Operation, 3 fault diagnosis and corrective action – KROHNE BM 500 EN User Manual
Page 17

OPERATION
5
17
BM 500
www.krohne.com
12/2013 - 4003176301 - MA BM 500 R02 en
5.3 Fault diagnosis and corrective action
INFORMATION!
•
In the event of a fault or malfunction, please go through the various possible faults listed in
the table.
•
Please do not attempt to take the device apart.
•
There are no parts requiring maintenance.
Fault
Cause
Action / elimination
LED status display not "on"
Supply voltage < 18 V
Measure voltage at pin 1, 2.
Supply voltage has false polarity
Note: The level meter is polarity
protected. No damage to the
electronics will occur when the
wiring was accidently reversed.
Reverse terminals 1, 2.
Current output < 4 mA
Sensor "dry"
OK
Conductivity too low
4 mA adjustment
No connection to metal
Check connection to frame /
thread
Measured value incorrect
Adjustment faulty
Adjust 4 and 20 mA settings or
factory reset
Poor connection to frame
Check connection to frame /
thread