Heat Controller BG-81G Service Manual page 32

Service Manual
PROBLEM
Unit does Fuse blown or circuit tripped.
not run.
Power cord not plugged in.
System switch in "Off" position.
Inoperative system switch.
Loose or disconnected wiring at
switch or other components.
Thermostat Thermostat contacts stuck.
does not
Thermostat set at coldest point.
turn unit off.
Incorrect wiring.
Unit undersized for area to be
cooled.
Evaporator Dirty filter.
coil freezes
Restricted air flow.
up.
Inoperative thermostat.
Short of refrigerant.
Inoperative fan motor.
Partially restricted capillary.
Compressor Excessive heat load.
runs
continually,
Restriction in line.
does not
cycle off.
Refrigerant leak.
Thermostat contacts stuck
Thermostat incorrectly wired.
Room Air Conditioner with R-410A
POSSIBLE CAUSE
31
TO CORRECT
Replace fuse, reset breaker. If repeats,
check fuse or breaker size. Check for shorts
in unit wiring and components.
Set switch correctly.
Test for continuity in each switch position.
Check wiring and connections.
Reconnect per wiring diagram.
Replace thermostat.
Turn to higher temperature setting to see if
the unit cycles off.
Refer to appropriate wiring diagram.
Refer to Sizing Chart.
Clean as recommended in Owner's Manual.
Check for dirty or obstructed coil - clean as
required or remove obsticales.
Test for shorted thermostat or stuck
contacts.
De-ice coil and check for leak.
Test fan motor and replace if inoperative.
De-ice coil. Check temperature differential
across coil. Touch test coil return bends for
same temperature. Test for low running
current.
Unit undersized. Test cooling performance
of unit. Replace with larger unit.
Check for partially iced coil. Check
temperature split across coil.
Check for oil at silver soldered connections.
Check for partially iced coil. Check split across
coil. Check for low running amperage.
Check operation of thermostat. Replace if
contacts remain closed.
Refer to appropriate wiring diagram.
Heat Controller, Inc.