KAESER CSD 75, Service Manual, Page: 79 / 81

Appendix
11 --- 74
Possible cause: Remedy:
Motor is running two phase: defective
motor or blown fuse. Check input power, check wiring, tigh-
ten any loose connections.
Replace fuse(s) or motor if necessary.
Oil separator cartridge is contamina-
ted. Check pressure differential across car-
tridge. Replace cartridge and dirt trap
strainer if necessary.
Motor starts against pressure because
system does not get vented. Check ball valve in vent line and open
if it is closed.
Check the diaphragm in the vent valve
and replace if defective.
Check the minimum pressure check
valve. Adjust minimum pressure func-
tion or replace defective parts as ne-
cessary.
Airend is defective. Check airend and replace if defective.
Ambient temperature is above 104
•
F. Provide adequate compressor ventila-
tion.
Defective motor: bad bearings or short
circuit in windings. Repair or replace motor.
11.3.3 Compressor is running but produces no pressure
Possible cause: Remedy:
Airend rotates in wrong direction. Reverse motor polarity.
Inlet valve does not open or opens
only partially. Check the inlet valve, control valve and
lines. Replace defective parts as
needed
Vent valve does not close at full load. Check the combined control/vent valve
and control lines. Replace defective
parts as needed.
Minimum pressure check valve is de-
fective. Check the valve and replace defective
parts.
Leaks in plant system. Check for open valves, loose connec-
tions, defective tools, etc.
Plant system air, demand exceeds ca-
pacity of compressor Reduce system demand or install
additional compressor(s).
Air leak in unit. Tighten loose connections, repair or
replace defective parts as necessary.
Socket is still in the hose coupling at
the oil separator tank or aftercooler. Remove socket from coupling.
Safety relief valve has blown off. See chapter 11.3.5.
Airend is defective. With unit running, slowly and carefully
place hand over air inlet filter casing.
There should be considerable suction.
If not, airend is producing no pressure.