Troubleshooting
Vacuum pump system SCC 950
48
Translation of original Operating Instructions, English, KNF 304771-304773 07/18
Vacuum pump system generally
Error
Cause
Remedy
Ventilation valve leaking.
Temporarily close the ventilation
connections (Fig. 2/
16
and
19,
p.
13). If there is no leak when the ven-
tilation connection is closed, the ven-
tilation valve has a leak. In this case:
Rinse the ventilation valve:
1. Close gas inlets (Fig. 2/
17
and
18
).
2. If necessary for safety reasons:
Connect inert gas to the ventilation
connection. The safety precautions
in Chapter 3 must be observed at all
times.
3. Run the vacuum pump system in
Evacuate
operating mode with the
pump at full speed
4. Open the gas inlet again.
If the problem remains, contact KNF
Service.
Condensate in pump head.
Open the gas ballast and rinse the
pump heads.
Dry the system with fresh air or, if
necessary for safety reasons, with
an inert gas:
1. If inert gas is used: Connect an inert
gas source to the gas inlets (Fig.
2/
17
and
18,
p. 13) and start the sys-
tem in Evacuate operating mode
(100% speed). The safety precau-
tions in Chapter 3 must be observed
at all times.
2. If air is used:
Open gas inlets (Fig. 2/
17
and
18,
p. 13) to the atmosphere and start
the system (SC 950: in Evacuate
operating mode) (100% speed).
3. After 30 seconds, close the gas inlet
and run the vacuum pump system
for 30 seconds in vacuum.
4. Repeat 3-5 times.
If the problem occurs frequently:
Place the vacuum pump system
higher than the vacuum chamber.
Gas outlet on the high-
performance condenser is
obstructed.
Danger of high-performance condenser
rupturing
Eliminate blockage of gas outlet.
Diaphragms or valve plates
are worn.
Replace diaphragms and valve
plates (Chapter 9.3)
Tab. 9 (2nd part)
