KROHNE CORIMASS G-MFM 4085 EN - Manual (Page 88)

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8.7 Fault finding
Most of the common faults and symptoms experienced with the flowmeter can be resolved with
the help of the following table.
To simplify the use of the table, the faults and symptoms are grouped together:
GROUPS D Display, inputs and outputs
I Current output
P Pulse output
A Alarm output (Status)
E Control input (Binary)
OP Measurement mode and commissioning
ST Commissioning and Start-up of the flowmeter
Please check the following table of hints and advice before
calling your KROHNE Service Department.
Group Fault / Symptom Cause Remedy
Group D
D1 No display or outputs Power not switched on Switch on power
Power supply fuse F9
blown
Replace fuse as per
Section 8.3.1
Fuses F10, and/or
F12 blown
Replace converter as per
Sect. 8.2 or call Krohne
service.
D2 Fluctuating display and
outputs
Time constant too small Increase time constant as
per Section 5.3.
D3 Mass flow display incorrect The wrong values for
parameters CF3 - CF5
programmed. (These are
stamped on the data plate)
Check and correct according
to Sections 5.12 and 5.14.4
Zero calibration Re-do zero, check manual
offset
Primary sensor faulty Check as per Section 8.8
D4 Density display and
outputs not correct
Parameters CF 1-4 incorrect Check the correct according
to 5.12 - 5.14:
Excitation frequency of
primary sensor not correct
when filled with water (see
section 1.2.5)
Check for air in meter. Call
Krohne.
Primary sensor faulty Check as per Section 8.8
Group I
I 1 Connected instrument
displays 0 or negative values
Connection polarity
wrong
Correct as per Sect. 2.3
Connected instrument
faulty or current output faulty
Check output with a mA
meter.
I Test OK
Check cabling and connected
instrument and replace if
necessary.
I Test faulty
Current output faulty. Replace
converter or call Krohne
service.
Group Fault / Symptom Cause Remedy