48HJ004-014
Single-Package Rooftop
Heating/Cooling Units
User’s Information Manual
NOTE TO INSTALLER:
TO LIGHT UNIT
This manual should be left with the equipment owner.
WARNING: If the information in this manual is
not followed exactly, a fire or explosion may
result causing property damage, personal
injury or loss of life.
— Do not store or use gasoline or other flammable vapors and liquids in the vicinity of
this or any other appliance.
— WHAT TO DO IF YOU SMELL GAS
• 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.
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.
If you do not follow these instructions exactly, a fire or
explosion may result. Property damage, injury, or loss of
life could occur.
See Fig. 1A and 1B for location of gas valve. Refer to Fig. 2
while proceeding with the following steps.
Step 1 — Set room thermostat to the lowest temperature
setting and set SYSTEM switch to HEAT or AUTO. position.
Step 2 — Close the manual gas valve.
Step 3 — Turn off the electrical supply to the unit, tag
disconnect.
Step 4 — Remove the compressor access panel.
Step 5 — Move the gas valve switch to the OFF position
and wait 5 minutes.
Step 6 — Move the gas valve switch to the ON position.
Step 7 — Replace the compressor access panel.
Step 8 — Turn on the electrical supply to unit.
Improper installation, adjustment, alteration, service or maintenance can cause property damage,
serious injury or death. Refer to this manual. For
assistance or additional information consult a
qualified installer, service agency, or the gas
supplier.
Before performing recommended maintenance, be sure
main power switch to unit is turned off. Electrical shock
could cause serious injury or death.
Your rooftop combination heating/cooling unit is equipped
with an automatic direct spark ignition and induced-draft combustion blower.
Step 9 — Open the manual gas valve.
Step 10 — Set room thermostat selector slightly above
room temperature to start unit. The induced-draft combustion
air fan will start. Main gas valve will open and main burners
should ignite within 5 seconds. If the burners do not light, there
is a 22-second delay before another 5-second try. If the burner
still does not light, the time delay is repeated. If the burner does
not light within 15 minutes, there is a lockout. To reset the control, break the 24-v power to W1. Repeat Steps 1-10. If burners
still do not light, call for service.
Step 11 — Set the temperature selector on room thermostat
to desired setting.
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. Failure to follow these requirements could result in
serious injury or death.
Do not attempt to light by hand; serious injury or death
may result.
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
PC 111
Catalog No. 534-80017
Printed in U.S.A.
Form 48HJ-2SO
Pg 1
11-00
Replaces: 48GJ,HJ-1SO
Book 1 4
Tab 1a 6a
COMPRESSOR ACCESS PANEL
Refer to Fig. 3 while proceeding with the following steps.
Step 1 — Set room thermostat to lowest temperature setting
and set SYSTEM switch to OFF.
INTAKE LOUVERS
Step 2 — Close the external manual gas valve.
Step 3 — Turn off the electrical power supply to unit;
install lockout tag.
Step 4 — Remove the compressor access panel.
Step 5 — Move the gas valve switch to the OFF position.
Step 6 — Replace compressor access panel.
Step 7 — If unit is being shut down because of a malfuncGAS VALVE
tion, call your dealer as soon as possible.
If unit is being shut down because the heating season has
ended, restore electrical power to the unit and set thermostat to
the COOL position to ensure operation of the cooling system
during the cooling season.
Should overheating occur, or the gas supply fail to shut off,
shut off the manual gas valve to the unit before shutting off the
electrical supply.
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.
FLUE OPENING
Fig. 1A — Gas Valve Location
(48HJ004-007)
MAINTAINING YOUR UNIT
All maintenance should be handled by skilled, experienced
personnel. Your Carrier service technician can help you set up
a maintenance schedule.
For your safety, keep the area around the unit clear and free
of combustible materials, gasoline, and other flammable liquids and vapors.
To ensure proper functioning of the unit, flow of combustion and ventilating air must not be obstructed from reaching
the unit. Clearance of at least 3 ft on flue and condenser sides
and 6 in. on all other sides is required.
Fig. 1B — Gas Valve Location
(48HJ008-014)
TO SHUT UNIT OFF
1. Do not turn off the electrical power to unit without
first turning off the gas supply.
2. Never attempt to manually light the main burners on
unit with a match, lighter, or any other flame. If the
electric sparking device fails to light the main burners,
refer to the following shutdown procedures. Call your
dealer as soon as possible.
Failure to follow these procedures can result in fire, serious injury or death.
2
MAIN
ON
OFF
LOCK-OUT
TAG
STEP 2
STEP 1
STEP 3
SINGLE-STAGE GAS
VALVE
EW
L
O
WR
S
CE CR
2-STAGE GAS VALVE
ON
P3
O
F
F
C2
M1
ON
O
F
F
C
HI
M
REPLA
STEP 4
SINGLE-STAGE GAS
VALVE
48HJD005,006*
48HJE004-006*
48HJF004-006*
48HJD007-014
48HJE007-014
48HJF007-014
EW
WR
L
O
S
CE CR
2-STAGE GAS VALVE
ON
P3
O
F
F
C2
M1
ON
O
F
F
C
M
REPLA
HI
48HJD005,006†
48HJE004-006†
48HJF004-006†
48HJG005,006
48HJH004-006
48HJK004-006
48HJL005,006
48HJM004-006
48HJN004-006
STEP 5
48HJD005,006*
48HJE004-006*
48HJF004-006*
48HJD007-014
48HJE007-014
48HJF007-014
48HJD005,006†
48HJE004-006†
48HJF004-006†
48HJG005,006
48HJH004-006
48HJK004-006
48HJL005,006
48HJM004-006
48HJN004-006
STEP 6
STEP 8
STEP 7
STEP 9
*3-phase units only.
†Single-phase units only.
Fig. 2 — To Light Unit
3
STEP 10
MAIN
ON
OFF
LOCK-OUT
TAG
STEP 1
STEP 3
STEP 2
STEP 4
SINGLE-STAGE GAS
VALVE
EW
L
O
WR
S
CE CR
2-STAGE GAS VALVE
ON
P3
O
F
F
C2
M1
ON
O
F
F
C
HI
M
REPLA
48HJD005,006*
48HJE004-006*
48HJF004-006*
48HJD007-014
48HJE007-014
48HJF007-014
48HJD005,006†
48HJE004-006†
48HJF004-006†
48HJG005,006
48HJH004-006
48HJK004-006
48HJL005,006
48HJM004-006
48HJN004-006
*3-phase units only.
†Single-phase units only.
STEP 5
STEP 6
STEP 7
Fig. 3 — To Shut Unit Off
4
ROUTINE MAINTENANCE AND CARE
FOR THE EQUIPMENT OWNER
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.
Consider the following information before maintaining or
servicing equipment:
.
1. TURN OFF GAS SUPPLY AND THEN ELECTRICAL POWER TO YOUR UNIT AND INSTALL
LOCKOUT TAG BEFORE SERVICING OR PERFORMING MAINTENANCE.
2. Do not turn off electrical power to this unit without
first turning off the gas supply.
3. 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.
4. Failure to follow these instructions could result in
serious injury or death.
Never operate your unit without filters in place. Failure to
heed this warning may result in damage to the blower
motor, compressor and/or evaporator coil. An accumulation of dust and lint on internal parts of your unit can cause
loss of efficiency and, in some cases, fire that could result
in serious injury or death.
Table 1 — Indoor-Air Filter Data for 48HJ
UNIT SIZE
48HJ
004-007
008,009
012,014
INDOOR-AIR FILTERS
(Throwaway Fiberglass)
Quantity
Size (in.)
2
16 x 25 x 2
4
16 x 25 x 2
4
20 x 20 x 2
NOTE: Replacement filters should be UL (Underwriters’ Laboratories) certified or equivalent.
Air Filter(s) — Air filter(s) should be checked at least
every 3 or 4 weeks and changed or cleaned when necessary.
Table 1 indicates the correct filter size for your unit. See Fig. 4
for filter access panel location.
1. Lift up and remove filter access panel.
2. While holding filter, tilt upper filter rack.
3. Remove filters by pulling up and out toward you from the
track.
4. Inspect or replace filters.
5. Return filters t filter tracks. Note direction of airflow arrows on filter frame.
6. Reinstall 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.
FILTER ACCESS PANEL
Fig. 4 — Typical Filter Access Panel Location
(48HJ008-014 Shown)
5
Heat Exchanger
Combustion Area and Vent System — The com-
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.
bustion area and vent system should be visually inspected before each heating season. The normal accumulation of dirt,
soot, rust, and scale can result in loss of efficiency and improper performance if allowed to build up.
This checkout should not be attempted by anyone not having the required expertise and equipment to do the job
properly.
If your unit makes any unusual or especially loud noises
during heating, shut down the heating section and call your
qualified Carrier service technician.
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 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.
See Fig. 1A, 1B, and 5 and proceed as follows to inspect the
combustion area and power-venting system of your unit.
1. Turn off gas supply to your unit.
2. Turn off electrical power to your unit; install lockout tag.
3. Remove compressor access panel.
4. Using a flashlight, carefully inspect the burner areas for
dirt, soot, or scale.
Fans and Belts, and Fan Motor — Periodically check
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.
If dirt, soot, rust or scale accumulations are found, call your
dealer and do not operate your heating section.
Evaporator and Condenser Coils — Cleaning of
5. When you have completed your inspection, follow the
start-up procedures in this manual to restore your unit to
operation.
6. Observe unit heating operation.
the coils should be done by qualified service personnel. 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.
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.
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. Serious injury could
result.
Condenser Fan
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, call your dealer.
7. Replace compressor access panel.
Do not poke sticks, screwdrivers, or any other object into
revolving fan blades. Severe bodily injury could result.
The fan must be kept free of all obstructions to ensure proper cooling. Contact your dealer for any required service.
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.
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.
6
2. Inspection of all combustion- and ventilation-air passages
and openings.
3. Close inspection of all gas pipes leading to and inside
your unit.
4. Inspection and if required, cleaning of the condenser and
evaporator coils.
5. Inspection, and if required, cleaning of the condensate
drain pan.
6. Inspection and cleaning of blower wheel housing and
motor.
7. 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.
8. Inspection of the unit base for cracks, gaps, etc., which
may cause a hazardous condition.
9. Inspection of the unit casing for signs of deterioration.
10. Inspection of all electrical wiring and components to
ensure proper connection.
11. Inspection for leaks in the refrigerant circuit. Pressurecheck to determine appropriate refrigerant charge
12. Inspection of fan wheels and housings, belt tension, and
fan motor shaft bearings.
13. 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.
Fig. 5 — Typical Heat Section Detail
REGULAR DEALER MAINTENANCE
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 Carrier service technician. An
inspection (preferably each heating/cooling season, but at least
every year) should include the following:
1. Inspection of all flue product passages — including the
burners, heat exchanger, and flue collector box.
7
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 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 control access
door.
( ) 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 _________________________________
Copyright 2000 Carrier Corporation
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
PC 111
Catalog No. 534-80017
Printed in U.S.A.
Form 48HJ-2SO
Pg 8
11-00
Replaces: 48GJ,HJ-1SO
Book 1 4
Tab 1a 6a