Carrier 50SD User Manual

50SD

Single-Packaged Electric Cooling Units

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A Guide To Operating and Maintaining Your

Single-Package Electric Cooling Unit

NOTE TO INSTALLER

This manual must be left with the equipment owner.
Note to User: Please read all manuals and retain manuals for

future reference.

FOR YOUR SAFETY

Do not store or use gasoline or other flammable vapors and
liquids in the vicinity of this or any other appliance.

!

WARNING

FIRE, EXPLOSION, ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal

injury, death 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.

Fig. 1—Unit 50SD

!

WARNING

ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal

injury, death.
Before performing recommended maintenance, be sure

the main power switch to unit is turned off.

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 temperature 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 from
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

Before proceeding with those things you might want to
maintain yourself, please carefully consider the following:

ELECTRICAL SHOCK AND CUT HAZARD
Failure to follow this warning could result in personal in-

jury, death or property damage.

1. TURN OFF ELECTRICAL POWER TO YOUR UNIT
BEFORE SERVICING OR PERFORMING MAINTE­NANCE.

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.

EQUIPMENT OWNER

!

WARNING

ACCESS PANEL

FILTER ACCESS
PANEL*

*For accessory filter rack.

Fig. 2—Filter Access Panel—Vertical

Supply Shown

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.

Table 1—Indoor-Air Filter Data

UNIT SIZE FILTER SIZE (IN.)

50SD024-030 20x24
50SD036-060 24x36

!

WARNING

FIRE AND UNIT OPERATION HAZARD
Failure to follow this warning could result in personal

injury, death or property damage.
Never operate your unit without filters in place. An

accumulation of dust and lint on internal parts of your unit
can cause loss of efficiency.

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

!

WARNING

PERSONAL INJURY AND UNIT DAMAGE HAZARD
Failure to follow this warning could result in personal

injury, death or property damage.
Do not poke sticks, screwdrivers, or any other object 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 instrumentation;
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.

!

WARNING

EXPLOSION AND BURN HAZARD
Failure to follow this warning could result in personal

injury, death 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 unit cabinet and to prevent
disruption of the correct unit airflow pattern.

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 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 insulating 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. Pressure­check to determine appropriate refrigerant charge.

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