KNF SC 920G, Operating Instructions Manual

Page: 40 / 48

Troubleshooting Vacuum Pump System SC 920G
40 Translation of original Operating Instructions, English, KNF 121308-121311 07/18
10. Troubleshooting
DANGER
Extreme danger from electrical shock!

Disconnect the pump power supply before working
on the pump.

Make sure the pump is de-energized and secure.

Vacuum pump system as a whole: see table 7.

Hand terminal: see table 8.

Software operation: see table 9.
Vacuum pump system as a whole
Problem Cause Solution
Vacuum pump system is
switched on, but the mains
switch does not light up. Mains cable not plugged in.

Plug the mains cable for the vacuum
pump system into a properly
grounded power socket.
No current in electricity
network.

Check the electricity supply.
Vacuum pump system
fuses blown. 1. Find and eliminate the cause of the
overload.
2. Replace the mains fuse(s) of the
vacuum pump system:

Push the locking clip on the fuse
drawer down (Fig. 3/
4 , p. 12) and
pull the drawer out.

Replace the defective fuse(s)
(for fuse specifications see chapter
4.1, page 8; for fuse order numbers
see chapter 11, p. 45).

Push the fuse drawer back in until it
clicks into position.
Required vacuum not
generated even though pump
is running.
Leaks in vacuum chamber. 1. Run a test by closing the gas inlet
(Fig. 2/ 7 ,p. 11). If the pump reaches
the required vacuum, this confirms
the presence of leaks in the vacuum
chamber.
2. Eliminate leaks in the vacuum
chamber.
O-ring is not sitting
correctly in the slot on the
suction side of the
collection flask.

Adjust O-ring.

Replace if defective (for order
number for O-ring, see chapter 11,
p. 45).
Leaks in hose connection.

Check hoses are sitting correctly on
hose nipples.

Replace any leaky hoses.

Replace any damaged hose nipples.

For ordering numbers see chapter
11, page 45.
Hexagonal gland (Fig. 2/ 8 ,
p. 12) loose.

Carefully tighten hexagonal gland
with wrench.