Carrier PACKAGE ROOFTOP 48HC Guide

48HC with EnergyXRSystem
Factory Installed Energy Recovery
Single---Package Rooftop Unit (RTU)
Gas Heating/Electric Cooling Units
15 to 25 Nominal Tons
with Puronr(R ---410A) Refrigerant
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.
SBefore servicing, disconnect all electrical power to
the unit.
SWhen servicing controls, label all wires prior to
disconnecting. Reconnect wires correctly.
SVerify proper operation after servicing.
!WARNING
NOTE TO INSTALLER:
This manual should be left with the equipment owner.
TABLE OF CONTENTS Page
SAFETY CONSIDERATIONS 1....................
COMFORTLINK CONTROL 3
TO LIGHT UNIT 3..............................
TO SHUT OFF UNIT 4...........................
ROUTINE MAINTENANCE & CARE
FOR THE EQUIPMENT OWNER 6.................
REGULAR DEALER MAINTENANCE 9............
BEFORE YOU CALL FOR SERVICE 10............
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 . 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,andCAUTION. 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 Figs. 2
and 3) before shutting off the electrical supply.

2
FIRE, EXPLOSION HAZARD
Failure to follow this warning could result in personal
injury or death.
What to do if you smell gas:
SLeave the building.
SDo not try to light any appliance.
SDo not touch any electrical switch; do not use any
phone in your building.
SImmediately call your gas supplier from a neighbor’s
phone. Follow the gas supplier’s instructions.
SIf 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.
!WARNING
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.
!WARNING
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.
!WARNING
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.
!WARNING
Your rooftop heating/cooling unit is equipped with an
automatic, direct spark ignitor and an induced--draft,
combustion blower.
PERSONAL INJURY HAZARD
Failure to follow this warning could result in personal
injury, death and/or property damage.
Burners will light automatically. Do not attempt to
light by hand.
!WARNING
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.
CAUTION
!
IMPORTANT FACTS
SDO: READ AND UNDERSTAND THIS MANUAL.
SDO: Have your equipment and vent system inspected
annually by a qualified service technician.
SDO: Inspect your filter monthly and clean or replace
when needed.
SDO: Provide adequate airflow to the equipment for
efficient combustion and safe ventilation.
SDO 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.
SDO NOT: Keep combustible materials, gasoline, and other
flammable liquids or vapors around your equipment.
SDO NOT: Cover your equipment in any manner.
SDO NOT: Store anything (including trash or debris)
near your equipment.
SDO NOT: In any way block or restrict airflow around
your equipment.
SDO 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.

3
COMFORTLINK CONTROL
These units have a factory--installed Carrier ComfortLink
control. A Scrolling Marquee display is located in the unit
control box. To ensure complete unit shut off, use the
procedures in this book.
TO LIGHT UNIT
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.
!WARNING
Step 1 —Turn off the unit demand for cooling or
heating by using the Scrolling Marquee (see Fig. 1),
located in the unit’s control box. See Fig. 5 for
control box location.
a. Push the ESCAPE key until a blank display
screen is shown.
b. Push the DOWN arrow key until the SERVICE
TEST LED is lit.
c. Push the ENTER key. The display will show
TEST.
d. Push the ENTER key again. The NO/YES dis-
play will flash.
e. Push the UP or DOWN key to toggle the display
to YES and then push ENTER. The unit will be
locked off from heat, cooling or any operation.
The controls will still function and the display
will still operate.
NOTE: A password may be required to change Service
Test values depending on the previous settings configured
in the unit. The default password is “1111.”
Run Status
Service Test
Temperature
Pressures
Setpoints
Inputs
Outputs
Configuration
Time Clock
Operating Modes
Alarms
Alarm Status
ENTER
MODE
ESCAPE
C06320
Fig. 1 -- ComfortLink Controller
Step 2 —Turn off the gas supply by closing the gas
supply shut--off valve (external to RTU unit). See Fig.
2 for location.
Gas Supply Shut Off Valve
(Field Supplied)
C08485
Fig. 2 -- Gas Supply Shut--Off Valve Location
C07330
Fig. 3 -- Gas Supply Shut Off Valve
Step 3 —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.
LOCK-OUT
TAG
ON
MAIN
OFF
C07331
Fig. 4 -- RTU Main Disconnect -- Electrical Supply
Step 4 —Remove the gas component access panel.
See Figs. 5 and 6.
Gas Component
Access Panel
Filter Access Panel
Control Box
Access Panel
C11482
Fig. 5 -- Typical Access Panel Locations —
48 HC 17 Base Unit Shown

4
C08487
Fig. 6 -- Gas Component Access Panel Removal
Step 5 —Move the RTU gas valve on/off switch to the
OFF position and wait 5 minutes. See Fig. 7.
Two-Stage
RTU gas valve
300k BTU/Hr
Two-Stage
RTU gas valve
On/Off
Switch
OFF
ON
C11483
Fig. 7 -- Two--Stage RTU Gas Valves
Step 6 —Move the RTU gas valve on/off switch to
the ON position.
Step 7 —Replace the gas component access panel.
C08490
Fig. 8 -- Replacing the Gas Component Access Panel
Step 8 —Remove disconnect lockout tag and restore
power to the unit by switching the RTU main
disconnect to ON.
ON
MAIN
OFF
C07336
Fig. 9 -- RTU Main Disconnect -- Electrical Supply
NOTE: Normal operation will automatically begin.
Service Test mode will automatically end (exit) after a
recycle of power.
Step 9 —Open the gas supply shut--off valve located
outside the unit.
C07337
Fig. 10 -- Gas Supply Shut Off Valve
Step 10 —Using the Scrolling Marquee, enable the
unit to run using the following procedure:
a. Push the ESCAPE key until a blank display
screen is shown.
b. Push the DOWN arrow key until the SERVICE
TEST LED is lit.
c. Push the ENTER key. The display will show
TEST.
d. Push the ENTER key again. The NO/YES dis-
play will flash.
e. Push the UP or DOWN key to toggle the display
to NO and then push ENTER. The unit will re-
turn to normal operation and exit SERVICE
TEST mode.
Step 11 —To test the operation of the gas section, use
the Scrolling Marquee test routine to energize the gas
outputs and to turn on the gas.
Run Status
Service Test
Temperature
Pressures
Setpoints
Inputs
Outputs
Configuration
Time Clock
Operating Modes
Alarms
Alarm Status
ENTER
MODE
ESCAPE
C06320
Fig. 11 -- ComfortLink Controller
Step 12 —For normal operation, make sure that the
set points are at the normal heat set points.
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.
!WARNING
TO SHUT OFF UNIT
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 disconnect 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.
!WARNING
Should overheating occur, or the gas supply fail to shut
off, shut off the gas valve in the unit (by moving on/off
switch to off) before shutting off the electrical supply.

5
Step 1 —Turn off the unit demand for cooling or
heating by using the Scrolling Marquee (see Fig. 12),
located in the unit’s control box. See Fig. 5 for
control box location.
a. Push the ESCAPE key until a blank display
screen is shown.
b. Push the DOWN arrow key until the SERVICE
TEST LED is lit.
c. Push the ENTER key. The display will show
TEST.
d. Push the ENTER key again. The NO/YES dis-
play will flash.
e. Push the UP or DOWN key to toggle the display
to YES and then push ENTER. The unit will be
locked off from heat, cooling or any operation.
The controls will still function and the display
will still operate.
NOTE: A password may be required to change Service
Test values depending on the previous settings configured
in the unit. The default password is “1111.”
Run Status
Service Test
Temperature
Pressures
Setpoints
Inputs
Outputs
Configuration
Time Clock
Operating Modes
Alarms
Alarm Status
ENTER
MODE
ESCAPE
C06320
Fig. 12 -- ComfortLink Controller
Step 2 —Turn off gas supply by closing the gas supply
shut--off valve (external to RTU unit). See Fig. 13.
C07330
Fig. 13 -- Gas Supply Shut Off Valve
Step 3 —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.
LOCK-OUT
TAG
ON
MAIN
OFF
C07331
Fig. 14 -- RTU Main Disconnect -- Electrical Supply
Step 4 —Remove the gas component access panel.
For location of the gas component access panel, see
Fig. 15.
C08487
Fig. 15 -- Gas Component Access Panel Removal
Step 5 —Move the RTU gas valve on/off switch to
the OFF position and wait 5 minutes.
Two-Stage
RTU gas valve
300k BTU/Hr
Two-Stage
RTU gas valve
On/Off
Switch
OFF
ON
C11483
Fig. 16 -- Two--Stage Gas Valves
Step 6 —Replace the gas component access panel.
C08490
Fig. 17 -- Replacing the Gas Component Access Panel
Step 7 —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 —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
and take control out of Service Test mode to ensure
operation of the cooling system during the cooling
season.
ON
MAIN
OFF
C07336
Fig. 18 -- RTU Main Disconnect -- Electrical Supply

6
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.
!WARNING
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)
Indoor air filter(s) should be checked every 3 or 4 weeks
(application dependant) and changed or cleaned when
necessary. See Figs. 19 and 20 for air filter access panel
locations. See Table 1 for replacement filter dimensions.
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.
!WARNING
Filter Replacement — 48HC Base Unit
1. Remove the screws securing the filter access panel.
2. While holding filters, tilt upper filter rack.
3. Remove filters by pulling up and out toward you from
the track.
4. Inspect filters. Clean or replace as necessary.
5. Follow direction of airflow arrows as noted on filter
frame when returning filters to rack.
6. Reinstall air filter access panel.
Filter Replacement — ERV Unit
1. Rotate the latches on the ERV access door and open
the door.
2. Slide out the supply and exhaust air filters.
3. Inspect filters. Clean or replace as necessary.
4. Direction of airflow is left to right on the lower filters
and right to left on the upper filters as viewed into the
ERV section when the door is open.
5. Close ERV access door and secure by rotating the
latches.
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.
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.
Table 1 – Replacement Filters -- Size and Quantity
Size Capacity 48HC Base Unit ERV Supply Air Filters ERV Exhaust Air Filters
17 15 tons 20x25x2(6) 20x16x2(2) 20x16x2(2)
20 17.5 tons
24 20 tons 16x25x2(9) 16x25x2(2) 16x25x2(2)
28 25 tons
NOTE: Filter sizes in Table 1 are in inches. Numbers in ( ) denote filter quantity.

7
Gas Component
Access Panel
Filter Access Panel
Control Box
Access Panel
C11482
Fig. 19 -- Typical Access Panel Locations — 48 HC 17 Base Unit Shown
ERV Wheel and
Filter Access Panel
C11499
Fig. 20 -- Typical ERV Wheel and Filter Door Location — 48 HC 17 Base Unit Shown

8
Condenser Fan
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.
!WARNING
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.
!WARNING
Proceed as follows to inspect the combustion area and
power--venting system of your unit.
STurn off gas supply to your unit.
STurn off electrical power to your unit; install lockout tag.
SRemove gas component access panel.
SUsing 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.
CAUTION
!
SWhen 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.
!WARNING
SObserve 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.
SReplace gas component access panel.
ComfortLink Control Alarm Status
The Scrolling Marquee display incorporates an Alarm
Status LED that turns on to indicate an active alarm or
alert. These alarms and alerts are in addition to those that
re indicated by the Integrated Gas Control (IGC). The
ComfortLink control active alarm codes and alarm history
can be viewed with the Scrolling Marquee or other Carrier
Comfort NetworkR(CCN) devices. Alarms may also be
configured to broadcast automatically on CCN. If the unit
will not operate and the Alarm Status LED is on, contact
the local dealer and request service.
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.

9
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.
CAUTION
!
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” RTV, 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.
Evaporator and Condenser Coils
Cleaning of the coils should be done by qualified service
personnel. Thisprocedure shouldbeperformedpriortocooling
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:
SInspection of all flue product passages, including the
burners, heat exchanger, and flue collector box.
SInspection of all combustion-- and ventilation--air
passages and openings.
SClose inspection of all gas pipes leading to and inside
your unit.
SInspection and if required, cleaning of the condenser
and evaporator coils.
SInspection, and if required, cleaning of the condensate
drain pan.
SInspection and cleaning of blower wheel housing and
motor.
SInspection of all supply-- and return--air ducts for leaks,
obstructions, and insulation integrity. Any problems
found should be resolved at the time of inspection.
SInspection of the unit base for cracks, gaps, etc., which
may cause a hazardous condition.
SInspection of the unit casing for signs of deterioration.
SInspection of all electrical wiring and components to
ensure proper connection.
SInspection for leaks in the refrigerant circuit. Pressure
check to determine appropriate refrigerant charge.
SInspection of fan wheels and housings, belt tension, and
fan motor shaft bearings.
SOperational 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.

10
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

11

12
Copyright 2011 Carrier Corp. D7310 W. Morris St. DIndianapolis, IN 46231 Printed in U.S.A. Edition Date: 11/11
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
C a t a l o g N o : O M --- 4 8 H C M X --- 0 1
Replaces: New