Thermo King KD-II SR, Manual

Page: 163 / 182

149
Electric Standby (Optional) Diagnosis
CONDITION POSSIBLE CAUSE REMEDY
Unit switch ON—µP-T does not
come on Battery discharged Charge or replace battery
Circuit breaker Replace switch if defective
Electric motor reset switch tripping Check for short circuit in unit wiring
(high voltage)
Fuse link blown Replace fuse link
Dirty battery terminals Clean and retighten terminals
Unit switch ON—µP-T comes on
but electric motor does not run No standby power Provide power to unit; check power
at:
1. Power source
2. Power plug
3. Motor contactor hot side
4. Motor contactor load side
(contactor closed)
5. Overload relay
6. Motor terminals
Defective motor contactor Repair or replace motor contactor
Defective low oil pressure sensor Replace low oil pressure sensor
Overload relay tripping Check for shorted motor windings or
wires
Defective motor Replace motor
Batteries discharged Charge ore replace batteries
Electric motor hums but does not
run Locked rotor (overload relay will
open after a period of time)
Remove interference
Locked compressor Repair compressor
Defective clutch on engine (locked
up)
Repair or replace clutch
Low line voltage or no voltage on
one leg
Bring voltage up to within 10% of
motor rating