Karcher HD 6000 C - Manual (Page 12)

HD 4000 C / HD 6000 C English
5.956-648 A10369 (06/98)
2. Description of Functions
Water Inlet
The water is conveyed from the float
reservoir to the intake side of the two
pumps. The water level in the float
reservoir is maintained by the float valve
(2). The incoming water is cleaned in the
dirt trap (3). In the case of a float valve
failure, the water exits through the overflow
(4). In the event of insufficient feed water
volume or failed water supply the low-water
sensor (5) sends a fault signal to system
control.
Pumps
The electric motor drives both pump ends
(1). The pumps convey the water under
high pressure to the pressure side. The
starting of the motor opens the pressure
relief valve with its upstream filter (7). This
action connects pressure and suction sides
of the pumps, and no pressure is built up.
The motor is able to start free of any load.
High-pressure side
The high-pressure water passes through
the overflow valve (8) and the flow monitor
(9) to the high-pressure outlet, and
subsequently into the high-pressure tubing
system installed by the system owner. The
dashpot (13) dampens the water pressure
pulsing through the piston sleeve.
Pressure Control
Unused water is returned from the overflow
valve to the float reservoir. If all utilisers
are inactive, the overflow valve switches to
idle-pressure circulation. If the outlet
pressure exceeds the maximum operating
pressure regardless of the overflow valve,
the safety valve (10) opens.
System Control
The pump motor is started with the unlock
button (S1). If the volume of water taken
drops below 8 +2 litres per minute, then the
after running time starts. This amounts to
about 15 seconds. If the water consumption
remains below the minimum quantity, then
the pump stops after expiry of the after
running time. Within the immediately
following availability time the pump starts
due to the drop in pressure caused by the
opening of a handgun or by activation of
the unlock button. If the water pressure
drops due to leakages in the high-pressure
network then the pump starts and executes
leakage compensation. The availability time
ends
n
after approx. 6 hours,
n
after six attempts at leakage
compensation,
n
after the switching off of the supply
voltage.
After expiry of the availability time the
system can only be restarted with the
unlock button.
Cooling
During the operation of the pump the
solenoid valve (11) is kept in the open
position. This allows cooling water to flow
through the pressure regulator (12) and
circulate through the cooling coils of the
motor. The flow of cooling water is set by
means of the pressure controller. Once the
cooling water has passed through the
cooling coils it is returned to the float
reservoir.
C2
C. System Function