Flowserve NRR 2-40 - Manual (Page 27)

27
Operation Malfunctions
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Fault-finding list for troubleshooting
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Fault: In spite of correct wiring and commissioning of the equipment an
interference signal is indicated.
Remedy: The interference signal is caused by high-frequency interferences coming
from the installation. For interference suppression we supply ferrite rings,
stock code # 147253. The 230 V supply lines should be looped five to ten
times through the ferrite ring. If several controllers are used in one
system, they can be fed from the interference suppressed supply lines.
For the interference suppression of the bus line we supply hinged-shell
ferrite rings, stock code # 147254. The hinged-shell ferrite rings are
clamped onto the bus line close to the terminal strip of the controller.
Device does not work – interference signal
Fault: Incorrect function at analogue output. The following actual value indicator
shows incorrect values.
Remedy: Correct the switchpoint settings and the control range settings of the
electrode.
Fault: Switchpoints and actual value indication drift continuously towards 100 %.
Remedy: Deposits have accumulated on the electrode rod. Remove the level
electrode and clean the electrode rod.
Fault A high-level alarm is raised although the liquid level is below high level.
Remedy: Deposits have accumulated on the electrode rod. Clean the electrode rod.
Defective electrode insulation. Replace level electrode.
Fault: Liquid level below switchpoint “low level”, device fails to switch.
Remedy: Check installation of level electrode and vent hole in the protection tube.
If an external measuring pot is used make sure to open the isolating
valves.
Fault: “High-level” switchpoint exceeded – no indication.
Remedy: Level switch defective. Replace the equipment.
If faults occur that are not listed above or cannot be corrected, please contact our
service center or authorized agency in your country.
Device fails to function properly
The device works as two-position controller
Fault: Feedback potentiometer defective or not connected.
Remedy: Connect equipment according to wiring diagram. Check feedback
potentiometer.