44
English 5.906-548.0 Rev. 00 (04/12)
1 High pressure outlet, shut-off pressure
2 Manometer, shut-off pressure
3 Pressure retaining valve (closed)
4 Pump stands still
5 Rotary knob
6 Overflow valve
7 Throttle bore
8 Pressure switch "OFF" (open)
9 Water inlet
10 Motor contactors (K1) (open)
11 Pressure switch "ON" (open)
Note
The shown functions of the preessure switches and
motor contactor are for understanding purposes only.
In reality, the information from the two pressure
switches is transferred directly to the control electron-
ics, which in turn controls the motor contactor.
There will be brief overpressure in the system when
the gun is closed.
This will open the overflow valve and the entire flow
volume streams into the suction chamber of the
pump through the throttle bore.
As soon as the overflow valve opens, the pressure re-
taining valve closes and the shut-off pressure is
locked between the gun and the pressure retaining
valve.
Due to the locked in shut-off pressure, the pressure
switch remains open.
There will be a pressure backup in front of the throttle
bore, which opens the pressure switch at about 10
bar and thus interrupts the control circuit.
The motor contactors open and the motor is shut off.
As soon as the motor stops, the overflow valve will
close and so will the pressure switch.
However, the motor contactors will remain open as
the control circuit is still interrupted by the open pres-
sure switches.
5.13.3Gun is closed
24
Volt
6
1
3
4
7
8
9
11
5
10
2