure. Measuring the
gas flow at the meter is recommended for natural gas units. The
manifold pressure must be measured to determine the input of
propane gas units.
Measure

Gas Flow (Natural Gas []nits)

Minor ac[iustment to the gas flow can be made by changing the
manifold pressure. The manifold pressure must be maintained
between 3.2 and 3.8 IN. W.C.
16

4. Turn off gas supply to unit. Remove manometer from
pressure tap and replace pipe plug on gas valve. (See Fig.
11.) Turn on gas to unit and check for leaks.
Measure Manifold Pressure (Propane Units)

REGULATOR

PLASTIC

ON/OFF SWITCH

Refer to propane kit installation instructions for properly checking
gas input.

REGULATOR SPRING
(PROPANE - WHITE)
(NATURAL - SILVER)

NOTE: For installations below 2,000 fl (610 m), refer to the unit
rating plate for proper propane conversion kit. For installations
above 2,000 fl (610 m), contact your distributor for proper propane
conversion kit.

GAS PRESSURE
INLET
PRESSURE

TAP

Check

MANIFOLD

A07751

Fig. 13 - Single-Stage Gas Valve
If larger adjustments are required, change main burner orifices
following

the recommendations

of national

and

local

codes.

NOTE:
All other appliances that use the same meter must be
turned off when gas flow is measured at the meter.
Proceed as follows:
1. Turn off gas supply to unit.
2. Remove pipe plug on manifold (See Fig. 11) and connect
manometer. Turn on gas supply to unit.
3. Record number of seconds for gas meter test dial to make
one revolution.
4. Divide number of seconds in Step 3 into 3600 (number of
seconds in one hr).
5. Multiply result of Step 4 by the number of cubic feet (cu fl)
shown for one revolution of test dial to obtain cubic feet (cu
fl) of gas flow per hour.
6. Multiply result of Step 5 by Btu heating value of gas to
obtain total measured input in Btuh. Compare this value
with heating input shown in Table 3 (Consult the local gas
supplier if the heating value of gas is not known).
EXAMPLE: Assume that the size of test dial is 1 cu fl, one
revolution takes 32 sec, and the heating value of the gas is 1050
Btu/fl 3. Proceed as follows:
1. 32 sec. to complete one revolution.
2. 3600 + 32 = 112.5.
3. 112.5 x 1 =112.5 f13of gas flow/hr.
4. 112.5 x 1050 = 118,125 Btuh input.
If the desired gas input is 115,000 Btuh, only a minor change in the
manifold pressure is required.
Observe manifold pressure and proceed as follows to adjust gas
input:
1. Remove regulator cover screw over plastic adjustment
screw on gas valve (See Fig. 13).
2. Turn plastic adjustment screw clockwise to increase gas
input, or turn plastic adjustment screw counterclockwise to
decrease input (See Fig. 13). Manifold pressure must be
between 3.2 and 3.8 IN. W.C.

Burner

With control access panel (see Fig. 19) removed, observe the unit
heating operation. Watch the burner flames to see if they are light
blue and soft in appearance, and that the flames are approximately
the same for each burner. Propane will have blue flame (See Fig.
12). Refer to the Maintenance section for information on burner
removal.
Normal

Operation

An LED (light-emitting
diode) indicator is provided on the
integrated gas unit controller (IGC) to monitor operation. The IGC
is located by removing the control access panel (see Fig. 19).
During normal operation, the LED is continuously on (See Table 5
for error codes).
Airflow

and Temperature

Table 10 shows the approved temperature rise range for each
heating input, and the air delivery cfm at various temperature rises
for a given external static pressure. The heating operation airflow
must produce a temperature rise that falls within the approved
range.
Refer to Indoor Airflow and Airflow Adjustments section to adjust
heating airflow when required.
Limit Switches
Normally closed limit switch (LS) completes the control circuit.
Should the leaving-air temperature rise above the maximum
allowable temperature, the limit switch opens and the control
circuit "breaks." Any interruption in the control circuit instantly
closes the gas valve and stops gas flow to the burners. The blower
motor continues to run until LS resets.
When the air temperature at the limit switch drops to the
low-temperature setting of the limit switch, the switch closes and
completes the control circuit. The direct-spark ignition system
cycles and the unit returns to normal heating operation.
Table
STATUS
Normal
Limit
Flame

Pressure

DAMAGE

HAZARD

Failure to follow this warning could result in personal
iniury or death and/or property damage.
Unsafe operation of the unit may result if manifold pressure
is outside this range.

3. Replace regulator cover screw on gas valve (See Fig. 13).

5 - LED Indications

CODE

LED INDICATION

Operation

No Power Hardware

Ignition

AND UNIT

Rise

The heating section for each size unit is designed and approved for
heating operation within the temperature-rise range stamped on the
unit rating plate.

Four Consecutive

FIRE

Flame

Switch
Sense

Failure

Off

Fault

2 Flashes

Fault

3 Flashes

Limit

Switch

Lockout

Fault

5 Flashes

Fault

6 Flashes

Switch

Faults

4 Flashes

Rollout

Switch

Fault

7 Flashes

Internal

Control

Fault

8 Flashes

Temporary

1 hr auto

reset I

9 Flashes

NOTES:
1 .This code indicates an internal processor fault that will reset itself in one
hr. Fault can be caused by stray RF signals in the structure or nearby. This
is a UL requirement.
2, LED indicates acceptable operation. Do not change ignition control
board,
3. When W is energized the burners will remain on for a minimum of 60 sec.
4. If more than one error mode exists they will be displayed on the LED in
sequence.

Rollout

Switch

The function of the rollout
the event of flame rollout.
burners.

When

switch is to close the main gas valve in
The switch is located above the main

the temperature

at the rollout

switch

reaches

the

maximum
allowable temperature,
the control circuit trips, closing
the gas valve and stopping
gas flow to the burners. The indoor

Cooling

Complete

procedures

the

required

and

given

in the

Pre-Start-Up

1. Place room thermostat
Observe
that blower

cooling

control

operation

2. Place SYSTEM switch in COOL position and FAN switch
in AUTO
position.
Set cooling
control
below
room
temperature.
Observe that compressor,
condenser
fan, and
evaporator
blower motors start. Observe that cooling cycle
shuts down when control setting is satisfied.
fan will continue to run for 90 sec.

direction

Three-phase,

oriented.

compressor

Unit

3-phase

5 minutes,

power

rotation.

protector

leads

When

compressor

to the

turning

suction

The evaporator

compressors

checked

power lead orientation.

the internal

3-phase

scroll

must

units

ensure

unit

must

If not corrected

backwards,

and discharge

reversed

the

pressures

are

proper
within

will shut off the compressor.

The

to correct

difference

may result in unit damage.
charge,
an indicated
charge must always be

between

will be near zero.

service fittings.

a. Outdoor ambient-air temperature (°F (°C) db).
b. Liquid line temperature (°F (°C).

SYSTEM
switch in OFF position.
motor starts when FAN switch
is

placed in ON position and shuts down when FAN switch
placed in AUTO position.

IMPORTANT:

this caution

2. []sing hoses with valve core depressors, attach low- and
high-pressure
gauge hoses to low- and high-pressure
service fittings, respectively.
3. Start unit in Cooling Mode and let unit run until system
pressures stabilize.
4. Measure and record the following:

ChecMng Cooling Control Operation
for proper

to follow

1. Remove caps from low- and high-pressure

outdoor
temperature
is below 40°F
(4.4°C) (unless accessory
low-ambient
kit is installed). Do not rapid-cycle
the compressor.
Allow 5 minutes between on cycles to prevent compressor
damage.

the unit

Failure

Proceed as follows:

section before starting the unit. Do not jumper any safety devices
when operating
the unit. Do not operate the compressor
when the

Start and check
follows:

HAZARD

very minimal.
If a substantial
adjustment
is indicated,
an
abnormal condition exists somewhere
in the cooling system,
such as insufficient airflow across either coil or both coils.

Adjust-

Make

DAMAGE

When
evaluating
the refrigerant
adjustment
to the specified factory

(evaporator)
fan motor (IFM) and induced draft motor continue to
run until switch is reset. The IGC LED will display FAULT CODE
7.

Step 4 -- Start-up
ments

[]NIT

c. Discharge (high-side) pressure (psig).
d. Suction (low-side) pressure (psig) (for reference only).
5. Using "Cooling Charging Charts," compare outdoor-air
temperature(°F (°C) db) with the discharge line pressure
(psig) to determine desired system operating liquid line
temperature (See Fig. 17).
6. Compare actual liquid line temperature with desired liquid
line temperature. Using a tolerance of - 2°F (-1.1°C), add
refrigerant if actual temperature is more than 2°F (1.1°C)
higher than proper liquid line temperature, or remove
refrigerant if actual temperature is more than 2°F (1.1°C)
lower than required liquid line temperature.
NOTE:
If the problem causing the inaccurate readings is a
refrigerant leak, refer to the Check for Refrigerant Leaks section.
Indoor

Airflow

and Airflow

Adjustments

ChecMn_ and Adiustin_ Refrigerant Charge
The refrigerant
system is fully charged with Puron®
(R-410A)
refrigerant and is tested and factory sealed. Allow system to operate
a minimum
NOTE:

of 15 minutes

Adjustment

the unit is suspected
charge.
The

charging

label

before

checking

of the refrigerant
of not having
and

the

or adjusting

charge
the proper

tables

temperatures
and pressures
in cooling
charging label is attached to the inside

charge.

is not required

shown

Puron®
refer

[]NIT

HAZARD

Failure to follow this caution may result in unit damage.

(R-410A)
to

OPERATION

unless

For cooling operation, the recommended airflow is 350 to
450 cfm for each 12,000 Btuh of rated cooling capacity. For
heating operation, the airflow must produce a temperature
rise that falls within the range stamped on the unit rating
plate.

system

mode only. A refrigerant
of the compressor
access

panel (see Fig. 19). The chart
includes the required liquid line
temperature
at given discharge line pressures and outdoor ambient
temperatures.
An accurate
thermocoupleor thermistor-type
thermometer,
and a
gauge manifold
are required when using the subcooling
charging

NOTE:

Be sure that all supply-and

free from obstructions,

method for evaluating the unit charge. Do not use mercury or small
dial-type
thermometers
because they are not adequate for this type
of measurement.

and adjusted

ELECTRICALSHOCK
Failure to follow
iniury or death.

return-air

grilles

are open,

properly.

HAZARD
this warning

could

result

in personal

Before making any indoor wiring adjustments,
shut off gas
supply. Then disconnect
electrical power to the unit and
install lockout tag before changing blower speed.

This unit has independent
fan speeds for gas heating and cooling.
In addition, this unit has the field-selectable
capability to run two
different
18

cooling

fan speeds:

A normal

cooling

fan speed (350~400

CFM/Ton) and an enhanced dehumidification fan speed (As low as
320 CFM/Ton) for use with either a dehumidistat or a thermostat
that supports dehumidification.

Use of the dehumidification
cooling
fan speed
either a 24 VAC dehumidistat
or a thermostat

This unit is factory-set up for use with a single cooling fan speed.
The cooling speed is marked "LOW" on the interface fan board
(IFB) (Fig. 14) . The factory-shipped settings are noted in Table
10. There are 3 additional speed tap wires available for use in
either gas heating or cooling (For color coding on the indoor fan
motor leads, see Table 6). The additional 3 speed tap wires are
shipped loose with vinyl caps and are located in the control box,
near the interface fan board (IFB) (Fig. 14).

dehumidification
control must open the control circuit on humidity
rise above
the dehumidification
set point.
Dehumidification
controls are available with the reverse logic; these must not be
used.

Gas Heating

Fan Speed

control

1. Remove
2. Determine
application.

Set-up

2. Remove the current speed tap wire from the "LOW"
terminal on the interface fan board (IFB) (Fig. 14) and place
vinyl cap over the connector on the wire,
3. Connect the desired speed tap wire to the "LOW" terminal
on the interface fan board (IFB).
Speeds

3. Remove

open

the "LOW"

case, the

terminal

(IFB) (Fig. 14).

correct normal cooling fan speed for unit and
Add the wet coil pressure drop in Table 8 to

the vinyl

cap off of the

desired

speed

airflow
cooling
tap wire

4. Refer to airflow tables (Table 10) to determine
allowable
speeds for the dehumidification
cooling fan speed. In Table
10, speeds that are not allowed for dehumidification
cooling
are shaded.
5. Remove

the vinyl

cap off of the

desired

speed

tap wire

(Refer to Table 6 for color coding) for the dehumidification
cooling fan speed and place desired speed tap wire on the
"LOW" connection
on the interface board (IFB).
Verify
that static pressure is in the acceptable range for the speed
tap to be used for dehumidification
cooling.
6. Use any spare
wires.
NOTE:

vinyl

For heat pump

plugs

operation,

to 450 CFM for each 12,000

Continuous
When

to cap any unused
the recommended

Btuh of rated cooling

speed

tap

airflow is 350
capacity.

Fan Operation

the DEHUM

feature

is not used,

the continuous

fan speed

will be the same as cooling fan speed. When the DEHUM feature
is used, the continuous
fan will operate on IFB "LOW" speed
when the DH control lead is not energized, or IFB "HIGH"
when the DH lead is energized (see Fig. 14).
Table

6 - Color

Coding

for Indoor

Fan

Black = High Speed
Orange

must

tap wire from

fan board

In either

(Refer to Table 6 for color coding) for the normal cooling
fan speed and place desired speed tap wire on "HIGH" on
the interface board.

Set-up (Dehumidification

IMPORTANT:
Dehumidification
control
circuit on humidity rise above set point,

connection.

the system static to determine
the correct cooling
speed in Table 10 that will deliver the nominal
airflow as listed in Table 1 for each size.

2. Remove the current speed tap wire from the "GAS HEAT"
terminal on the interface fan board (IFB) (Fig.14) and place
vinyl cap over the connector on the wire.
3. Connect the desired speed tap wire to the "GAS HEAT"
terminal on the interface fan board (IFB).
Single Cooling Fan Speed Set-up (Dehumidification
feature not used)
To change cooling speed:
1. Remove the vinyl cap off of the desired speed tap wire
(Refer to Table 6 for color coding). Add the wet coil
pressure drop in Table 8 to the system static to determine the
correct cooling airflow speed in Table 10 that will deliver
the nominal cooling airflow as listed in Table 1 for each
size.

fan speed

the interface

To change the gas heating speed:
1. Remove the vinyl cap off of the desired speed tap wire
(Refer to Table 6 for color coding). Table 10 shows the
temperature rise associated with each fan speed for a given
static pressure. Make sure that the speed chosen delivers a
temperature rise within the rise range listed on the unit
rating plate.

Two Cooling Fan
feature used)

of a 24 VAC dehumidistat

requires use of
which includes

control

= Med-High

Speed

Red = Med Speed
Pink = Med-Low Speed
Blue = Low Speed

Motor

Leads

speed

GAS
HEAT

HIGH

QC6

QC7

LOW

COM

000o
QC4

RL3

QC3
K1

R1L

Q1
O

t'T"

°00051;o °c0
JM6

OILL

RI2

-o
R2

in !
JW2

JW4

SSTZ-8

24VAC

i wl

Y2/ G
DH

Y!/

A09058

Fig. 14 - Interface
Table
FILTER

7 - Filter

Fan Board

Pressure

Drop

Table
CFM

SIZE

in. (mm)
20X20X1

(IFB)

1300

(IN.

W.C.)

1400

1600

600

700

600

900

1000

1100

1200

0.05

0.07

0.08

0.1

0.12

0.13

0.14

0.15

0.09

0.10

0.11

0.13

0.14

0.15

0.16

........

0.05

0.06

0.07

0.08

0.09

0.1

........

0.06

0.07

0.08

1700

1600

1900

2000

2100

2200

2300

0.09

0.10

0.11

0.12

0.13

0.14

...........

(508X508X25)
20X24X1

....

(506X610x25)
24X30X1

0.04

(610X762x25)
24X36X1

.......

0.09

(610X914X25)

Table
Unit

Size

500

24
30

600
0.06

700
0.07

800
0.08
0.12

900
0.09
0.15

8 - 48VT-A
1000
0.1
0.19
0.07

Wet

Coil

Pressure

Drop

Standard CFM (S.C.EM)
1100
1200
1300
1400

42
48

0.23
0.11

0.27
0.18
0.04

0.26
0.07

1500

0.35
0.1
0.11

0.15
0.14

Table
UNIT SIZE
36, 42
48
60

9 - Wet

Coil

Air

Delivery

0.1
1612
2298
2298

(CFM)
0.2
1569
2239
2239

- Downflow
0.3
1527
2180
2180

- High

Speed

EXTERNAL
0.4
1481
2110
2110

with

1-in.

(25 mm)

STATIC PRESSURE
0.5
0.6
1451
1393
2044
1951
2044
1951

1600

0.21
0.17
0.1

Filter

(in. W.C.)
0.7
1351
1862
1862

and

1700

1800

1900

2000

0.22
0.17

0.28
0.23

0.31

0.36

Economizer
0.8
1317
1777
1777

0.9
1278
1697
1697

1.0
1242
1591
1591

Table
Unit

10 - Dry Coil Air Delivery
Heating
Rise
Range

Motor

Wire

Speed

Color

CFM*

- Horizontal

Blue

0.1

0.2

754

650

Heating Rise
(oF)

Heating Rise

(oc)
CFM
MedPink
Low

Discharge

- Unit 48VT-A24-60

External Static Pressure

CFM
Low

and Downflow

Heating Rise
(OF)
Heating Rise

85_

0.3
_i

0.4

(in. W.C.)

0.5

0.6

0.7

0.8

0.9

_291

777

675

59_
51

774

684

(oc)
CFM
48VT(-,N)A24040

60°F

(17 -

33°C)

Medium 2

Red

94_'

85_

Heating Rise
(OF)

Heating Rise

(oc)
CFM
MedHigh1

Orange

Heating Rise
(OF)
Heating Rise

(oc)
CFM
High

Low

Black

Blue

Heating Rise
(OF)
Heating Rise
(oc)
C FM
Heating Rise
(OF)
Heating Rise

(oc)
MedLow

Pink

CFM
Heating Rise
(OF)
Heating Rise

(oc)
48VT(-,N)A24060

25 - 55°F

Medium 2

Red

(14 - 31°C)

CFM
Heating Rise
(OF)
Heating Rise

Orange

30
17

NA
NA

754

650

52
29
94_

29
667

_1_6_:

85_

25
759

12@_[

29
88_

NA
NA
675

NA
_[_,,,,

NA
73:_

NA
640

..........................................................................................................................
NA
31
34
37
41
47
NA

591
NA

774

684

NA
_6

759

667

Heating Rise
(OF)

Heating Rise

Heating Rise
(OF)

Heating Rise

CFM
Heating Rise
(oF)

973
31

887
34

823
37

t";--it
NA

Heating Rise

954

881

800

Heating Rise
(OF)

Heating Rise

996
30

915
33

840
36

CFM
Heating Rise
(OF)

'i86_
31

Heating Rise

CFM
Heating Rise
(OF)
Heating Rise

(oc)

840::

_29

_69

777

85_

(oc)
MedHigh

22
840

CFM
High 1

Black

(oc)

t ,,_=it,,'t ,,_=it,,'t ,,_=it,, t,,_=it,,'

CFM

Low

Blue

(oc)
MedLow 1

Pink

(oc)
CFM
48VT(-,N)A30040

60°F

(17 -

33°C)

Medium

Red

(oc)
MedHigh2

Orange

CFM
Heating Rise
(OF)
Heating Rise

(oc)
High

Black

(oc)

Table 10 - Dry Coil Air Delivery CFM* - Horizontal and Downflow Discharge - Unit 48VT-A24-60
Unit

Heating
Rise
Range

Motor

Wire

Speed

Color

External Static Pressure
0.1
CFM

Low

Blue

Heating Rise
(oF)

Pink
Low

74_

(in. W.C.)

0.3

0.4

0.5

0.6

0.7

0.8

0.9

;638

Heating Rise

CFM

973

887

823

(oc)
Med-

0.2

(Cont)

Heating Rise
(oF)
Heating Rise

NA
780

NA
[

665

_38,,,,,[

45_

(oc)
CFM
48VT(-,N)A30060

25 - 55°F
(14 - 31°C)

Medium

Red

Heating Rise
(OF)
Heating Rise

(oc)
CFM
MedHigh2

Orange

Black

Blue

Pink

48VT(-,N)A36060

Medium 2

Red

Black

Blue

48VT(-,N)A36090

Medium

Red

Black

Heating Rise
(OF)

Heating Rise

CFM
Heating Rise
(oF)

1176
38

1121
40

1079
41

1019
44

974
46

Heating Rise

CFM
Heating Rise
(oF)

1295
34

!_23_
36

1182
38

1126
39

1075
41

1016
44

Heating Rise

C FM
Heating Rise
(OF)

_$345
33

1194
37

1140
39

1095
41

1027
43

974
46

!92_
48

Heating Rise

Heating Rise
(OF)
Heating Rise
CFM
Heating Rise
(OF)

, !_28_::
35
19

!_23_
36
20

_150_

, !_452 :

_ _i"[

_323i

!_28:_::

1169

1130

[}_643
27

}_ 05
26

_4_3 :::

!_23_ !

Heating Rise

CFM
Heating Rise
(oF)

1176
58

1121
61

1079
63

1019
NA

974
NA

!:"75
NA

Heating Rise

1182

1126

1075

1016

Heating Rise
(oF)

Heating Rise

CFM
Heating Rise
(oF)

}_34_
51

1194
57

1140
60

1095
62

1027
NA

974
NA

Heating Rise

1169

1130

_282
53

_28_
55

Heating Rise
(OF)
Heating Rise
CFM
Heating Rise
(OF)
Heating Rise

(oc)

_23

_282

,}_28

480,,

(oc)
High

NA
56_

CFM
Orange

NA
[687

(oc)
MedHigh1

NA
_[[,

(oc)
35 - 65°F
(19 - 36°C)

NA
840

_6_

CFM
Pink

28
915

658",,, [563

(oc)
MedLow

26
996

[

(oc)
Low

(oc)
High

23
_1_40},

_23

CFM
Orange

(oc)
MedHigh

800

(oc)
25 - 55°F
(14 - 31°C)

881

(oc)
MedLow 1

954

(OF)
Heating Rise

(oc)
Low

_Q23i

Heating Rise

(oc)
High 1

1,O88['[

Table 10 - Dry Coil Air Delivery CFM* - Horizontal and Downflow Discharge - Unit 48VT-A24-60
Unit

Heating
Rise
Range

Motor

Wire

Speed

Color

Low 1

Blue

External Static Pressure

C FM
Heating Rise
(OF)
Heating Rise

(oc)
C FM
MedPink
Low

Heating Rise
(oF)
Heating Rise

0.1

0.2

0.3

0.4

1295
34

1234
36

1182
38

1126
39

(Cont)

(in. W.C.)

0.5

0.6

0.7

0.8

0.9
85

1345

1282

1235

1194

1140

1323

1282

1234

1169

1130

!92_

(oc)
CFM
48VT(-,N)A42060

25 - 55°F
(14 - 31°C)

Medium

Red

Heating Rise
(OF)

High2

Orange

Black

Low

Blue

Pink

17
!_492::
30

(OF)
Heating Rise

Heating Rise
(°F)
Heating Rise
(oc)
CFM
Heating Rise
(OF)
Heating Rise
CFM
Heating Rise
(OF)
Heating Rise

(oc)
48VT(-,N)A42090

65°F

(19 -

36°C)

Medium 1

Red

CFM
Heating Rise
(OF)
Heating Rise

Orange

Black

Blue

48VT(-,N)A48090

65°F

(19 -

36°C)

Medium

Red

1231
36

1188
37

......................................................................................................................................................................................
26
27
28
28
29
30
31
32
33
14

1295

1234

1182

1126

17
NA

1282

1235

1194

1140

_74

NA
92_

1282

1234

1169

1130

_4_

1362

1313

1278

1231

1188

Heating Rise

CFM
Heating Rise
(OF)

_48_,
46

_448
47

_ O_
48

Heating Rise

CFM
Heating Rise
(OF)

1430
48

1374
49

1327
51

Heating Rise

CFM
Heating Rise
(OF)

_4_

1,02_

18
[ 857:

1,095

18
89_

1345

_15Q_ , _452;:

17
[ 958

1323

1445

1389

1341

1281

Heating Rise
(oF)

Heating Rise

CFM
Heating Rise
(OF)

1558
44

1513
45

1474
46

1438
47

1404
48

1349
50

Heating Rise

(oc)
35

20
1278
35

CFM
Pink

19
1313
34

1358

(oc)
MedLow 1

19
1362
33

(oc)
Low

18
_4_
31

(oc)
High

17
_4_
31

(oc)
MedHigh2

_1_45
29

(oc)
MedLow

, !_452:1358

CFM
Heating Rise

(oc)
High

Heating Rise

(oc)
Med-

_150_

(oc)

t_'28_

, _

_072

CFM
MedHigh

Orange

Heating Rise
(OF)
Heating Rise

(oc)
CFM
High

Black

21
_74

Heating Rise
(OF)

Heating Rise

(oc)

Table 10 - Dry Coil Air Delivery CFM* - Horizontal and Downflow Discharge - Unit 48VT-A24-60
Unit

Heating
Rise
Range

Motor

Wire

Speed

Color

External Static Pressure

CFM
Low

Blue

Heating Rise
(oF)
Heating Rise

(oc)
CFM
MedPink
Low

Heating Rise
(oF)
Heating Rise

0.1

0.2

0.3

0.4

1430

1374

1327

12_;

0.5
;1223

1445

1389

1341

1281

NA
NA

(Cont)

(in. W.C.)
0.6

_1_6
NA

0.7
_1_2_

0.8
1,O_

NA
NA

0.9
; 1,O_,6
NA

_1_89

i _1_9

1558

1513

1474

1438

1404

1349

i_785
49

1236

NA
1Q2_

(oc)
CFM
48VT(-,N)A48115

(17 -

60°F

Medium 2

Red

33°C)

Heating Rise
(OF)
Heating Rise

CFM
Heating Rise

_2_1
41

(OF)
Heating Rise

(oc)
MedHigh1

Orange

(oc)
High

Black

CFM
Heating Rise
(OF)
Heating Rise

(oc)
CFM
Low

Blue

Heating Rise
(oF)
Heating Rise

Low

31
_2Q13:::
43

2_g_i:
40

1430

1374

1327

1341

1281

CFM
Heating Rise
(OF)

Heating Rise

CFM
Heating Rise
(OF)

Heating Rise

Heating Rise
(OF)
Heating Rise

NA
NA

!2_40:,
41

!2Q_:::
42

!_68,
44

23
_1_6

1389

Heating Rise
(oF)
Heating Rise

_ 98_i:
44

CFM
Pink

30
_2Q65'
42

1445

(oc)
Med-

30
!2088,,,,
42

_1_2_

_1_89

i _1_9

1558
62

1513
64

1474
65

1438
NA

1404
NA

1349
NA

_74
51

1236

NA
1Q2_

(oc)
48VT(-,N)A48130

65°F

(19 -

36°C)

Medium 2

Red

(oc)
CFM
MedHigh1

Orange

Heating Rise
(OF)
Heating Rise

(oc)
High

Black

(oc)
Low 1

Blue

(oc)
CFM
MedLow

Pink

48VT(-,N)A60090

Medium

Red

_2Q13:::

_ 98_i:

i_785

1678

1635

1602

Heating Rise
(oF)

Heating Rise

CFM
Heating Rise
(OF)

1843
37

1794
38

1753
39

1711
40

1675
41

1628
42

Heating Rise

(oc)
35 - 65°F
(19 - 36°C)

_2Q65

(oc)

t_349

CFM
MedHigh

Orange

Heating Rise
(OF)
Heating Rise

(oc)
CFM
High

Black

21
_74

Heating Rise
(OF)

Heating Rise

(oc)

Table 10 - Dry Coil Air Delivery CFM* - Horizontal and Downflow Discharge - Unit 48VT-A24-60
Unit

Heating
Rise
Range

Motor

Wire

Speed

Color

External Static Pressure
0.1
CFM

Low

Blue

1445

Heating Rise
(OF)

Pink
Low

0.3

0.4

0.5

_389;;

_1_3_

;128_

;1236

(in. W.C.)
0.6

0.7

_1_89;; _1_9
NA

Heating Rise

CFM
Heating Rise
(oF)
Heating Rise

1678
52

1635
53

1602
54

!_ 880 t

1843

1794

48
27

(oc)
Mad-

0.2

(Cont)
0.8
1,0_
NA

0.9
1,02_
NA

!_40_
NA

_1_3_
NA

1753

1711

1675

1628

i_785
49

!_4 _ _ !_438,,,,,
59
60

(oc)
C FM
48VT(-,N)A60115

60°F

(17 -

33°C)

Medium 2

Red

Heating Rise
(OF)
Heating Rise

CFM
Heating Rise

_2_1
41

(oc)
MadHigh1

Orange

(OF)
Heating Rise

(oc)
CFM
High

Low

Black

Blue

(°F)
Heating Rise
(oc)
Heating Rise
CFM
Heating Rise
(OF)
Heating Rise

(oc)
MadLow

Pink

CFM
Heating Rise
(OF)
Heating Rise

(oc)
48VT(-,N)A60130

65°F

(19 -

36°C)

Medium 2

Red

CFM
Heating Rise
(OF)
Heating Rise

(oc)
MadHigh1

Orange

Black

26
_2Q65'
42
23

26
_2Q13:::
43
24

_ 98_i:
44

_2_61

!2409

20
1445

20
_$389

21
_1_3_

21
128_

22
:1236

2_g_i:
38

1678

1635

1602

45
25
!2_40 :,
41

!2Q_:: : !_68,
42

23
_1_89

23
_1_9

26
1,02_

_1558

_15_3

_4_

1794

1753

1711

1675

1628

_880:1843

NA
140_

Heating Rise

CFM
Heating Rise
(OF)

_74
51

Heating Rise

* Air delivery values are without air filter and are for dry coil (See 48VT-A
1 Factory-shipped
gas heating speed

_2e13:::
_98_::

NA
_1_3_9

_2_1

(oc)

_2e88:_2e_5

NA
:_4_

CFM
Heating Rise
(OF)

(oc)
High

25
!2088,,,,
42

_785

Wet Coil Pressure Drop table).

2 Factory-shipped
heat pump speed
NA - Not allowed for gas heating speed
Note: Deduct field-supplied
air filter pressure drop and wet coil pressure drop to obtain external static pressure available for ducting.
Shaded areas indicate speed/static combinations that are not permitted for dehumidification
speed.

qD
z
q@

Ld
CO
Ld
0
L

Ld
IX3

o
c
c
L_

I!lll

(D
0._

<1_

q2
Ld

Z
0
q_p
(/)

¢'-/
CXr--q

Ld
d_b

::_

0
ZIZ
CO

F-q..)
LJ
LU

Ld
qO
Z
dZ_

i!i,!iii
q

A09268

Fig. 15 - 208/230-1-60

Wiring

Diagram,

Unit 48VT-A

c/)

c_
O
L

C?
c_

z
z
O

<
A09412

Fig. 17 - Cooling

Charging

Table-Subcooling

MAINTENANCE
To ensure continuing high performance and to minimize the
possibility of premature equipment failure, periodic maintenance
must be performed on this equipment.
This combination
heating/cooling unit should be inspected at least once each year by
a qualified service person. To troubleshoot cooling or heating of
units, refer to Tables 10, 11 and 12.
NOTE:
Consult your local dealer about the availability of a
maintenance contract.

PERSONAL
Failure

INJURY

AND UNIT

to follow this warning

or death and unit component

DAMAGE

HAZARD

could result in personal

injury

damage.

The ability to properly
perform
maintenance
on this
equipment requires certain expertise, mechanical
skills, tools
and equipment.
If you do not possess these, do not attempt to
perform any maintenance
on this equipment,
other than those
procedures recommended
in the Owner's Manual.

5. Check and inspect heating section before each heating
season. Clean and adjust when necessary.
6. Check flue hood and remove any obstructions, if necessary.
Air Filter
IMPORTANT: Never operate the unit without a suitable air filter
in the return-air duct system. Always replace the filter with the
same dimensional size and type as originally installed. (See Table 1
for recommended filter sizes.)
Inspect air filter(s) at least once each month and replace
(throwaway-type) or clean (cleanable-type) at least twice during
each heating and cooling season or whenever the filter(s) becomes
clogged with dust and/or lint.
Indoor Blower and Motor
NOTE: All motors are prelubricated. Do not attempt to lubricate
these motors.
For longer life, operating economy, and continuing efficiency,
clean accumulated dirt and grease from the blower wheel and
motor annually.

ELECTRICALSHOCK
ELECTRICALSHOCK

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

HAZARD

Failure to follow these warnings could result in personal
iniury or death:
1. Turn off electrical power to the unit and install a lockout
tag before performing any maintenance or service on this
unit.
2. Use extreme caution when removing panels and parts.
3. Never place anything combustible either on or in contact
with the unit.
4. Should overheating occur or the gas supply fail to shut
off, turn off external main manual gas valve to the unit.
Then shut off electrical supply.

UNIT OPERATION
Failure to follow
operation.

HAZARD
this caution

may result in improper

HAZARD

Disconnect and tag electrical power to the unit before cleaning
the blower motor and wheel.
Cleaning the Blower Motor and Wheel
1. Remove and disassemble blower assembly as follows:
a. Remove blower access panel (see Fig. 19).
b. Disconnect 5 pin plug and 4 pin plug from indoor
blower motor. Remove capacitor if required.
c. On all units, remove blower assembly from unit.
Remove screws securing blower to blower partition and
slide assembly out. Be careful not to tear insulation in
blower compartment.
d. Ensure proper reassembly by marking blower wheel and
motor in relation to blower housing before disassembly.
e. Loosen setscrew(s) that secures wheel to motor shaft.
Remove screws that secure motor mount brackets to
housing, and slide motor and motor mount out of
housing.
2. Remove and clean blower wheel as follows:
a. Ensure proper reassembly by marking wheel orientation.

Errors made when reconnecting wires may cause improper
and dangerous
operation. Label all wires prior to
disconnecting when servicing.

b. Lift wheel from housing. When handling and/or
cleaning blower wheel, be sure not to disturb balance
weights (clips) on blower wheel vanes.
c. Remove caked-on dirt from wheel and housing with a
brush. Remove lint and/or dirt accumulations from
wheel and housing with vacuum cleaner, using soft
brush attachment. Remove grease and oil with mild
solvent.

The minimum maintenance requirements for this equipment are as
follows:
1. Inspect air filter(s) each month. Clean or replace when
necessary. Certain geographical locations may require more
frequent inspections.
2. Inspect indoor coil, outdoor coil, drain pan, and condensate
drain each cooling season for cleanliness. Clean when
necessary.
3. Inspect blower motor and wheel for cleanliness at the
beginning of each heating and cooling season. Clean when
necessary. For first heating and cooling season, inspect
blower wheel bi-monthly to determine proper cleaning
frequency.

d. Reassemble wheel into housing.
e. Reassemble motor into housing. Be sure setscrews are
tightened on motor shaft flats and not on round part of
shaft. Reinstall blower into unit. Reinstall capacitor.
f. Connect 5 pin plug and 4 pin plug to indoor blower
motor.
g. Reinstall blower access panel (see Fig. 19).
3. Restore electrical power to unit. Start unit and check for
proper blower rotation and motor speeds during heating and
cooling cycles.

4. Check electrical connections for tightness and controls for
proper operation each heating and cooling season. Service
when necessary. Ensure electrical wiring is not in contact
with refrigerant tubing or sharp metal edges.

Flue
Integrated
Gas Unit

(IGC)
Auto
fuses

Transformer
used

2. Remove the 11 screws holding the flue collector box cover
(See Fig. 18) to the heat exchanger assembly. Inspect the
heat exchangers.
3. Clean all surfaces, as required, using a wire brush.
Limit Switch

(IFB)

Draft
Motor

Fan Partition

Flue

Mounting
Bracket

Collector
Box

RoIIout
Indu
Blower
Housing

Burner
Rack

Mounting
Screw

Remove blower access panel (see Fig. 19). Limit switch is located
on the fan partition.

Switch

A09199

Fig. 18 - Blower

Housing

and Flue

Collector

box and upper areas of the heat

1. Remove the induced draft blower assembly according to
directions in the Induced Draft Blower Assembly section.

on 460

(Hidden)

Board

Gas Passageways

To inspect the flue collector
exchanger:

Box

Burner

Ignition

Unit is equipped with a direct spark ignition 100 percent lockout
system. Ignition module (IGC) is located in the control box (See
Fig. 18). Module contains a self-diagnostic
LED. During
servicing, refer to label diagram or Table 5 in these instructions for
LED interpretation.
If lockout occurs, unit may be reset by either momentarily
interrupting power supply to unit or by turning selector switch to
OFF position at the thermostat.
Main Burners
At the beginning of each heating season, inspect for deterioration
or blockage due to corrosion or other causes. Observe the main
burner flames and adjust, if necessary.
Removal of Gas Train
To remove the gas train for servicing:
1. Shut off main gas valve.
2. Shut off power to unit and install lockout tag.
3. Remove control access panel (See Fig. 19).
4. Disconnect gas piping at unit gas valve.

Control
Access
Panel

Blower
Access
Panel

Compressor
Access Panel

5. Remove fan partition mounting bracket (2 screws located
on the left side of control compartment on the fan partition
panel). Slide bracket forward, bottom first to remove. (See
Fig. 18).
6. Remove wires connected to gas valve. Mark each wire.
7. Remove ignitor and sensor wires at the ignitor module.

A09214

Fig. 19 - Unit Access

Induced

Draft

The induced-draft
the blower housing,

(combustion

Panels

air) Blower

blower assembly consists of the inducer motor,
and the induced-draft blower wheel.

Clean periodically to assure proper airflow and heating efficiency.
Inspect blower wheel every fall and periodically during the heating
season. For the first heating season, inspect blower wheel
bimonthly to determine proper cleaning frequency.
To inspect
blower
wheel, remove draft hood assembly.
Shine a
flashlight into opening to inspect wheel. If cleaning is required,
remove induced-draft blower assembly
as follows:
1. Remove control access panel (See Fig. 19).
2. Remove the 5 screws that attach induced-draft
sembly to the flue collector box cover.

blower as-

3. Slide the assembly out of the unit. (See Fig. 20). Clean the
blower wheel. If additional cleaning is required, continue
with Steps 4 and 5.
4. To remove blower wheel, remove 2 setscrews.
5. To remove inducer motor,
remove
screws that hold
inducer motor to the blower housing.
6. To

reinstall,

8. Remove the mounting screw that attaches the burner rack to
the unit base (See Fig. 18).

Assembly

reverse

the procedure

outlined above.

the

9. Slide the burner rack out of the unit (See Fig. 18 and 21).
10. To reinstall, reverse the procedure outlined above.
Outdoor

Coil, Indoor

Coil, and Condensate

Drain

Pan

Inspect the outdoor coil, indoor coil, and condensate drain pan at
least once each year. The coils are easily cleaned when dry;
therefore, inspect and clean the coils either before or after each
cooling season. Remove all obstructions, including weeds and
shrubs, that interfere with the airflow through the condenser coil.
Straighten bent fins with a fin comb. If coated with dirt or lint,
clean the coils with a vacuum cleaner, using the soft brush
attachment. Be careful not to bend the fins. If coated with oil or
grease, clean the coils with a mild detergent-and-water
solution.
Rinse coils with clear water, using a garden hose. Be careful not to
splash water on motors, insulation, wiring, or air filter(s). For best
results, spray outdoor coil fins from inside to outside the unit. On
units with an outer and inner condenser coil, be sure to clean
between the coils. Be sure to flush all dirt and debris from the unit
base.
Inspect the drain pan and condensate drain line when inspecting
the coils. Clean the drain pan and condensate drain by removing all
foreign matter from the pan. Flush the pan and drain tube with
clear water. Do not splash water on the insulation, motor, wiring, or

airfilter(s).
If the

drain tube is restricted, clear it with a "plumbers
snake" or similar probe device. Ensure that the auxiliary drain port
above the drain tube is also clear.

Outdoor Fan

UNIT
Failure

BLOWER
HOUSING

OPERATION
to follow

HAZARD

this caution

may result in damage

to unit

components.
Keep the outdoor fan free from all obstructions
to ensure
proper cooling operation.
Never place articles on top of the
unit.
1. Remove
cover.

6 screws

holding

outdoor

grille

upside

down

2. Turn motor/grille
assembly
expose the fan blade.
2 SETSCREWS

3. Inspect

(HIDDEN)

the fan blades

5. When replacing fan blade,
position as before.

position

C99085

and

Blower

Electrical

engages

to top

cover

or bends.

loosen the setscrew

7. Replace
of Motor

on top

4. If fan needs to be removed,
fan off the motor shaft.

6. Ensure that setscrew
when tightening.

Fig. 20 - Removal

for cracks

and motor

and slide the

blade back to the same

the flat area on the motor

shaft

grille.

Controls

Wiring

and

Wheel
Inspect and check the electrical controls and wiring
sure to turn off the gas supply, and then the electrical
unit.
Remove

access

panels

(see Fig.

19) to locate

annually. Be
power to the

all the electrical

controls and wiring. Check all electrical connections
for tightness.
Tighten
all screw
connections.
If any discolored
or burned
connections
are noticed, disassemble
the connection,
clean all the
parts, re-strip
and securely.
After

the wire end and reassemble

inspecting

the

electrical

controls

the connection
and wiring,

properly
replace

the

access panels (see Fig. 19). Start the unit, and observe at least one
complete heating cycle and one complete cooling cycle to ensure
proper operation.
If discrepancies
are observed
in any operating
cycle, or if a suspected
malfunction
has occurred,
check each
electrical
component
with the proper electrical instrumentation.
Refer to the unit wiring label when making these checkouts.
A07680

Fig. 21 - Burner

Rack

Removed

NOTE:

Refer to the heating

and/or

publication

aid

this

cooling

sequence

determining

of operation

proper

control

operation.
FEEDERTUBE

Refrigerant

Circuit

Annually
inspect all refrigerant
tubing
base for oil accumulations.
Detecting

STUB TUBE

refrigerant

leak.

EXPLOSION,
PERSONAL
ENVIRONMENTAL
HAZARD
Failure to follow this warning
death or property damage.

DEFROST
THERMOSTAT

System under pressure.
refrigerant before system

C99029

Fig. 22 - Defrost

Thermostat

Location

service ports and open
solenoid valves.
If oil

connections
and the unit
oil generally
indicates
a

is detected

INJURY

AND

could result in personal

injury,

Relieve pressure
and recover all
repair or final unit disposal. Use all
all flow-control

or if low

cooling

devices,

performance

including

is suspected,

leak-test
all refrigerant
tubing using an electronic
leak-detector,
halide
torch, or liquid-soap
solution.
If a refrigerant
leak is
detected, refer to the Check for Refrigerant Leaks section.

If norefrigerant
leaks
arefoundandlowcooling
performance
is
suspected,
refertotheChecking
andAdjusting
Refrigerant
Charge
section.
Input

Gas

The gas input does not require checking unless improper heating
performance
is suspected. If a problem exists, refer to the Start-Up
section.
Indoor
The

Airflow

heating

and/or

cooling

airflow

does

unless improper performance
is suspected.
sure that all supplyand return-air
grilles

not

require

checking

If a problem exists, be
are open and free from

obstructions,
and that the air filter is clean. When necessary, refer to
the Indoor Airflow and Airflow Adjustments
section to check the
system

NOTE:

pressure,

troubleshooting

unless

If switch

must be removed,

so that

pressure

without

breaking

High-Pressure

Device

Expansion

Valve

This unit uses both a hard shutoff, balance port TXV in the indoor
coil and a piston in each side of the outdoor coil. The TXV
maintains a constant superheat at the evaporator coil exit (cooling
mode) resulting in higher overall system efficiency.
Pressure Switches
Pressure

switches

are protective

devices

wired

into

control

are specifically
R-22 pressure

for the Puron
Loss

designed
switches

(R-410A)

Charge

Copeland
The

2. Disconnect

leads on switch.

ohm

continuity

to unit.

meter

on a good

leads

across

switch.

You should

have

system

meter

leads

on a good

used
Puron

across

switch.

You

should

have

switch.
(Puron

Refrigerant)

in this product
(R-410A)

is specifically

refrigerant

and

designed

cannot

is an electrical (as well as mechanical)
caution when working near compressors.

should be shut off, if possible, for most troubleshooting
Refrigerants
present additional safety hazards.

EXPLOSION

fan

to unit.

Scroll Compressor

compressor

The compressor
Exercise extreme

device.
Power

techniques.

HAZARD

Failure to follow this warning could result in personal
or death and/or property damage.
Wear safety glasses and gloves when handling
Keep
torches
and other
ignition
sources
refrigerants
and oils.

Switch

1. Turn off all power

all system

open

leads on switch.

ohm

operate
with
interchanged.

system.

airflow across indoor coil, dirty filters, etc. It opens on a pressure
drop at about 20 psig. If system pressure
is above this, switch
should be closed. To check switch:

Never

Switch

continuity

to operate with Puron (R-410A)
must not be used as replacements

low
low

and recover

read 0 psi.

for

that a problem

with dry nitrogen.

1. Turn off all power

circuit

This switch is located on the liquid line and protects against
suction pressures caused by such events as loss of charge,

3. Apply

vacuum

this device

certain

remove

gauges

to refrigeration

to remove

High pressure may be caused by a dirty outdoor coil, failed
motor, or outdoor air recirculation.
To check switch:

(low voltage). They shut off compressor
if abnormally high or low
pressures
are present in the refrigeration
circuit. These pressure
switches
systems.

attached

The high-pressure
switch is located in the discharge
line and
protects against excessive condenser coil pressure. It opens at 650
psig.

3. Apply

(Thermostatic

are

you are reasonably

charge

Thermostat

The defrost thermostat is usually located on the lowest liquid
leaving circuit of the left condenser coil (see Fig. 22). The
thermostat closes at 32°F (0°C) and opens at 65°F (18°C).
Puron Items

switches

it is not advisable

exists.

2. Disconnect

Defrost

Metering
Piston)

these

under

airflow.

Check

Because

system

The scroll compressor

pumps

refrigerant

iniury

refrigerants.
away from

throughout

the system

the interaction
of a stationary
and an orbiting scroll. The scroll
compressor
has no dynamic suction or discharge valves, and it is
more tolerant of stresses caused by debris, liquid slugging,
and
flooded
pressure

starts. The
relief port.

compressor
The pressure

is equipped
relief port

with an internal
is a safety device,

designed to protect against extreme high pressure.
has an operating
range between
550 and 625
pressure.

The relief port
psi differential

o
-N
PO

"13

-_!:2:D-

Speedup
Pins

Quiet
Shift

Defrost interval
DIP switches
A08020

Fig. 23 - Defrost

Control

C99097

Fig. 24 - Refrigerant

OUTDOOR

Circuit

COIL
"__N

TXV

DOO R COIL

in Meterin
Position

I
r-q
LCS

Bypass
Position

LEGEND
HPS - High Pressure
LCS - Loss of Charge

Switch
Switch

Accurater_'Metering

[-_

Arrow indicates

Device

direction

of flow
C03011

Fig. 25 - Typical

Heat Pump

Operation,

Cooling

Mode

OUTDOOR

COIL

INDOOR COIL

TXV in Bypass
Position

:[:='1
LCS
1

J
Mete@g
Position

LEGEND
HPS - High Pressure Switch
LCS - Loss of Charge Switch
_

_i_ Accurate¢_Meteiing

[]

Device

Arrow indicates direction of flow
C03012

Fig. 26 - Typical

Heat

Pump

Operation,

Heating

Synthetic

Mode

Roof Precautionary

1. Cover

extended

polyethylene
UNIT

OPERATION

AND SAFETY

Failure to follow this warning
or equipment damage.
This system uses Puron
higher operating pressures
No other refrigerant may
hoses, and recovery system
If you are unsure, consult

HAZARD

approximate

could result in personal

containing
charging.
Compressor

synthetic

the refrigerant
system of the 48VT-A
oil needed, servicing systems on roofs

materials,

the

filter

drier

and

refrigerant

Oil

If additional oil is needed use Uniqema RL32-3MAF.
If this oil is
not available, use Copeland Ultra 32CC or Mobil Artic EAL22CC.
This oil is extremely
hygroscopic,
meaning
readily. POE oils can absorb 15 times as nmch

it absorbs
water
water as other oils

designed
for HCFC
and CFC refrigerants.
Take all necessary
precautions
to avoid exposure of the oil to the atmosphere.
Servicing

Systems

on Roofs and with Synthetic

POE (polyolester)
compressor
term damage to some synthetic

materials

lubricants are known
roofing materials.

Exposure,
even
if immediately
embrittlement
(leading to cracking)
When
performing
any service

to cause long

cleaned
up,
may
cause
to occur in one year or more.
that may
risk exposure
of

compressor
oil to the roof, take appropriate
precautions
to protect
roofing.
Procedures
which risk oil leakage include, but are not
limited to, compressor
replacement,
repairing
refrigerant
leaks,
replacing
refrigerant
components
such as filter drier, pressure
switch, metering

device,

coil, accumulator,

or reversing

valve.

(plastic)
10xl0

area

drip

with

cloth

an in, permeable
tarp.

Cover

panel with a terry
spills and prevent

drop cloth from tears caused by tools

3. Place terry cloth shop towel

inside

unit immediately

component(s)
to be serviced and prevent lubricant
through the louvered openings in the unit base.
required

Line Filter

under
run-offs

service.

5. Remove and dispose
local codes.
Liquid

fl (3x3 m) area.

run-offs,
and protect
or components.

(R-410A)
refrigerant
which has
than R-22 and other refrigerants.
be used in this system. Gauge set,
nmst be designed to handle Puron.
the equipment manufacturer.

System

This information
covers
including
the compressor

Procedure
working

2. Cover area in front of the unit service
cloth shop towel to absorb lubricant

iniury

4. Perform
Refrigerant

roof

of any oil contaminated

material

per

Drier

This filter drier is specifically

designed

to operate

with Puron. Use

only factory-authorized
components.
Filter drier must be replaced
whenever the refrigerant system is opened. When removing a filter
drier, use a tubing cutter to cut the drier from the system. Do not
unsweat a filter drier from the system. Heat from unsweating
release moisture and contaminants
from drier into system.
Puron

(R-410A)

Refrigerant

will

Charging

Refer to unit information
plate and charging chart. Some R-410A
refrigerant cylinders contain a dip tube to allow liquid refrigerant to
flow
with

from cylinder in upright position.
For cylinders
equipped
a dip tube, charge Puron units with cylinder
in upright

position
and a commercial
metering
Charge refrigerant into suction-line.

device

in manifold

hose.

TROUBLESHOOTING
Use the Troubleshooting
occur with these units,

Guides

(See Tables

10-12)

if problems

START-UP CHECKLIST
Use Start-Up
followed.

checklist

to ensure

proper

start-up

procedures

are

PURON®

•

(R-410A)

QUICK

REFERENCE

GUIDE

Puron refrigerant operates at 50-70 percent higher pressures than R-22. Be sure that servicing equipment and replacement
components are designed to operate with Puron

•

Puron refrigerant cylinders are rose colored.

•

Recovery cylinder service pressure rating must be 400 psig, DOT 4BA400 or DOT BW400.

•

Puron systems should be charged with liquid refrigerant. Use a commercial type metering device in the manifold hose when
charging into suction line with compressor operating
Manifold sets should be minimum 700 psig high side and 180 psig low side with 550 psig low-side retard.
Use hoses with minimum 700 psig service pressure rating.
Leak detectors should be designed to detect HFC refrigerant.
Puron, as with other HFCs, is only compatible with POE oils.
Vacuum pumps will not remove moisture from oil.
Do not use liquid-line filter driers with rated working pressures less than 600 psig.
Do not leave Puron suction line filter driers in line longer than 72 hrs.

Do not install a suction-line

filter drier in liquid line.

POE oils absorb moisture rapidly. Do not expose oil to atmosphere.
POE oils may cause damage to certain plastics and roofing materials.
Wrap all filter driers and service valves with wet cloth when brazing.
A factory approved liquid-line filter drier is required on every unit.
Do NOT use an R-22 TXV.
Never open system to atmosphere while it is under a vacuum.
When system must be opened for service, recover refrigerant, evacuate then break vacuum with dry nitrogen and replace filter

driers. Evacuate to 500 microns prior to recharging.
•

Do not vent Puron into the atmosphere.

•

Observe all warnings, cautions, and bold text.

•

All indoor coils must be installed with a hard shutoff Puron TXV metering device.

Table
11SYMPTOM

Compressor
start.

and Outdoor fan will not

Compressor
fan runs.

will not start but Outdoor

Troubleshooting

Scroll compressor

Compressor

Excessive

operates

head

continuously.

pressure.

Head pressure too low.

Excessive suction pressure.

pressure

too low.

power dead

runs but outdoor fan does

Mode

REMEDY
Call power company.
Replace fuse or reset circuit breaker.
Replace component.
Determine cause and correct.
Check wiring diagram and rewire correctly.
Lower thermostat setting below room temperature.
Check wiring and repair or replace.
Determine

cause Replace compressor.

Determine cause and replace.
Replace fuse or reset circuit breaker. Determine
cause.

is rotating in the wrong direction

overcharge

or undercharge

Correct

the

direction

power

Recover

of rotation

leads

refrigerant,

to capacities

to the
evacuate

shown

system,

cause.
correct.

cause

and

correct.

Determine

cause

and

replace.

Frosted coil with incorrect defrost operation

Check

defrost

essary
Clean

coil or remove

Indoor airflow

Temperature
too low in conditioned
area
Outdoor
ambient
below
55°F (12.8°C)
Field-installed
filter-drier
restricted

NC (normally

closed) contacts on defrost board open

the

and

recharge

on nameplate.

Determine

Outdoor coil dirty or restricted
Dirty air filter
Dirty Indoor or Outdoor coil
Refrigerant overcharged
Air in system
Indoor or Outdoor air restricted or air short-cycling
Low refrigerant charge
Compressor
IPR leaking
Restriction in liquid tube
High heat load
Compressor IPR leaking
Refrigerant overcharged
Reversing valve hung up or leaking internally
Dirty air filter
Low refrigerant charge
Metering device or low side restricted

by reversing
unit.

Replace
and determine
Determine
cause
and

(Heat) Outdoor coil frosted
Compressor
not

Heating

Defective compressor
Insufficient line voltage
Blocked Outdoor
Defective run/start capacitor, overload or start relay
Defective thermostat
Faulty Outdoor-fan
motor or capacitor
Damaged reversing valve
Restriction in refrigerant system
Dirty air filter
Unit undersized for load
Thermostat set too low
Low refrigerant charge
Mechanical damage in compressor.
Air in system

Insufficient
Suction

or Heat Pump

3-phase

Refrigerant

Compressor cycles (other than normally
satisfying thermostat).

- Cooling

CAUSE
Power Failure
Fuse blown or circuit breaker tripped
Defective thermostat, contactor, transformer, or control
relay
Insufficient line voltage
Incorrect or faulty wiring
Thermostat setting too high
Faulty wiring or loose connections in compressor circuit
Compressor motor burned out, seized, or internal overload open
Defective run/start capacitor, overload, start relay
One leg of 3-phase

Three-phase
scroll compressor makes
excessive noise, and there may
be a low pressure differential.

Guide

Replace
thermostat.
Replace.
Determine
cause
and correct
Locate
restriction
and remove.
Replace
filter.
Decrease
load or increase
Reset thermostat.
Locate

leak,

Replace

repair,

and

unit

size.

recharge.

compressor.

Recover
refrigerant,
Check
defrost
time

evacuate
system,
and recharge.
settings,
Reset as necessary

temperature

switch,

Replace

as nec-

restriction.

Replace
filter.
Clean
coil.
Recover

excess

refrigerant.

Recover
refrigerant,
evacuate
Determine
cause
and correct.
Check

for

leaks,

repair,

Replace
compressor.
Remove
restriction.
Check
for source
and
Replace

and

system,

excess

Replace
Replace

valve
Filter.

recharge.

eliminate.

refrigerant.

Check
for leaks, repair, and
Remove
source
of restriction.

recharge.

Increase

filter

Install

air quantity.

Check

replace

if neces-

thermostat.
low-ambient

Replace.
Move timer

kit.

on control

defrost

cycles

Check

condition

sary

recharge.

compressor.

Recover

sary.
Reset

and

board

of relay

to 30 minutes

on board

Replace

between

if neces-

Table
SYMPTOM

12 - Troubleshooting

Guide-Heating

CAUSE

REMEDY

Water in gas line
No power to furnace

Drain. Install drip leg.
Check power supply fuses, wiring or circuit breaker.
Check transformer.
NOTE: Some transformers have internal over-current
that requires a cool-down period to reset.

No 24-v power supply to control circuit
Burners

will not ignite

Inadequate

Mis-wired

heating

Poor flame characteristics

or loose connections

Check all wiring and wire nut connections

Misaligned spark electrodes

Check flame ignition and sense electrode
Adjust as necessary.

No gas at main burners

1. Check gas line for air. Purge as necessary. NOTE: After purging
gas line of air, wait at least 5 minutes for any gas to dissipate before attempting to light unit.
2. Check gas valve.

Dirty air filter

Clean or replace filter as necessary

Gas input to furnace too low

Check gas pressure at manifold match with that on unit nameplate

Unit undersized for application
Restricted airflow

Replace with proper unit or add additional unit
Clean or replace filter. Remove any restriction.

Limit switch cycles main burners

Check rotation of blower, temperature
sary.

Table

13 - Troubleshooting
CAUSE

positioning.

rise of unit. Adjust as neces-

1. Tighten all screws around burner compartment
2. Cracked heat exchanger. Replace.
3. Unit over-fired. Reduce input (change orifices or adjust gas line
or manifold pressure).
4. Check burner alignment.
5. Inspect heat exchanger for blockage. Clean as necessary.

Incomplete combustion results in: Aldehyde odors,
carbon monoxide, sooting flame, floating flame

SYMPTOM
No Power Hardware
(LED OFF)

protection

Guide-LED

Status

Codes
REMEDY

Check 5-amp fuse son IGC*, power to unit, 24-v circuit breaker,
and transformer. Units without a 24-v circuit breaker have an
internal overload in the 24-v transformer. If the overload trips,
allow 10 minutes for automatic reset.

failure
Loss of power to control module (IGC)*.

Limit switch faults
(LED 2 flashes)

High temperature

Flame sense fault
(LED 3 flashes)

The IGC* sensed flame that should not be present.

Reset unit. If problem persists, replace control board.

4 consecutive
limit switch
faults
(LED 4 flashes)

Inadequate airflow to unit.

Check the operation of the indoor (evaporator) fan motor and that
supply-air temperature rise agrees with range on unit nameplate
information.

Ignition lockout
(LED 5 flashes)

Check the operation of the indoor (evaporator) fan motor, Ensure
that the supply-air temperature rise is in accordance with the
range on the unit nameplate. Clean or replace filters.

limit switch is open.

Unit unsuccessfully

attempted

ignition for 15 minutes.

Check ignitor and flame sensor electrode spacing, gaps, etc.
Ensure that fame sense and ignition wires are properly terminated.
Verify that unit is obtaining proper amount of gas.
Verify wiring connections

Pressure Switch
(LED 6 flashes)

motor

fault
Open pressure

to pressure switch and inducer motor.

Verify pressure switch hose is tightly connected to both inducer
housing and pressure switch, Verify inducer wheel is properly
attached to inducer motor shaft. Verify inducer motor shaft is turning.

switch,

Rollout switch fault
(LED 7 flashes)

Rollout switch has opened,

Rollout switch will automatically reset, but IGC will continue to
lockout unit. Check gas valve operation. Ensure that induced-draft
blower wheel is properly secured to motor shaft. Inspect heat
exchanger. Reset unit at unit disconnect.

Internal control
(LED 8 flashes)

Microprocessor
or hardware.

If error code is not cleared by resetting unit power, replace the
IGC*.

fault

Temporary I hr auto reset
(LED 9 flashes)
*WARNING

has sensed an error in the software

Electrical interference

.!_ : If the IGC must be replaced,

Reset 24-v. to control board or turn thermostat off, then on again.
Fault will automatically reset itself in one (1) hour.

impeding IGC software

be sure to ground

yourself to dissipate

any electrical

board. The IGC is sensitive to static electricity and my be damaged if the necessary precautions
IMPORTANT: Refer to Table 12-Troubleshooting
Guide-Heating
for additional troubleshooting
LEGEND
IGC--Integrated
Gas Unit Controller
LED--Light-Emitting
Diode

charge that my be present before handling

are not taken.
analysis.

new control

START-UP
(Remove
I. PRELIMINARY
MODEL

NO.:

SERIAL

NO.:

CHECKLIST

and Store

in Job

Files)

INFORMATION

DATE:
TECHNICIAN:

II. PRESTART-UP
( ) VERIFY

(Insert

check mark in box as each item is completed)

THAT ALL PACKING

( ) REMOVE

ALL SHIPPING

MATERIALS

HOLD

DOWN

( ) CHECK

ALL ELECTRICAL

( ) CHECK

GAS

( ) CHECK

THAT

INDOOR

( ) VERIFY

THAT

UNIT INSTALLATION

( ) CHECK

FAN WHEEL,

PIPING

HAVE BEEN REMOVED

BOLTS AND BRACKETS

CONNECTIONS

FOR LEAKS

AND TERMINALS

(WHERE

(EVAPORATOR)

FROM

APPLICABLE)

AIR FILTER

IS CLEAN

AND

IN PLACE

IS LEVEL

AND PROPELLER

FOR LOCATION

IN HOUSING/ORIFICE

ELECTRICAL
VOLTAGE

COMPRESSOR
INDOOR

AMPS

(EVAPORATOR)

FAN AMPS

TEMPERATURES
OUTDOOR

(CONDENSER)

RETURN-AIR
COOLING

GAS HEAT

AIR TEMPERATURE

TEMPERATURE
SUPPLY

HEAT PUMP

AIR

SUPPLY
SUPPLY

AIR
AIR

PRESSURES
GAS INLET

PRESSURE

GAS MANIFOLD

SUCTION

REFRIGERANT

DISCHARGE

( ) VERIFY

REFRIGERANT

GAS HEAT

TEMPERATURE

TEMPERATURE
MEASURED
* Measured

IN. W.C.

PRESSURE

REFRIGERANT

IN. W.C.
PSIG,

at suction

USING

CHARGING

LINE

TEMP*

LIQUID

TEMPi-

CHARTS

RISE

RISE (See Literature)
TEMPERATURE

SUCTION
PSIG,

CHARGE

INSTRUCTIONS

FOR TIGHTNESS

III. START-UP

SUPPLY

UNIT

PER INSTALLATION

RANGE

RISE

inlet to compressor

1- Measured at liquid line leaving condenser.

AND

SETSCREW

TIGHTNESS

2009 Carrier Corp. • 7310 W. Morris

Manufacturer

reserves

the right to change,

St. • Indianapolis,

IN 46231

at any time, specification8

and design8

Edition Date:
without

08/09

notice and without

Catalog No: 48VT-06SI
obligations,

Replaces:

48VT-

05Sl

Source Exif Data:

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Create Date                     : Fri Feb 12 04:27:48 2010
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Title                           : 
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CARRIER Package Units(both Units Combined) Manual L1001389

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