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11041781.04 01/2020 EN/DE
Pressure gauge with reed contact model 851-A, for Ex areas
EN
Faults
Causes
Measures
Contact is no
longer switching
in accordance with
the specification.
Electrical connection
is interrupted.
Carry out a continuity test
on the electrical connec-
tion lines.
Electrical load unsuit-
able for the switch
contact model.
Maintain the permissible
electrical loads for the
switch contact model.
Contact contami-
nated.
Residual current
protection device
for the circuit is
tripped.
Insulation failure
Replace instrument.
Contact chatter
(repeated,
short-duration
opening and
closing).
Vibrations
Decouple the instrument
mechanically.
No pointer
movement despite
change in pressure.
Movement blocked.
Replace instrument.
For the replacement of the instrument chapters 8 “Dismounting,
return and disposal” and 5 “Commissioning, operation” must be
observed.
6. Faults
