The electrical backflow value is controlled during operation with
230 V mains voltage. If a power failure results in the system going
offline, then a spring-loaded check valve closes and prevents over‐
flowing of the surge water tank and the running dry of the swim‐
ming pool.
5.3.3 Backflow shut-off valve
Function: Treat the first filtrate in an internal circuit, to ensure suffi‐
cient mixing in the pool, without pumping this first filtrate into the
swimming pool.
Here a valve is opened upon the start of backwashing. The
hydraulic piping should now make possible a direct connection
from the tank (nozzle inlet line) to the suction line. The conse‐
quence of this is that during backflushing a sufficient priming pres‐
sure and a water quantity larger than the capacity of the surge
water tank is available. Upon completion of backwashing, the first
pure water is pumped through the circulating pump into the filter
and thus subject to a cleaning process ensuring that any turbidity
in the swimming pool is excluded. This valve is connected to termi‐
nals
[P2] ... [P7] and then configured in the operating menu of the
Dulcomarin
®
II.
5.4 Lowering the water level
Lowering the water level during standby operation of the water
treatment system
To avoid overflowing of the swimming pool water into the overflow
gutter during standby (evaporation loss and release of chemicals)
and to ensure higher safety of the roll cover under severe weather
conditions (e.g. storm), it is possible to connect a valve to the ter‐
minals
[P2] ... [P7] of the F module. The lower water level is imple‐
mented using a connection line (side bypass or bottom drain) of
appropriate height and a ventilation opening at the top point. The
water volume that is to be lowered flows into the existing surge
water tank where it is stored. The function
‘Lowering of the water
level’ is started by an electrical contact of the roll cover. The con‐
tact input is located on the digital input
[K1] ... [K5].
Electrical backflow valve
Route first filtrate through internal cir‐
cuit
Application examples for the F module functions
20