Carrier 48SD Guide

48SD
Gas Heating/Electric Cooling Units
Visit www.carrier.com User's information Manual
A Guide To Operating and Maintaining
NEATING & COOLING
NOTE: Read the entire instruction manual before starting the
installation.
SAFETY CONSIDERATIONS
Note to Installer: This manual should be left with the equipment
user.
FIRE and EXPLOSION HAZARD
Failure to follow thiw 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.
FIRE, EXPLOSION, ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury,
death and/or property damage.
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 which has
been under water.
For your safety if you smell gas:
1. Do not try to light any appliance.
2. Do not touch any electrical switch: do not use any phone in
your building.
3. Immediately call your gas supplier from a nearby phone.
Follow the gas supplier's instructions.
4. If you cannot reach your gas supplier, call the fire
department.
I , = T
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury
and/or death.
Before performing recommended maintenance, be sure the
main power switch to unit is turned off and lock-out tag
installed.
UNIT INTRODUCTION
This 48SD unit is a small packaged gas heat/electric cooling
system that can provide year-round comfort.
Starting or Shutting Unit OFF
NOTE: Your combination heating/cooling unit is equipped with
an automatic direct spark ignition and power combustion blower.
A99338
Fig, 1-Gas Heating/Electric Cooling Unit
TO START (LIGHT) UNIT:
FIRE and EXPLOSION HAZARD
Failure to follow this warning could result in personal injury,
death and/or property damage.
Do not attempt to light by hand.
FIRE, EXPLOSION, ELECTRICAL SHOCK HAZARD
Failure to follow this hazard 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, famil-
iarize yourself with all the procedures that must be
followed.
Refer to Fig. 2 for location of unit access panel. Refer to Fig. 3 for
location of gas valve. Refer to Fig. 4 while proceeding with the
following steps.
1. Set the temperature selector on room thermostat to the lowest
temperature setting and set system switch to HEAT.
2. (;lose the external manual gas shutoff valve.
3. Turn off the electrical supply to the unit.
4. Remove the front access panel with a 5/I6-in. nut driver.
5. Move the selector switch on the internal gas valve to the OFF
position and wait 5 minutes.
6. Move the selector switch on the internal gas valve to the ON
position.
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book 1h_h__ PC 101 Printed in U.S.A. Catalog No. OM48-29 Pg 1 02-07 Replaces: OM48-20
Tab Ilal 6a

7. Replace the front access panel.
8. Turn on the electrical supply to unit.
9. Open the external manual gas shutoff valve.
10. Set the temperature selector on room thermostat 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 burner does not light
within 5 seconds, the ignition module will go into a Retry
Mode after a period of approximately 22 seconds (following
the 5-second ignition period).
If the burners do not light within 15 minutes of the initial call
for heat, there is a lockout.
11. Set the temperature selector on room thermostat to desired
setting.
FRONT ACCESS
PANEL
Fig. 2-Gas Heating/Electric Cooling Unit A°5175
71_1 /FLUE
A/Hood
BURNERS GAS VALVE
Fig. 3-Gas Heating/Electric Cooling Unit A05147
FIRE and EXPLOSION HAZARD
Failure to follow this warning could result in personal injury,
death and/or property damage.
1. If the main burners fail to light, or the blower fails to start,
shut down gas heating section and call your dealer for
service.
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, then call your dealer as
soon as possible.
TO SHUT UNIT OFF:
FIRE, EXPLOSION. ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury,
death and/or property damage.
Do not turn off the electrical power to unit without first
turning off the gas supply.
NOTE: If unit is being shut down because the heating season has
ended, make sure to turn on power to cooling system.
If unit is being shut down because of a malfunction, call your
dealer as soon as possible.
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 any gas control
which has been under water.
Refer to Fig. 5 while proceeding with the following steps.
1. Set the temperature selector on room thermostat to lowest
temperature setting and set system switch to OFF.
2. (;lose the external manual shutoff valve.
3. Turn off the electrical power supply to the unit.
4. Remove the f}ont access panel.
5. Move the selector switch on the internal gas valve to the OFF
position.
6. Replace the front access panel.
7. Restore electrical power to the unit and set system switch to
COOL to ensure operation of the cooling system during the
cooling season.
OPERATING YOUR UNIT
The operation of your system is controlled by the indoor tempera-
ture control (Thermostat). You simply adjust the thermostat and it
maintains the indoor temperature at the level you select. Most
thermostats of heating and cooling systems have 3 controls: a
temperature control selector, a FAN control, and a SYSTEM or
MODE control. Refer to your thermostat owner's manual for more
information.
To better protect your investment and to eliminate unnecessary
service calls, familiarize yourself with the following facts:
COOLING MODE
With the SYSTEM or MODE control set to COOL, your unit will
run in cooling mode until the indoor temperature is lowered to the
level you have selected, On extremely hot days, your unit will run
for longer periods at a time and have shorter "off" periods than on
moderate days.
GAS HEAT MODE
With the SYSTEM or MODE control of your indoor thermostat set
to HEAT, your unit will run in gas heating mode until the indoor
temperature is raised to the level you have selected. On cold days
and nights, your system will typically run for longer periods of
time and have shorter "off' periods than on moderate days. This is
the same as the COOLING MODE.
MAINTENANCE AND SERVICE
This section discusses maintenance that should be performed on
your system. Most maintenance should be performed by your
dealer. You. as the owner, may wish to handle some minor
maintenance for your new unit.

STEP t STEP2
MAIN
ON
STEP 3
[
STEP 4 STEP 5
STEP6
Hkll
STEP 7
MAINON '_
OFF
STEP8 STEP9
@
STEP t0
Fig, 4-To Start (Light) Unit
3
A05148

STEP 1 STEP 2
MAI N
ON
STEP 3
I
i
STEP 4 STEP 5
IIMAIN ON
1
OFF
STEP 6 STEP 7
Fig. 5-To Shut Unit Off
4
A05149

Table I-Indoor=Air Filter Data
UNiT SIZE FILTER SIZE
48SD024=036 20 × 24
48SD042-060 24 x 36
ROUTINE MAINTENANCE
All routine maintenance should be handled by skilled, experienced
personnel. Your dealer can help you establish a standard proce-
dure.
For your safety, keep the unit area clear and free of combustible
materials, gasoline, and other flammable liquids and vapors.
To ensure proper functioning of the unit, flow of condenser air
must not be obstructed from reaching the unit. Clearance fl'om the
top of the unit is 48 in. Clearance of at least 36 in. is required on
sides except the power entry side (42 in. clearance) and the duct
side (12 in. minimum clearance).
MAINTENANCE AND CARE FOR THE EQUIPMENT
OWNER
Before proceeding with those things you might want to maintain
yourself, please carefully consider the following:
FIRE, EXPLOSION, ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury,
death and/or property damage.
TURN OFF ALL ELECTRICAL POWER TO YOUR UNIT
AND INSTALL LOCK-OUT TAG BEFORE SERVICING
OR PERFORMING MAINTENANCE.
CUT HAZARD
Failure to follow this caution could 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 is taken to keep sharp
edges to a minimum, be extremely careful when handling
parts or reaching into the unit. Wear safety glasses, gloves,
and appropriate protective clothing.
AIR FILTERS
The air filter(s) should be checked at least every 3 months and
changed or cleaned whenever it becomes dirty. Dirty filters
produce excessive stress on the blower motor and can cause the
motor to overheat and shut down. Table I indicates the correct
filter size for your unit. Refer to Fig. 6 to access the filters.
To replace or inspect filters (or accessory filter rack when
supplied):
1. Remove the filter access panel using a 5/16-in. nut driver.
2. Remove the filter(s) by pulling it out of the unit. If the filter(s)
is dirty, clean or replace with a new one.
When installing the new filter(s), note the direction of the airflow"
arrow's on the filter frame.
If you have difl'iculty locating your air filter(s) or have questions
concerning proper filter maintenance, contact your dealer for
instructions. When replacing filters, ahvays use the same size and
type of filter that was supplied, originally, by the installer.
ACCESS PANEL
PI_ERACCESS
PANEL*
*For accessory filter rack
C99050
Fig. 6-Filter Access Panel=Vertical Supply Shown
FIRE AND UNIT OPERATION HAZARD
Failure to follow this warning could result in personal injury,
death or property damage.
Never operate your unit without the filter(s) in place. An
accumulation of dust and lint on internal parts of your unit
can cause loss of efficiency and blower motor and/or com-
pressor damage.
FANS AND FAN MOTORS
Periodically, check the condition of fan wheel and housing and
fan-motor shaft bearings. Contact your dealer for the required
annual maintenance.
HEAT EXCHANGER
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. This
checkout should not be attempted by anyone not having the
required expertise and equipment to properly do the job. Contact
your dealer for the required periodic maintenance.
EVAPORATOR AND CONDENSER COILS
Cleaning of the coils should only be done by qualified service
personnel. Contact your dealer for the required annual mainte-
nance.
CONDENSATE DRAIN
The condensate drain 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-shipped with a normal charge of the
correct type refrigeration grade oil. A compressor should rarely
require additional oil.
CONDENSER (OUTDOOR) FAN
PERSONAL INJURY HAZARD
Failure to follow this caution may result in personal injury.
Do not poke sticks, screwdrivers, or any other objects into
revolving fan blades.
The fan must be kept free of all obstructions to ensure proper
cooling. Contact your dealer for any required service.

ELECTRICAL CONTROLS AND WIRING
Electrical controls are difficult to check without proper instrumen-
tations. If there are any discrepancies in the operating cycle,
contact your dealer and request service.
REFRIGERANT CIRCUIT
The refrigerant circuit is difficult to cheek for leaks without the
proper equipment. If inadequate cooling is suspected, contact your
local dealer for service.
EXPLOSION HAZARD
Failure to follow this warning could result in personal injury,
death and/or property damage.
System under pressure. Relieve pressure and recover all
refrigerant before system repair or final unit disposal. Use all
service ports and open all flow-control devices, including
solenoid valves.
UNIT PANELS
After performing any maintenance or service on the unit. be sure
all panels are fastened securely in place to prevent rain from
entering the unit cabinet and to prevent disruption of the correct
unit airflow pattern.
COMBUSTION AREA AND VENT SYSTEM
The combustion area and vent system should be inspected visually
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 inspection should be done
by a trained service person.
FIRE, EXPLOSION HAZARD
Failure to follow this warning could result in personal injury,
death and/or property damage.
If your unit makes an especially loud noise when the main
burners are ignited, shut down the heating section and call
your dealer.
PERSONAL INJURY HAZARD
Failure to follow this caution may result in personal injury.
Components in heating section may be hot after unit has been
started up. When observing flame, be careful not to get close
to or touch heating components.
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 service technician. An inspection (preferably each year, but
at least every other year) should include the following:
1. Inspection of all flue product passages-including the burners,
heat exchanger, and flue collector box.
2. Inspection of all combustion- and ventilation-air passages and
openings.
3. Close inspection of all gas pipes leading to and inside of your
unit.
4. Inspection and, if required, cleaning of the outdoor and indoor
coils.
5. Inspection and, if required, cleaning of the indoor coil
condensate drain.
6. Inspection and cleaning of blower wheel housing and motor.
7. Inspection of all supply-air and return-air ducts for leaks,
obstructions, and insulation integrity. Any problems found
should be resolved at this time.
8. Inspection of the unit base to ensure that no cracks, gaps, etc.,
exist 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. Pressure-check
to determine appropriate refrigerant charge.
12. Operational check of the unit to determine working condi-
tions. Repair or adjustment should be made at this time.
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.
WARRANTY CERTIFICATE
Unit 48SD has a limited warranty. Be sure to read the warranty
carefully to determine the coverage for your unit.
BEFORE YOU CALL FOR SERVICE ...
...check for several easily-solved problems.
If insut_cient heating or cooling is suspected:
( ) Check the air filter for dirt.
( ) Check for blocked return-air 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
below the indoor temperature during the cooling season or
above the indoor temperature during heating season. Be sure
the SYSTEM switch or MODE control is in the COOL or
HEAT position and not in the OFF position.
( ) 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 ser-
vice call.
IN CASE OF TROUBLE
If you perform the steps above and the unit pertbrmance is still
unsatisfactory, shut off the unit and call your dealer.
Dealer's Name
Telephone
Unit Model
Unit Serial Number
Copyright 2007 CARRIER Corp. Y 7810 W. Morris St. Y Indianapolis, IN 46231
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
PC 101 Printed in U.S,A, Catalog No. OM48-29 Pg 6 02-07 Repiaces: OM48-20