IM-P693-06
EMM Issue 1
20
LCS3050 Low Water Level Switch for two probes
6.4 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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Make sure that connecting cables leading to the level probes are segregated and run separately from
power cables.
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Increase the distance to sources of interference.
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Check the connection of the screen to the central earthing point (CEP) in the control cabinet.
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HF interference suppression by means of hinged-shell ferrite rings.
6.5 Interlock and interlock deactivation
In the event of an alarm the level switch LCS3050 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 50156.
6.6 Checking the switchpoints
To check the switchpoint “Low water (LW)” you have to lower the water level. When the water level falls
below the probe 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 probe enters the water again. In this case the LEDs for alarm 1 and
2 must be illuminated and no malfunction must be indicated (diagnosis LEDs are not illuminated). Always
check the switchpoint when commissioning the equipment, after replacing the level probe and at regular
intervals, e.g. every year.
6.7 Decommissioning/replacing level switch
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Switch off supply 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.
See Figure 2.
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Release the white fixing slide at the bottom of the equipment and take the equipment off the supporting rail.
6.8 Disposal
For the disposal of the level switch observe the pertinent legal regulations concerning waste disposal.
