Gestra SRL6-50

Description
If the level electrode (high or low level limiter) is installed in
an isolatable level pot outside the boiler, make sure that the
level pot is drained and the connecting lines are rinsed at
regular intervals.
For this purpose the connecting lines must be shut off and
opened at regular intervals and by opening and closing the
drain valve the lines and the level pot will be rinsed.
The logic unit is designed to be used in conjunction with level
switch NRS 1-50 (water level limiter) or level switch NRS 1-51
(high level alarm) to monitor the correct timing and sequence
of valve operations.
During the rinsing process the level switch jumpers the level
electrode, thus preventing the safety or control circuit from
opening. The level switch – controlled by the logic unit – also
monitors the rinsing and bypass time. Function
The logic unit monitors the following times and process se
–
quences:
Interval time: This is the time interval at which, depending
on the operating mode (24h / 72h boiler operation without
constant supervision), the connecting lines have to be rinsed.
During operation the standby time is started after the in
–
terval time has elapsed and the interval time is reset to its
initial value (24h/72h).
During the standby time the connecting lines must be rinsed.
Synchronizing: When valve D or E closes the purging time
starts and the interval time is reset to 24h/72h. The purging
time can start any time. The purging time can also start after
the stand-by time has elapsed.
After the purging time has started the stand-by input of the
level switch NRS 1-50, NRS 1-51 will also be activated.
During the purging time all valves must be opened and
closed in a fixed sequence. The logic unit polls the limit
switches to obtain data on the valve positions and the level
electrode for information on the water level (low level if
electrode is exposed).
If valves D and E are open after the rinsing process and valve
F closed and the level electrode for low water (low level) is
submerged again, the stand-by input of the level switch will
be deactivated.
The stand-by time of the level switch is limited to a maxi
–
mum of 5 minutes. If the stand-by input is not deactivated
by the logic unit during this time, the level switch will open
the safety or control circuit