KNF SCC 950 Operating Instructions Manual page 48

Troubleshooting
Vacuum pump system generally
Error
48 Translation of original Operating Instructions, English, KNF 304771-304773 07/18
Cause
Ventilation valve leaking.
Condensate in pump head.  Open the gas ballast and rinse the
Gas outlet on the high-
performance condenser is
obstructed.
Diaphragms or valve plates
are worn.
Tab. 9 (2nd part)
Vacuum pump system SCC 950
Remedy
 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.
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.
Danger of high-performance condenser
rupturing
 Eliminate blockage of gas outlet.
 Replace diaphragms and valve
plates (Chapter 9.3)