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Deutsch
5.962-786.0 Rev. 05 (06/13)
The water flows back from the swimmer tank to the
suction side of the pump. The water level in the swim-
mer tank is kept constant by the swimmer valve. In
case of failure of the swimmer valve, the water exits
via the overflow. If the water supply is disturbed, the
lack of water fuse will send an error message to the
controls.
The electric engine will drive the crankshaft pump.
The pump transports the water under high pressure
to the pressure side.
The high-pressure water reaches the high-pressure
output via the overflow valve and the pressure sen-
sor. After that, there will be the high-pressure network
of the operator.
Remaining water will be routed back to the suction
side of the pump by the overflow valve. If all consum-
er loads have been switched off, the overflow valve
will switch to circulation. If the pressure at the output
exceeds the maximum operating pressure at the out-
put, the safety valve will open.
–
The appliance will be switched to READY mode by
activating the release switch. The indicator lamp
for operational readiness lights up. If the pressure
in the systems sinks below the determined switch-
on point due to the opening of a hand spray gun,
the high-pressure pump will be switched on.
–
HDC 20/8: If the flow monitor in the high-pressure
line is triggered while the pump is running after
closing all hand sprayguns, the pump is switched
off once again with a 10 second delay.
–
HDC 20/16: If the pressure switch at the overflow
valve is triggered while the pump is running after
closing all hand sprayguns, the pump is switched
off once again with a 30 second delay.
–
If the system is ready and the high-pressure is not
turned on, a timer is started, which will reset the
readiness of the unit after 6 hours. The operation
readiness indicator lamp goes off.
Safety devices serve for the protection of the user
and must not be put out of operation or bypassed with
respect to their function.
The safety mechanism against lack of water prevents
the high pressure pump from being switched on when
there is no water.
The temperature sensor switches off the appliance
as soon as the water temperature is too high.
The winding proctection contact in the motor winding
of the pump drive switches off the engine when there
is a thermal overload.
–
The safety valve opens when the overflow valve is
defective.
–
The safety valve is set by the manufacturer and
sealed. Setting only by customer service.
–
If the hand spray gun is closed, the overflow valve
opens and the entire water volume will flow back to
the pump suction side.
–
HDC 20/16: If the hand spray gun is closed, the pres-
sure switch switches off the pump after approx. 30
seconds of trailing time.
–
The overflow valve and pressure switch are set and
sealed at the factory. Setting only by customer ser-
vice.
The general function of an overflow valve is the protec-
tion of the high-pressure unit as well as the protection
against ruptures of the line network in case of an exces-
sive pressure increase. If the system pressure exceeds a
maximum value (system pressure) defined in advance,
the valve opens and the excess water volume is led back
to the pump or into a storage tank. This means that the
HP unit does not continuously need to work against an
excessively high pressure in the line network! The over-
flow valve should be set to 5% above the maximum ad-
missible system pressure.
Possible reasons for a pressure increase are, for exam-
ple:
Clogged nozzles at the extraction points
The switch-off of a nozzle, for example, after cleaning
has been completed (see following drawings)
Pressure increase with variation of the working pres-
sure at the spray lance
In case of an HD unit of the Advanced series with inte-
grated frequency control, the overflow valve is merely
opened in the first moment of a sudden increase of the
system pressure. The reason for this is the required reac-
tion time until the frequency control intervenes and ad-
justs the pump frequency to the actually required delivery
rate.
This means only suddenly occurring pressure peaks are
compensated via the overflow valve at the beginning until
the HD unit adjusts itself. This leads to a lower water con-
sumption and a longer service life of the pumps and the
overflow valve.
The following example is to illustrate the function of an
overflow valve by reference to a closing extraction point.
It merely shows on possible version. (With the HDC
Advanced series, for example, a central overflow
valve for all pump units is used).
3.2.2
Water inlet
3.2.3
Pumps
3.2.4
High pressure side
3.2.5
Pressure regulation
3.2.6
Controls
3.3
Safety Devices
3.3.1
Safety mechanism against lack of water
in swimmer tank
3.3.2
Temperature sensor
3.3.3
Winding protection contact
3.3.4
Safety valve
3.3.5
Overflow valve with pressure switch