SERVICE DIAGNOSIS: Condition - No Ice Being Produced
(Work on each system separately)
STATUS:
GEARMOTOR OPERATES, COMPRESSOR DOES NOT
A. Check the pump down control switch.
1. This pressure switch opens at 0-4 psig, and closes at 14-20 psig. If open check the low side pressure, if
after running the machine the switch opens at a pressure higher than 5 psig, replace the switch. If the liquid
line solenoid valve is open, the low side pressure should be above 20 psig, and the pump down (low
pressure) control should be closed. If the low side pressure is below 20 psig:
a. Check if the
auger
is turning, if it is not, remove the
gearbox
and:
Check for internal damage, repair and replace in the machine.
b. Check for low charge, add some refrigerant, if the unit begins to operate, (normal low
side pressure being about 25 psig) stop and look for a leak, recover, repair, replace the drier,
evacuate, and weigh in the nameplate charge. If, with added charge,
the unit does
not
operate:
Check for a restricted system, recover, replace the drier, evacuate, and weigh in a
nameplate charge.
Check for a
Thermostatic Expansion Valve
that does not open, if defective,
replace it. Recover, replace the drier, evacuate, and weigh in the nameplate charge.
c. Check the liquid line solenoid valve, it should have power to it, if not:
Check the connections on the circuit board. The liquid line (or compressor) relay
on the circuit board may have failed. If so, replace the circuit board.
If there is power to the valve, the coil may be open, or the valve jammed, replace
the valve.
FM2402R
December, 1992
Page 26
