KNF SC 920G - Troubleshooting Guide; Power and Vacuum Generation Problems

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.