Unit Function
HDS Middle Range / HDS Premium Range
Page 62 / 127
Service Manual 04.2008
2.27 Pressure switch function
1 High-pressure outlet (unpressurised)
2 Pressure gauge (unpressurised)
3 Non-return valve (closed)
4 Rotary knob
5 Overflow valve (closed)
6 Throttle bore
7 Pressure switch, „OFF“ (closed)
8 Water inlet
9 Motor protection contacts (K1) (closed)
10 Pump starts up
11 Pressure switch, „ON“ (closed)
2.27.4 Handgun is reopened with unit
switched on
As soon as the handgun is opened, the pressure
enclosed between the non-return valve (3) and
the handgun escapes. The pressure switch (11)
closes.
This means the control circuit is closed again,
the motor contactor (9) tightens, closes the
contacts, the motor starts up and the pump builds
up the operating pressure again (see circuit
diagram).
1
2
3
4
5
6
7
8
10
11
9
24 volt