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2. Use in compliance with regulations
The self-monitoring low water level limiter SMLC1 in combination with the level
electrodes EL 030 or EL 19-2 is a multi-dynamic limiter of a special type in
accordance with DIN VDE 0116 and Wasserstand 100. The self-monitoring
control system (SMC) enables first failure identification at the time of occurrence
and immediately switches off the downstream relays.
3. Function
The general function of the limiter SLMC1 is displayed by lighting of the green
LED “
UB
”. The input stage of the SMLC1 compares the values of the isolation
and limiter electrode in a Wheatstone bridge using a mains synchronised
reference voltage. The dimensioning of this stage allows the identification of
short circuits and interruptions in the electrode power line. The core element of
this limiter is a timer and control unit monitoring the output of the input stage in
the rhythm of 40 ms for its in-phase dynamic behaviour.
If the behaviour is correct the timer and control unit activates the driver of the
final stage with its own momentum. The final stage has its own specified time
which only activates the output relays when phasing and time of the activation
are carried out within a fixed framework. The power flowing via the contacts of
the safety chain is limited in the SMLC1 by 4 amp fuse protection by which
sticking of the contacts is prevented. With static activation or failure of the
activation the final stage will switch off after a delay time.
Faults and lack of water are displayed by the lighting up of the red LED
“FAULT”
. In the case of lack of water after a time delay of one second together
with the display
“FAULT”
the contacts of the additional fault reporting are
closed. After the delay time that can be set at 4, 8, 12, 16 seconds switch-off of
the relays of the safety chain takes place. Locking must be carried out on site.
The delay time is set at 4 seconds.
