
Visit www.carrier.com
A Guide To Operating and Maintaining Your
Single-Package Electric Cooling Unit
NOTE TO INSTALLER
This manual should be left with the equipment owner.
Do not store or use gasoline or other flammable vapors and
liquids in the vicinity of this or any other appliance. Failure to
follow this warning could result in fire, serious injury, or
death.
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. Failure to follow this warning could result
in electrical shock, fire, serious injury, or death.
50GL
Single-Package Electric Cooling Unit
with Puron® (R-410A) Refrigerant
Before performing recommended maintenance, be sure the
main power switch to unit is turned off. Electric shock could
cause serious injury or death.
TO START UNIT
Step 1—Turn on the electrical power supply to unit.
Step 2—Select temperature and set system switch to
desired mode.
TO SHUT UNIT OFF
If unit is being shut down because of a malfunction, call your
dealer as soon as possible.
Step 1—Set system switch to OFF.
Step 2—Turn off the electrical power supply to unit.
ROUTINE MAINTENANCE
All routine maintenance should be handled by skilled, experienced
personnel. Your dealer can help you establish a standard procedure.
For your safety, keep the unit area clear and free of combustible
materials, gasoline, and other flammable liquids and vapors.
To assure proper functioning of the unit, flow of condenser air
must not be obstructed from reaching the unit. Clearance of at least
36 in. is required from top of unit and 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:
Fig. 1—Unit 50GL
1. TURN OFF ELECTRICAL POWER TO YOUR UNIT
BEFORE SERVICING OR PERFORMING MAINTENANCE. ELECTRIC SHOCK COULD CAUSE SERIOUS INJURY OR DEATH.
2. 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 reduce
sharp edges to a minimum, be extremely careful when
handling parts or reaching into the unit.
AIR FILTERS — Air filter(s) should be checked at least every 3
or 4 weeks 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 1 indicates the
correct filter size for your unit. Refer to Fig. 2 to access the
filter(s).
To replace or inspect filter(s) (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 the filter(s) out of the unit. If
the filter(s) is dirty, clean or replace with new one.
When installing the new filter(s), note the direction of the airflow
arrows on the filter frame.
If you have difficulty in locating your air filter(s), or if you have
questions concerning proper filter maintenance, contact your
dealer for instructions. When replacing filters, always use the same
size and type of filter that was supplied originally by the installer.
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book 1 4
Tab 1b 1a
PC 101 Catalog No. 565-00014 Printed in U.S.A. Form OM50-28 Pg 1 6-00 Replaces: New

ACCESS PANEL
FILTER ACCESS
PANEL*
*For accessory filter rack.
Fig. 2—Filter Access Panel—Vertical Supply
Shown
Table 1 — Indoor-Air Filter Data
UNIT SIZE FILTER SIZE
50GL024-030 20x20x1
50GL036 20x24x1
50GL042-060 24x30x1
Never operate your unit without filters in place. Failure to
heed this warning may result in damage to the blower motor
and/or compressor. An accumulation of dust and lint on
internal parts of your unit can cause loss of efficiency and, in
some cases, fire.
FANS AND FAN MOTOR — Periodically check the condition of
fan wheels and housings 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 only be done by qualified service personnel. Contact
your 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-shipped with a
normal charge of the correct type refrigeration grade oil in them
and should rarely require additional oil.
CONDENSER FAN
Do not poke sticks, screwdrivers, or any other object into
revolving fan blades. Injury or equipment damage may result.
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 instrumentations; therefore, if there are any discrepancies in the operating cycle, contact
your dealer and request service.
REFRIGERANT CIRCUIT — The refrigerant circuit is difficult
to check for leaks without the proper equipment; therefore, if
inadequate cooling is suspected, contact your local dealer for
service.
System under pressure. Relieve pressure and recover all
refrigerant before system repair or final unit disposal to avoid
serious injury or death. 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 unit cabinet and to prevent disruption of
the correct unit airflow pattern.
REGULAR DEALER MAINTENANCE
In addition to the type of routine maintenanceyoumightbewilling
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 and, if required, cleaning of the condenser and
evaporator coils.
2. Inspection and, if required, cleaning of the evaporator drain
pan.
3. Inspection and cleaning of blower wheel housing and motor.
4. Inspection of all supply-air and return-air ducts for leaks,
obstructions, and insulation integrity. Any problems found
should be resolved at this time.
5. Inspection of the unit base to ensure that no cracks, gaps, etc.,
exist which may cause a hazardous condition.
6. Inspection of the unit casing for signs of deterioration.
7. Inspection of all electrical wiring and components to assure
proper connection.
8. Inspection for leaks in the refrigerant circuit. Pressure-check
to determine appropriate refrigerant charge.
9. Inspection of compressor oil level by service person to ensure
proper oil level is maintained in the compressor when it is
installed and running.
10. Operational check of the unit to determine working conditions. 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 50GL 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 SEV-
ERAL EASILY-SOLVED PROBLEMS
If insufficient heating or cooling is suspected:
( ) Check for sufficient airflow. 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. Be sure
the system switch is in the COOL position and not in the OFF
position.
2

( ) 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 and unit performance is still
unsatisfactory, shut off the unit and call your dealer.
Dealer’s Name..................................................................................
Telephone .........................................................................................
Unit Model .......................................................................................
Unit Serial Number..........................................................................
3

Copyright 2000 CARRIER Corp. • 7310 W. Morris St. • Indianapolis, IN 46231 OM50-28
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book 1 4
Tab 1b 1a
PC 101 Catalog No. 565-00014 Printed in U.S.A. Form OM50-28 Pg 4 6-00 Replaces: New