Fault
Reason
Does not switch
No power
(green LED does not light up)
Electronic defect
Contacts welded together
(after short-circuit)
Measuring transmitter
defective
Switches
Incorrect setting of hook switch
incorrectly
for limit signal
Permanent
Interrupt or short-circuit line to
alarm signal
measuring transmitter
Measuring transmitter
electronics defective
Fail-safe measuring transmitter
FDL 60/61
connected to FEL 67
Switches
FEL 57,
incorrectly after
Behaviour during switch-on
power failure
test (functional test)
Endress+Hauser
Remedy
Check power
Replace FTL 375 P
Replace FTL 375 P;
connect a fuse into contactor
circuit
Replace measuring transmitter
Set hook switch to correct
setting on pcb (p. 15...19)
Check line
Replace measuring transmitter
electronics
Check measuring transmitter
and replace if necessary
Observe switching behaviour
of FEL 57;
after a power failure block
the system control for up to
about 45 s
Trouble-shooting
41