Troubleshooting Cooling - Heat Controller BG-81G Service Manual

Service Manual

8.3 Troubleshooting Cooling

PROBLEM
Compressor Low voltage.
does not run.
Thermostat not set cold enough
or inoperative.
Compressor hums but cuts off on
overload.
Open or shorted compressor
windings.
Open overload.
Open capacitor.
Inoperative system switch.
Broken, loose or incorrect wiring.
Fan motor Inoperative system switch.
does not run.
Broken, loose or incorrect wiring.
Open capacitor.
Fan speed switch open.
Inoperative fan motor.
Does not Undersized unit.
cool, or cools
Thermostat open or inoperative.
only slightly.
Dirty filter.
Dirty or plugged condenser or
evaporator coil.
Poor air circulation in area being
cooled.
Fresh air or exhaust air door
open on applicable models.
Low capacity – undercharge.
Compressor not pumping
properly.
Room Air Conditioner with R-410A
POSSIBLE CAUSE
30
TO CORRECT
Check for voltage at compressor. 115 volt
and 230 volt units will operate at 10%
voltage variance
Set thermostat to coldest position. Test
thermostat and replace if inoperative.
Hard start compressor. Direct test
compressor. If compressor starts, add
starting components.
Check for continuity and resistance.
Test overload protector and replace if
inoperative.
Test capacitor and replace if inoperative.
Test for continuity in all positions.
Replace if inoperative.
Refer to appropriate wiring diagram to check
wiring.
Test switch and replace in inoperative.
Refer to applicable wiring diagram.
Test capacitor and replace if inoperative.
Test switch and replace if inoperative.
Test fan motor and replace if inoperative.
(Be sure internal overload has had time to
reset.)
Refer to Sizing Charts.
Set to coldest position. Test thermostat and
replace if necessary.
Clean as recommended in Owner's Manual.
Use steam or detergents to clean.
Adjust discharge air louvers. Use high fan
speed.
Close doors. Instruct customer on use of this
feature.
Check for leak and make repair.
Check amperage draw against nameplate. If
not conclusive, make pressure test.
Heat Controller, Inc.