Operating manual- SAB 355 (including ATEX)
004059 en 2019.11
51/63
Demand oil pump system (optional)
Symptom
Probable cause
Solution
Pump will not pro-
duce enough oil
pressure to start
compressor
Pump rotation.
Check.
Service valves closed.
Open valve.
Filter cartridges may be blocked.
Check pressure difference across
filters.
Strainer may be blocked.
Clean strainer.
Oil pressure regulator set too low or
stuck open.
Readjust or repair.
Pump worn out.
Repair or replace.
Hand expansion valve (pos. 124)
may be opened too much.
Throttle the valve.
Oil pressure rapidly
drops off when com-
pressor starts. Re-
sults in compressor
differential alarm
Main oil injection throttling valve too
wide open or oil pressure regulating
valve improperly adjusted.
Readjust both valves.
Oil pressure
fluctuates
Liquid injection overfeeding or re-
frigerant flood back from system.
Make necessary adjustments or
corrections.
Noise and vibrations
Pump strainer blocked.
Clean strainer.
Liquid refrigerant overfeed.
Adjust liquid injection.
Pump worn out.
Repair or replace.
Grease leaks from
vent port in the side
of the pump body
Normal leakage which will cease
after initial operation. Black oil leak-
ing from this vent indicates oil seal
wear or failure.
If leakage exceeds normal allowable
rate of 7 drops per minute, replace
seal.
Main filter pressure
difference is too
high
Filters clogged with dirt.
Replace filters.
Oil is too cold.
Allow oil to warm up.
Service valve on filter outlet is parti-
ally closed.
Open valves fully.
Table 12: Demand oil pump system (optional)