Filter
Top Products
28 SXIH-SVX01B-EN
Maintenance
maintenance
procedures
WARNING
Hazardous voltage!
Disconnect all electric power, including
remote disconnects before servicing.
Follow proper lockout/tagout procedures
to ensure the power can not be
inadvertently energized. Failure to
disconnect power before servicing could
result in death or serious injury.
Problem
Insufficient cooling
Possible cause
1. Insufficient air flow due to: a) dirty
evaporator; b) ice on evaporator coils
(indicates airflow restriction through
evaporator); c) dirty filter; d) obstructed
discharge air intake; e) fan motor not
running; f) evaporator fan or fan wheel
slipping on motor shaft
2. Heat gain or loss in room exceeds unit
capacity
3. Defective compressor
4. Insufficient refrigerant charge indicated
by: a) low wattage; b) condenser air outlet
cold
5. Overcharge of refrigerant indicated by
high wattage and sweating of the
compressor return line
6. Thermostat not set for full cooling
7. Insufficient airflow through condenser
due to: a) dirty condenser; b) loose belt;
c) fan loose on shaft
8. Cutout on high pressure
9. Only one refrigerant circuit operational
in 2-circuit units
Problem
Unit short cycles
Possible cause
1. Remote thermostat
2. Loose connection in electrical unit
3. Thermostat contacts fluttering
4. Air flow to evaporator is restricted
5. Insufficient charge
Problem
Compressor starts and runs, but fan does
not run.
Possible cause
1. Faulty switch
2. Open fan motor coil circuit
3. Fan binding on shroud or venturi ring
Remedy
1. Correct as follows: a) clean; b) defrost (using fan operation only); c) clean or replace
filter; d) remove obstruction; e) check electrical system; f) adjust fan position. Tighten
set screw on fan wheel.
2. Refer to original load calculations. Recalculate heat gain or loss.
3. Replace, if necessary.
4. Check refrigerant charge pressure with gauges. If refrigerant is low, recharge
system.
5. Reclaim excess refrigerant.
6. Refer to thermostat operating instructions.
7. Correct as follows: a) clean coil; b) verify drive is adjusted correctly; c) tighten fan on
shaft.
8. See that air is flowing and that damper is set properly.
9. Reset high pressure cutout on inoperative circuit. Check contactor in inoperative
circuit.
Remedy
1. Repair or replace.
2. Trace and repair.
3. Repair or replace.
4. Flush or blow dirt out of coil.
5. Reclaim, evacuate, recharge per nameplate.
Remedy
1. Replace.
2. Replace.
3. Adjust fan mounting.