Carrier 48TC series Guide

User's Information Manual
NOTE: Read the entire instruction manual before starting
the installation.
ELECTRICAL SHOCK, FIRE OR EXPLOSION
HAZARD
Failure to follow safety warnings exactly could result
in dangerous operation, serious injury, death or
property damage.
Improper servicing could result in dangerous
operation, serious injury, death or property damage.
• Before servicing, disconnect all electrical power to
the unit.
• When servicing controls, label all wires prior to
disconnecting. Reconnect wires correctly.
• Verify proper operation after servicing.
NOTE TO INSTALLER:
This manual should be left with the equipment owner.
TABLE OF CONTENTS
PAGE
SAFETY CONSIDERATIONS .................... 1
TO LIGHT UNIT .............................. 3
TO SHUT UNIT OFF ........................... 4
ROUTINE MAINTENANCE & (:ARE
FOR THE EQUIPMENT OWNER ................. 5
BEFORE YOU CALL FOR SERVICE ............. 7
REGULAR DEALER MAINTENANCE ............ 8
SAFETY CONSIDERATIONS
Improper installation, adjustment, alteration, service,
maintenance, or use can cause fire, electrical shock, or
other conditions which may cause personal injury or
property damage. Consult a qualified installer, service
agency or your distributor or branch for information or
assistance. The qualified installer or agency must use
factory-authorized kits or accessories when modifying
this product. Refer to the individual instructions packaged
with the kits or accessories when installing.
Follow all safety codes and wear safety glasses. Have fire
extinguisher available. Read these instructions thoroughly
and follow all warnings or cautions attached to the unit.
Consult local and state building codes and Sheet Metal
and Air Conditioning National Association (SMACNA)
for special installation requirements.
Recognize safety information. This is the safety-alert
symbol A'x. When you see this symbol on the unit or in
instructions and manuals, be alert to the potential for
personal injury. Understand the signal words DANGER,
WARNING, and CAUTION. These words are used with
the safety-alert symbol. DANGER identifies the most
serious hazards, which will result in severe personal injury
or death. WARNING signifies hazards, which could result
in personal injury or death. CAUTION is used to identify
unsafe practices, which may result in minor personal
injury or product and property damage. NOTE is used to
highlight suggestions which will result in enhanced
installation, reliability, or operation.
Should the gas supply fail to shut off or if overheating
occurs, shut off the gas valve to the furnace (see Fig. 15)
before shutting off the electrical supply
FIRE, EXPLOSION HAZARD
Failure to follow this warning could result in personal
injury or death.
What to do if you smell gas:
• Leave the building.
• Do not try to light any appliance.
• Do not touch any electrical switch; do not use any
phone in your building.
• Immediately call your gas supplier from a neighbor's
phone. Follow the gas supplier's instructions.
• If you cannot reach your gas supplier, call the fire
department.
Installation and service must be performed by a
qualified installer, service agency or the gas supplier.

FIRE, EXPLOSION HAZARD
Failure to follow this warning could result in personal
injury, death and/or property damage.
Do not store or use gasoline or other flammable
vapors and liquids in the vicinity of this or any other
appliance.
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury, death and/or property damage.
Before performing maintenance, be sure main power
switch to unit is turned off and lockout tag is installed.
There may be more than one power switch.
ELECTRICAL OPERATION HAZARD
Failure to follow this warning could result in personal
injury, death and/or property damage.
Do not use this equipment if any part has been under
water. A flood-damaged equipment is extremely
dangerous. Attempts to use the equipment can result
in fire or explosion. A qualified service agency should
be contacted to inspect the equipment and to replace
all gas controls, control system parts, electrical parts
that have been wet or the equipment if deemed
necessary.
Your rooftop heating/cooling unit is equipped with an
automatic, direct spark ignitor and an induced-draft,
combustion blower.
• DO Make sure:
1. All flue and vent connections are clear and free of
obstructions, are leak free, and not damaged.
2. Duct connections are leak free and physically sound.
3. The unit base support is free of cracks, gaps, etc.
4. There are no signs of furnace deterioration.
5. Burners are aligned correctly.
6. Follow routine maintenance inspection.
• DO NOT: Keep combustible materials, gasoline, and
other flammable liquids or vapors around your
equipment.
• DO NOT: Cover your equipment in any manner.
• DO NOT: Store anything (including trash or debris)
near your equipment.
• DO NOT: In any way block or restrict airflow around
your equipment.
• DO NOT: Contaminate the air used for combustion of
your equipment with any kind of chemical or fumes.
This could also cause heat exchangers, metal vent
systems or components to deteriorate.
FIRE, EXPLOSION HAZARD
Failure to follow this warning could result in personal
injury, death and/or property damage.
1. Do not turn off the electrical power to unit
without first turning off the gas supply.
2. Before attempting to start the gas heating section,
familiarize yourself with all the procedures that
must be followed.
3. Never attempt to manually light the burners on
the unit with a match, lighter, or any other flame.
If the electric sparking device fails to light the
burners, refer to the shutdown procedures, then
call your dealer as soon as possible.
PERSONAL INJURY HAZARD
Failure to follow this warning could result in personal
injury.
Burners will light automatically. Do not attempt to
light by hand.
IMPORTANT FACTS
• DO: READ AND UNDERSTAND THIS MANUAL.
• DO: Have your equipment and vent system inspected
annually by a qualified service technician.
• DO: Inspect your filter monthly and clean or replace
when needed.
• DO: Provide adequate airflow to the equipment for
efficient combustion and safe ventilation.
CUT HAZARD
Failure to follow this caution may result in personal
injury.
When removing access panels or performing
maintenance functions inside your unit, be aware of
sharp sheet metal parts and screws. Although special
care has been taken to reduce sharp edges inside the
unit, be extremely careful when handling parts or
reaching into the unit.

TO LIGHT UNIT
Step 11 Set room thermostat/unit controller to the
lowest temperature setting and set the SYSTEM
switch to HEAT or AUTO position. See Fig. 1.
Fig. 1 - Thermostat/Unit Controller C07381
Step 2 1 Turn off the gas supply by closing the gas
supply shut-off valve (external to RTU unit). See Fig.
2 or 3 (depending on the size of the unit) for location.
Gas Supply Shut Off Valve
Jpplied)
[MA,Ni[
....oF,¢_?_,
C07831
Fig. 5-RTU Main Disconnect - Electrical Supply
Step 4 1 Remove the gas component access panel.
For location of the gas component access panel, see
Fig. 6 or Fig. 7 (depending on the size of the unit).
GASCOMPONENT
ACCESS PANEL
®
C07358
Fig. 2 - Gas Supply Shut-Off Valve Location
3 to 121/2 Ton Units
(Thru the base gas supply shown.)
RTU GAS VALVE
Fig. 6 - Gas Component Access Panel
and RTU Gas Valve Location
C08397
Gas Supply Shut OffValve
(Field Supplied)
C08485
Fig. 3 - Gas Supply Shut-Off Valve Location
15 to 28 Ton Units
Fig. 4 - Gas Supply Shut Off Valve C07330
Step 31 Turn off the electrical supply to the unit by
switching the RTU main disconnect to OFF. Then,
ensure personal safety by installing a lockout tag on
the disconnect.
)NENT
ACCESS PANEL
PANEL
C08486
Fig. 7- Gas Component Access and Filter Access
Panels - 15 to 28 Ton Units
C08487
Fig. 8-Gas Component Access Panel Removal
Step 51 Move the RTU gas valve on/off switch to the
OFF position and wait 5 minutes. See Fig. 6 or Fig. 7,
depending on the type of unit, for location of RTU gas
valve.

Single-Stage
RTUgas valve
_. On/Off
_'--Switch
Two-Stage 300k BTU/Hr
RTU gas valve Two-Stage
4-- sCni/tOff
C08469
Fig. 9 - Single- and Two-Stage RTU Gas Valves
Step 6 1 Move the RTU gas valve on/off switch to
the ON position.
Step 7 1 Replace the gas component access panel.
C08490
Fig. 10 - Replacing the Gas Component Access Panel
Step 8 1 Remove disconnect lockout tag and restore
power to the unit by switching the RTU main
disconnect to ON.
C07336
Fig. 11 - RTU Main Disconnect - Electrical Supply
Step 9 1 Turn on the gas supply by opening the gas
supply shut-off valve.
Fig. 12 - Gas Supply Shut Off Valve C07337
Fig. 13 - Thermostat/Unit Controller C07381
FIRE, EXPLOSION HAZARD
Failure to follow this warning could result in personal
injury, death or property damage.
If the main burners fail to light, or the blower fails to
come on, shut down gas heating section and call your
dealer for service.
TO SHUT UNIT OFF
FIRE, EXPLOSION HAZARD
Failure to follow this warning could result in personal
injury, death and/or property damage.
1. Turn off gas supply by closing the gas line supply
valve. Then, turn off the electrical power supply to the
unit by switching the diseonnect to off: Install lockout
tag before servicing or performing maintenance.
2. Do not turn off the electrical power to unit
without first turning off the gas supply.
Should overheating occur, or the gas supply fail to shut
oft'. shut off the gas valve in the unit (by moving on/off
switch to off) before shutting off the electrical supply.
Step 11 Set room thermostat/unit controller heat
setpoint to the lowest temperature setting and set the
SYSTEM switch to OFF.
Step 10 1 To start unit, set room thermostat/unit
controller heat setpoint to slightly above room
temperature. The induced-draft combustion air fan will
start. The RTU gas valve will open and main burners
should ignite within 5 seconds. If the burners do not
light, there is a 22-second delay. Burners will attempt
to ignite within 5-seconds. Each time the burner fails to
light, the 22-second time delay is repeated. If the
burner does not light within 15 minutes, the unit will
lockout the gas heat. To reset after a lockout, turn off
the main electrical supply to the unit by switching the
RTU main disconnect to OFF for a minimum of five
seconds. Repeat Steps 1-10. If burners still do not light,
call for service.
Step 11 1 Set the room thermostat/unit controller
heating setpoint to desired temperature setting.
C07381
Fig. 14 - Thermostat/Unit Controller
Step 2 1 Turn off gas supply by closing the gas
supply shut-off valve (external to RTU unit). See Fig.
3 or Fig. 4 (depending on the size of the unit) for
location.
Fig. 15 - Gas Supply Shut Off Valve C07330

Step 3 1 Turn off the electrical supply to the unit by
switching the RTU main disconnect to off. Then,
ensure personal safety by installing a lockout tag on
the disconnect.
C07331
Fig. 16 - RTU Main Disconnect - Electrical Supply
Step 41 Remove the gas component access panel.
For location of the gas component access panel, see
Fig. 6 or Fig. 7 (depending on the size of the unit).
C08487
Fig. 17 - Gas Component Access Panel Removal
Step 5 1 Move the RTU gas valve on/off switch to
the OFF position and wait 5 minutes.
Single-Stage
RTU gas valve
_. On/Off
_--Switch
Two-Stage 300k BTU/Hr
RTU gas valve Two-Stage
RTU gas valve
On/Off Ht • I-I[ _=_--J"l
_r--Switch II II
C08469
Fig. 18 -Single- and Two-Stage Gas Valves
Step 61 Replace the gas component access panel.
C08490
Fig. 19 - Replacing the Gas Component Access Panel
Step 7 1 If the unit is being shut down because of a
malfunction, contact your dealer as soon as possible.
DO NOT proceed to step 8.
Step 8 1 If the unit is being shut down because the
heating season has ended, remove the disconnect
lockout tag and restore electrical power to the unit by
switching the RTU main disconnect to ON and then set
thermostat/unit controller to the COOL position to
ensure operation of the cooling system during the
cooling season.
MAIN _.__[["-]
C07336
Fig. 20 - RTU Main Disconnect - Electrical Supply
ROUTINE MAINTENANCE & CARE
FOR THE EQUIPMENT OWNER
While some maintenance can be performed by laymen,
most should be performed by skilled, experienced
personnel. Follow the recommended service maintenance
schedule, and modify it as necessary for your
application/environment. For instance, dusty areas may
require more frequent filter changes.
After performing any maintenance or service on the unit,
be sure all panels are securely fastened in place to prevent
rain from entering unit cabinet and to prevent disruption
of the correct unit airflow pattern.
FIRE AND EQUIPMENT DAMAGE HAZARD
Failure to follow this warning could result in personal
injury and damage to equipment.
Do not use this unit if any part has been under water.
Immediately call a qualified service technician to
inspect the unit and to replace any part of the control
system and gas control that has been under water.
To ensure proper functioning of the unit, flow of
combustion and ventilating air must not be obstructed
from reaching the unit. Follow service and performance
clearances as listed in the product data.
Consider the following information before maintaining or
servicing equipment:
Compressor
All compressors are factory supplied with a normal charge
of the correct type refrigeration-grade oil in them and
should not require additional oil.
Indoor Air Filter(s)
FIRE AND EQUIPMENT DAMAGE HAZARD
Failure to follow this warning could result in personal
injury and damage to equipment.
Never operate unit without filters in place. The
accumulation of dirt, dust or lint on the internal parts
of your unit can cause fire or a loss of efficiency.
Damage to the blower motor and/or compressors
could also result.

Indoor air filter(s) should be checked every 3 or 4 weeks
(application dependant) and changed or cleaned when
necessary. See Fig. 21 or Fig. 22 (depending on the size of
the unit) for air filter access panel location. See Tables 1
and 2 for replacement filter dimensions.
• Lift up and remove air filter access panel (3 to 121/2 ton
units) or remove the screws securing the filter access
panel (15 to 25 ton units).
• While holding filters, tilt upper filter rack.
• Remove filters by pulling up and out toward you from
the track.
• Inspect filters. Clean or replace as necessary.
• Follow direction of airflow arrows as noted on filter
frame when returning filters to rack.
• Reinstall air filter access panel.
If you have difficulty in locating your air filter or if you
have questions concerning proper filter maintenance,
contact your dealer for instructions. When replacing your
unit filters, always use the same size and type of filter that
was originally supplied by the installer.
AIR FILTER ACCESS PANEL
Table 1-Replacement Filters - Size and Quantity
Size Capacity
04 3 tons
05 4 tons
06 5 tons
07 6 tons
08 7.5 tons
09 8.5 tons
12 10 tons
14 12.5 tons
16 15 tons
17 15 tons
20 17.5 tons
24 20 tons
28 25 tons
30 27.5 tons
48TC/580J
16 x 25 (2)
16 x 16 (4)
16 x 20 (4)
20 x 20 (4)
18 x 24 (6)
20 x 25 (6)
16 x 25 (9)
48HC/581J
16 x 25 (2)
16 x 16 (4)
16 x 20 (4)
20 x 20 (4)
18 x 24 (6)
20 x 25 (6)
16 x 25 (9)
NOTE: Filter sizes in Table 1 are in inches. Numbers in ( )
denote filter quantity. See Table 2 (on page 8) for additional
unit listings.
Units with outdoor air capability have a cleanable filter
for the outdoor air. This filter should be checked
semi-annually and cleaned as necessary with steam or hot
water and a mild detergent. Do not use throwaway filters
in place of cleanable filters.
Condenser Fan
C07359
Fig. 21 -Air Filter Access Panel -- 3 to 121/2 ton units
PERSONAL INJURY HAZARD
Failure to follow this warning could result in personal
injury.
Do not poke sticks, screwdrivers, or other object into
revolving fan blades.
NENT
ACCESS PANEL
"FILTERACCESS
PANEL
CO8486
Fig. 22 - Air Filter Access Panel -- 15 to 25 Ton Units
Electrical Controls and Wiring
Ensure wires do not contact refrigerant tubing or sharp
edges. Electrical controls are difficult to check without
proper instrumentation. If inadequate cooling is suspected,
contact your qualified local dealer for service.
Combustion Area and Vent System
The combustion area and vent system should be visually
inspected before each heating season.
FIRE HAZARD
Failure to follow this warning could result in personal
injury equipment damage.
If your unit makes any unusual or especially loud
noises during heating, shut down the heating section
and call your qualified service technician.

Proceedasfollowsto inspectthecombustionareaand
power-ventingsystemofyourunit.
•Turn off gas supply to your unit.
• Turn off electrical power to your unit; install lockout tag.
• Remove gas component access panel.
• Using a flashlight, carefully inspect the burner areas for
dirt, soot, or scale.
EQUIPMENT DAMAGE HAZARD
Failure to follow this caution may result in damage to
equipment.
If dirt, soot, rust or scale accumulations are found, call
your service technician and do not operate your
heating section.
• When you have completed your inspection, follow the
start-up procedures in this manual to restore your unit
to operation.
PERSONAL INJURY HAZARD
Failure to follow this warning could result in personal
injury.
Components in heat section may be hot after unit has
been started up. When observing flame, be careful not
to get close to or touch heating components.
•Observe unit heating operation. Watch the burner flame
to see if it is bright blue. If you observe a suspected
malfunction or that the burner flame is not bright blue,
shut down the unit and call your dealer.
• Replace gas component access panel.
Integrated Gas Controller (IGC)
The IGC board incorporates an LED that emits a flashing
light to indicate an alarm code. If the furnace section will
not operate and the LED is flashing a code (1 to 9 flashes
in succession), contact your dealer and request service.
NOTE: Make note of the flash code before powering off
the unit. The alarm codes clear after power cycle.
Unit Panels
After performing any maintenance or service on the unit,
be sure all panels are securely fastened in place to prevent
rain from entering unit cabinet and to prevent disruption
of the correct unit airflow pattern.
BEFORE YOU CALL FOR SERVICE,
CHECK FOR PROBLEMS THAT
CAN BE EASILY SOLVED
If insufficient heating or cooling is suspected:
( ) Check for sufficient airflow. Check the air filter for dirt
Check for blocked return- or supply-air grilles. Be sure
they are open and unobstructed. If these checks do not
reveal the cause, call your servicing dealer.
If your unit is not operating at all, check the following list
for easy solutions:
( ) Check to be sure that your thermostat/unit controller
temperature selector is set above the indoor temperature
during the heating season, or below the indoor
temperature during the cooling season. Be sure the
SYSTEM switch in the proper HEAT or COOL position
and not in the OFF position.
( ) Is the electrical supply switch ON'? Are any fuses
blown, or has the circuit breaker tripped'?
( ) During the heating season, check the external manual
shutoff valve. Is this lever parallel with the pipe,
indicating that the valve is open'? Or is the lever at the
right angle, indicating that the valve is closed'? If closed,
has the gas been shut off for safety reasons'? Otherwise,
you may open the valve and follow the start-up
procedures listed in this manual.
NOTE: Before proceeding with the next check, turn OFF
the electrical power supply to the unit. Remove the gas
component access panel.
( ) During the heating season, check the control switch on
the gas valve. Is it in the ON position'? If it is not, be sure
it has not been turned off for the purpose of safety. If no
safety hazards are present, follow the start-up procedures
in this manual.
( ) If your unit still fails to operate, call your servicing
dealer for troubleshooting and repairs. Specify the model
and serial numbers of your unit. (Record them in this
manual in the space provided.) If the dealer knows exactly
which unit you have, he may be able to offer suggestions
over the phone, or save valuable time through
knowledgeable preparation for the service call.
IN CASE OF TROUBLE
If, after performing the above checks, unit performance is
unsatisfactory, shut off the unit and call your dealer.
Dealer's Name
Telephone No.
Unit Model
Unit Serial Number

REGULAR DEALER MAINTENANCE
Heat Exchanger
NOTE: To ensure dependable and efficient heating
operation, the heat exchanger should be checked by a
qualified maintenance person before each heating season,
and cleaned when necessary.
EQUIPMENT DAMAGE HAZARD
Failure to follow this caution may result in damage to
equipment.
This checkout should not be attempted by anyone not
having the required expertise and equipment to do the
job properly.
Checking and/or cleaning the heat exchanger involves
removing the gas controls assembly and the flue collector
box cover. When finished, the gas controls must be
reinstalled for proper operation. Also, the flue collector
box cover must be replaced correctly, with "red" RTM so
that a proper seal is maintained. Contact your dealer for
the required periodic maintenance. At the beginning of
each cooling/heating season and as conditions require.
Fans and Belts, and Fan Motor
Check quarterly the condition of fan wheels and housings,
belt tension and fan motor shaft bearings. No lubrication
of condenser or evaporator fan bearings or motors is
required or recommended.
• Inspection and if required, cleaning of the condenser
and evaporator coils.
• Inspection, and if required, cleaning of the condensate
drain pan.
• Inspection and cleaning of blower wheel housing and
motor.
• Inspection of all supply- and return-air ducts for leaks,
obstructions, and insulation integrity. Any problems
found should be resolved at the time of inspection.
• Inspection of the unit base for cracks, gaps, etc., which
may cause a hazardous condition.
• Inspection of the unit casing for signs of deterioration.
• Inspection of all electrical wiring and components to
ensure proper connection.
• Inspection for leaks in the refrigerant circuit. Pressure
check to determine appropriate refrigerant charge.
• Inspection of fan wheels and housings, belt tension, and
fan motor shaft bearings.
• Operational check of the unit to determine working
conditions. Repair or adjustment should be made at the
time of inspection.
Your servicing dealer may offer an economical service
contract that covers seasonal inspections. Ask for
further details.
Complete service instructions can be found in the unit
Installation, Start-Up and Service Instructions.
Evaporator and Condenser Coils
Cleaning of the coils should be done by qualified service
personnel. This procedure should be performed prior to
cooling operation or more frequently should conditions
require. Contact you dealer for the required annual
maintenance.
Condensate Drain
The drain pan and condensate drain line should be
checked and cleaned at the same time the cooling coils are
checked by your dealer.
In addition to the type of routine maintenance you might be
willing to perform, your unit should be inspected regularly
by a properly trained and qualified service technician. An
inspection (preferably each heating/cooling season, but at
least every year) should include the following:
• Inspection of all flue product passages, including the
burners, heat exchanger, and flue collector box.
• Inspection of all combustion- and ventilation-air
passages and openings.
• Close inspection of all gas pipes leading to and inside
your unit.
Table 2-Replacement Filters -Size and Quantity (cont)
Capacity
3 tons
4 tons
5 tons
6 tons
7.5 tons
8.5 tons
10 tons
12.5 tons
15 tons
15 tons
17.5 tons
20 tons
25 tons
RGS Series
16 x 25 (2)
16 x 16 (4)
16 x 20 (4)
20 x 20 (4)
18 x 24 (6)
20 x 25 (6)
16 x 25 (9)
RGH Series
16 x 25 (2)
16 x 16 (4)
16 x 20 (4)
20 x 20 (4)
18 x 24 (6)
20 x 25 (6)
16 x 25 (9)
NOTE: Filter sizes in Table 2 are in inches. Numbers in
( ) denote filter quantity.
Copyright 2011 CAC /BDP •7310 W. Morris St. • Indianapolis, IN 46231 Printed in U.S.A. Edition Date: 07/11
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations,
Catalog No: OG-48TC580J-05
Replaces: OG- 48TC580J- 04