Vogt P18AL TUBE-ICE, Service Manual

Page: 62 / 88

P18AL Service Manual
TROUBLESHOOTING
3/6/07
8-6
Symptom: High suction pressure (check gage accuracy)
Possible Cause Possible Remedy
Compressor running unloaded or not pumping efficiently Check compressor motor amp. If the compressor is running
unloaded, the amperage will only be approximately 60% of
normal amp draw. Refer to the compressor manual.
Thaw gas valve (18) leaking through Make sure manual opening stem is in the automatic (screwed
in) position. Repair or replace defective parts.
Suction Pressure to low Adjust suction regulator valve
Defective gage Check pressure with accurate gage and replace as necessary.
Symptom: Compressor running unloaded during freeze (dedicated compressor only)
Possible Cause Possible Remedy
Low oil pressure Check compressor net oil pressure.
Net oil pressure = oil pressure gage reading less suction
pressure.
Mycom = 17-28 psig
Vilter = 35-50 psig.
Refer to the compressor manual for “Oil Pressure
Adjustment”.
Unloader solenoid valve open Check solenoid coil to make sure it is not energized. If valve
is stuck open, replace valve.
Unloader mechanism not working properly Refer to compressor manual. Mycom compressor can be
loaded manually.
Symptom: Compressor oil pressure low (check gages)
See Section 7, for compressor oil pressure requirements.
Possible Cause Possible Remedy
Oil diluted with refrigerant Oil will be very foamy. Check liquid feed control for overfeed
problem.
Oil pressure regulating valve out of adjustment Adjust valve to increase oil pressure. Turn stem in to increase,
out to decrease.
Compressor rotation incorrect Check rotation direction by arrow indication. Reverse
rotation, if necessary.
Restriction strainer, oil filter, pick-up tube or oil passage Clean strainer or restriction in passage or replace filter.
Compressor thrust bearing installed upside down The Mycom compressor thrust bearing on the shaft seal end
has an oil passage hole that has to be in the proper position
when installing the thrust bearing. Hole up for “WA” and
“WB” series Mycom compressor. Refer to your compressor
manual.
Symptom: Compressor loosing oil excessively
Possible Cause Possible Remedy
Non-effective oil separator or float The oil separator will normally return a good portion of oil
leaving the compressor, if it is working properly. Check the
oil float and return line to see it is not restricted.
Liquid refrigerant in crankcase Check liquid feed to make sure it is not overfeeding and that
the solenoid valve (25) is not leaking through when the
machine is stopped.
Compressor piston rings seized or broken Check compressor efficiency. If rings are seized or broken,
replace defective parts.
Leaking shaft seal A few drops per minute is okay. If ammonia is leaking,
replace the seal.