![background image](http://html2.mh-extra.com/html/karcher/hd-1090/hd-1090_service-handbook_3833971007.webp)
5
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).
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
Summary of Contents for HD 1090
Page 1: ...HD 1090 Service Handbook 0 I 5 905 212 03 02...
Page 4: ...2 Unit function Equipment 10 15 12 9 10 13 11 14 16 1 8 2 3 4 5 6 7 0 I...
Page 6: ...4 Unit function Functional diagram 5 3 7 8 9 10 11 12 13 14 2 1 15 16 17 4 6...
Page 8: ...6 Unit function Pump 15 17 18 10 12 13 11 14 16 20 9 12 11 1 8 2 3 4 5 6 7 11 19 21...
Page 10: ...8 Unit function Pressure and flow control with the Servopress handgun 1 2 4 3...
Page 14: ...12 Unit function Handgun with pressure and flow control Servopress with low effort version...