Kärcher HD 1090 Service Handbook page 7

Unit function
Functional diagram
1 high-pressure hose
2 injector
3 detergent non-return valve
4 detergent metering valve
5 detergent suction hose with filter
6 detergent tank
7 water inlet with non-return valve
8 water inlet hose
9 suction hose with filter and non-return
valve
10 open tank
11 fan wheel
12 motor with cooling coils
13 pump
14 pressure gauge
15 hand gun with Servopress
16 spray lance
17 changeover nozzle
Any unit without a float tank should not be
connected directly to the water inlet. A non-
return valve (7) at the water supply is intended to
prevent detergent from getting into the supply
network.
From the water supply with non-return valve (7),
the water flows through the three cooling coils in
the motor housing (12) to the pump (13).
The pump (13) transports the water through the
high-pressure hose (1), the hand gun (15) and
the spray lance (16) to the changeover nozzle
(17).
Operating pressure and flow quantity can be set
with the hand gun (15).
If the changeover nozzle (17) is set at high-
pressure, the non-return valve (3) seals off the
detergent suction hose (5) to prevent any water
from flowing into the detergent tank (6).
As soon as the metering valve (4) is open and
the changeover nozzle (17) is set at low-pressu-
re, detergent is taken in from the detergent tank
(6) by the injector (2).
In the event of suction from an open tank (10),
the water inlet hose (8) must be replaced by a
water suction hose with filter and non-return
valve (7).
The motor (12) is cooled via the cooling coils in
the motor housing (water cooling) and by the air
current of the fan wheel (11) (air-cooling).
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