56
e
Trouble-shooting
Fault
Reason
Remedy
Does not switch
No power
Check power
Faulty signal line
Check signal line
Faulty eletronic insert
• AC (FEL 51) connected directly to
L1 and N
Exchange
• always connect AC (FEL 51) via
external load
Density of liquid too low
Set density to > 0.5 at electronic insert
Fork encrusted
Clean fork
Fork corroded
(Inication on Output: red/yellow
flashes, N2 (FEL 58): green flashes
0.3 Hz)
Exchange fork and process connection
AC (FEL 51):
Internal resistance of
connected relay too
large
Connect suitable relay
AC (FEL 51):
Holding current of
connected relay too low
Connected resistor in parallel with
relay
WA (FEL 54): Contacts welded
together (after short-
circuit)
Exchange WA (FEL 54); put fuse in
contact circuit
Switches
incorrectly
Min-/Max-fail-save mode set wrongly
Set correct mode at electronic insert
Sporadic faulty
switching
Thick heavy foam, very turbulent
conditions, foaming liquid
Mount Vibracon in bypass
Extreme RFI
Use screened cable
Extreme vibration
Decouple, damp, turn fork 90°
Water in housing
Screw cover and cable gland tight
E5 (FEL 52):
Output overloaded
Reduce load, (cable) capacitance