Flowserve NRS 1-50 For TWO Electrodes - Manual (Page 24)

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Action against high frequency interference
Should sporadic failures occur in installations susceptible to faults (e. g. malfunctions due to out-of-
phase switching operations) we recommend the following actions in order to suppress interferences:
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Provide inductive loads with RC combinations according to manufacturer's specification to ensure
interference suppression.
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Increase the distance to sources of interference.
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Check screens and shields.
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HF interference suppression by means of hinged-shell ferrite rings.
Further Notes
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Switch off mains voltage and cut off power supply to the equipment.
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Unscrew the right and left fixing screws 3 and remove the upper and lower terminal strips 1 2 ,
Fig. 6
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Release the white fixing slide at the bottom of the equipment and take the equipment off the
supporting rail.
Decommissioning / replacing level switch
Disposal
For the disposal of the level switch observe the pertinent legal regulations concerning waste disposal.
In the event of an alarm the level switch NRS -50 does not interlock automatically.
If a lock function is required by the installation it must be provided in the follow-up circuitry (safety
circuit). The circuitry must meet the requirements of the EN 5056.
Interlock and interlock deactivation
To check the switchpoint “Low water (LW)” you have to lower the water level. When the water level
falls below the electrode tip, the level switch must activate an alarm and the safety circuit must open
as soon as the de-energizing time delay has elapsed. The switching-off of the heating is interlocked in
the safety circuit and can only be deactivated when the level electrode enters the water again. Always
check the switchpoint when commissioning the equipment, after replacing the level electrode and at
regular intervals, e.g. every year.
Checking the switchpoints
Note on the Declaration of Conformity / Declaration by the Manufacturer
For details on the conformity of our equipment according to the European Directives see our
Declaration of Conformity or our Declaration of Manufacturer.
The current Declaration of Conformity / Declaration of Manufacturer are available in the Internet under
www.gestra./de/documents or can be requested from us.