Kärcher HD 1090 How to use

HD 1090
Service Handbook
0
I
5.905-212
03.02

Foreword
Good servicing requires extensive and relevant training as well as comprehensible reference
documents.
We therefore regularly offer all service technicians both basic and ongoing training courses for the
full range of our products.
In addition we produce service handbooks for the major equipment which can be used initially as
instructional material and subsequently as sources of reference.
Furthermore we regularly distribute service information bulletins that provide details about further
developments to the products.
Copying and duplicating texts and illustrations, or passing the contents on to a third party, requires
the express permission of:
ALFRED KÄRCHER GmbH & Co.
CUSTOMER SERVICE TRAINING
PO Box 160
D-71349Winnenden

1
Contents
Unit function ....................................................................................2-15
Equipment.............................................................................................................................. 2
Functional diagram ................................................................................................................ 4
Pump ..................................................................................................................................... 6
Pressure and flow control with the Servopress handgun......................................................8
Detergent injector with non-return valve.............................................................................. 10
Detergent metering valve .................................................................................................... 11
Hand gun with pressure and flow control
Servopress with low-effort version.......................................................................................12
Changeover nozzle.............................................................................................................. 14
Circuit diagram 0.087-804 ...................................................................................................15
Troubleshooting and basic settings............................................. 16-29
Unit does not run ................................................................................................................. 16
Unit does not reach required pressure................................................................................18
Unit switches on and off continuously .................................................................................23
No detergent function .......................................................................................................... 26
Water escaping between cylinder head and housing .........................................................27
Oil escaping between cylinder head and housing .............................................................. 28
Swash plate/shaft sealing ring/motor bearing defective ..................................................... 29
Special tools ....................................................................................... 30
Technical data................................................................................ 31-32

2
Unit function
Equipment
10
15
12
9
10
13
11
14
16
1
8
2
34
5
6
7
0
I

3
1 changeover nozzle
2 spray lance
3 servopress handgun
4 adjusting wheel for pressure and flow control
5 high-pressure hose
6 handle
7 detergent metering valve
8 detergent tank cover
9 detergent tank
10 detergent suction hose with filter
11 hood mounting screw
12 water inlet with strainer
13 high-pressure connection
14 unit switch
15 pressure gauge
16 handle mounting screws
Unit function
Equipment

4
Unit function
Functional diagram
5
3
7
8
9
10
11
12
13
14
2
1
15 16 17
4
6

5
Any unit without a float tank should not be
connected directly to the water inlet. A non-
returnvalve(7)atthewatersupplyisintendedto
prevent detergent from getting into the supply
network.
Fromthewatersupplywith non-returnvalve(7),
thewaterflowsthroughthethreecoolingcoilsin
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).
Operatingpressureandflowquantity canbeset
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
thechangeovernozzle(17)issetatlow-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
themotor housing (water cooling) andby 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

6
Unit function
Pump
15
17
18
1012
13
11
14
16
20
912 11
1
8
2
34
5
6
7
11
1921

7
1 suction valve
2 pressure valve
3 pressure gauge
4 oil reservoir
5 motor shaft
6 shaft seal
7 motor bearing
8 swash plate
9 piston glide shoe
10 piston spring
11 piston
12 oil seal
13 washer
14 low-pressure seal and support ring
15 bushing
16 washer
17 high-pressure seal
18 support ring
19 piston housing
20 O-ring
21 cylinder head
Unit function
Pump
Function
The pump is a 3-piston swash plate pump with
driverunninginanoil bath.Itisdirectlyattached
to the motor shaft, therewith achieving optimal
efficiency. When the piston returns, the water is
taken in via the open suction valve. The advan-
cing piston closes the suction valve and the
water is transported to the nozzle via the open
pressure valve.The operating pressure genera-
teddepends onthediameterofthenozzlebore.

8
Unit function
Pressure and flow control
with the Servopress handgun
1
2
4
3

9
Unit function
Pressure and flow control
with the Servopress handgun
1 Threadedplug
2 Pressure holding valve
3 Spring
4 Ball
5 Valve seat
6 Connecting channel to suction chamber
7 Piston Rod
8 Threadedfitting
9 Spring
10 Pressure switch
11 Locking nut
12 Adjusting nut for pressure switch
13 Locking nut
14 Adjusting nut for operating pressure
15 High-pressure outlet
16 Control pressure injector
17 Connecting channel between injector
and overflow valve
18 Pressure chamber
19 Pressure gauge connection
1. When the Servopress handgun is
opened
When the Servopress handgun is fully opened,
water flows out of the pressure chamber (18),
through the pressure holding valve (2) and injec-
tor (16) then on to the high-pressure outlet (15).
The ball (4) in the overflow valve is pressed
against the valve seat (5) by the pump pressure
and closes off the connecting channel (6) to the
suction chamber. The pressure gauge shows
theoperatingpressurewithinthepressurecham-
ber(18). Theactionof theinjector (16)results in
a pressure level in the connecting channel (17)
that is approx. 30 bar lower.
2. The Servopress handgun is partially
closed
When the handgun is partially closed, the pres-
sure in the pressure chamber (18) does not
increase. Due to the decreased water flow rate,
theeffectoftheinjectoraction(16)isreduced,so
that the pressure in the connecting channel (17)
rises. The pistonrod (7) is pushed to the left
slightlyagainstthespringpressure(9).Thetape-
redtipoftherodpushestheball(4)awayfromits
seat(5)slightly,sothatapartofthepumpflowrate
flows into the suction chamber (6).
Note:
OpeningorclosingtheServopresshandgun
while the cleaner is operating in high-
pressure mode does not result in a change
to the motor current consumption. The
current consumption is only reduced when
the cleaner is being operated in cleaning
agents mode.
3. The Servopress handgun is
completely closed
As the handgun closes, the pressure in the
pressurechamber(18)risesabruptly.Thispeak
of pressure acts upon the pistonrod (7) via the
connecting channel (17) and forces the piston-
rod(7)allthewaytotheleft(approx.4mm).The
taperedtipofthepistonrod(7)pushestheball(4)
completely off its seat, so that the entire pump
flow rate flows through the connecting channel
(6) into the suction chamber.
As soon as the handgun is closed, the pressure
holding valve (2) closes. This trapped pressure
holds the valve in the by-pass mode.
When this position is reached, the pressure
switch (10) is actuated, the electrical supply
interrupted and the motor switched off.
4. The Servopress handgun is opened
If the handgun is opened again, the pressure in
the system drops off abruptly.
The overflow valve is pushed back towards the
right into its original position by the spring. The
pressure switch (10) reconnects the electrical
supply and the motor is switched on again.

10
1 pressure chamber in front of injector
2 injector
3 ball
4 detergent connection
5 spring
6 high-pressure outlet
Unit function
Detergent injector with non-return valve
Detergentcanonlybetakeninifthechangeover
nozzle on the spray lance is set at "CHEM“.
The pressure in the system thereby drops to
approx. 50 bar and the injector generates its
maximum low pressure (approx. 0.8 bar).
The ball (3) of the detergent non-return valve is
lifted out of its seat and detergent is taken in.
With high-pressure operation, the ball of the
non-returnvalvesealsoffthedetergentconnec-
tion,thus preventingany waterfromflowing into
the detergent tank. With high-pressure operati-
on, no detergent can be taken in.

11
Unit function
Detergent metering valve
1 metering knob
2 valve housing
3 spring
4 O-ring
5 metering channel
6 O-ring
7 inlet
8 sealing ring for detergent tank
9 tank lid
10 outlet
Withthissystem,thetanklidandmeteringvalve
are one unit.
In the valve housing, there is a ring-shaped
metering channel, the cross-section of which is
increasing.
The inlet and outlet are connected with this
metering channel. Depending on the position of
the valve housing which can be shifted with the
metring knob, the open cross-section of the
metering channel will change. Thus the amount
of detergent taken in can be continuously mete-
red.
123
6
7
8
4
5
9
10

12
Unit function
Handgun with pressure and flow control (Servopress)
with low-effort version

13
Unit function
Handgun with pressure control and flow control (Servopress) with
low-effort version
1 Spray lance connection
2 High-pressure hose connection
3 Trigger
4 Retention force lever
5 Trigger play
6 Retention force spring
7 Handgun grip covers
8 Trigger position stop lever
9 Stop position in handgun grip
10 Adjusting wheel
11 Bolt
12 O-ring/support ring
13 Spindle
14 Trigger adjusting plate
15 Retaining screw for adjusting plate
16 O-ring/support ring
17 Threaded housing
18 Spring
19 Valve piston
20 Valve seat
Withthistypeofhandgun itispossibletocontrol
thepressure and flowrate continuously, depen-
ding on how far the trigger (3) has been depres-
sed.
The distance that the trigger (3) can move is
limitedbyan adjustablestoplever (8)whichcan
bemovedupwardsordownwardsbyturningthe
adjusting wheel (10).
Theretentionforcelever(4)andspring(6)redu-
ce the retention force when the handgun is fully
opened.
When the trigger (3) is depressed, the valve
piston (19) is away from the valve seat (20) and
against the pressure of the spring (18) by the
spindle (13). This causes a gap to open up
betweenthevalvepiston(19)andthevalveseat
(20). The further the valve is opened, the more
water can flow through.
The distance (5) by which the trigger (3) can be
movedisdeterminedbythepositionofthetrigger
adjusting plate (14).
Iftheadjustingwheel(10)issetto“0”,thetrigger
(3) is locked in the closed position.
Markings on adjusting wheel
21
22
23
21 Handgun closed
22 Handgun partially opened
23 Handgun fully opened

14
Unit function
Changeover nozzle
1 nozzle guard
2 nozzle
3 ball (2x)
4 screw socket
5 marking line
6 union nut
7 fan jet symbol
8 pencil jet nozzle 0°
9 fan jet symbol CHEM
10 fan jet nozzle 25°
11 pencil jet nozzle symbol
12 fan jet nozzle CHEM
The changeover nozzle should be fitted to the
spray lance so that the marking line (5) is at the
top.
Inthisposition,thetwoballsinsidethechangeo-
vernozzlesealthetwouppernozzlessothatthe
water jet always comes out at the lower nozzle.
Themarking linealwaysindicates thesymbol of
the jet concerned. The type of jet is selected by
turningthenozzleguard(1)withthethreenozzles
to the required position, with the hand gun clo-
sed.
123
4
56
7
5
8
9
10
11
12

15
Unit function
Circuit diagram 0.087-804
Q1 motor circuit-breaker with thermal over-
load trip
Q2 pressure switch, 2-pole
M1 3-phase a.c. motor
The model 1.951-261 is reconnectable from
230 V Y (star) to 400 V ∆ (delta).
Fromphases L1,L2 andL3 thevoltage reaches
themotorviaunitswitchQ1andpressureswitch
Q2.
Motor ATB, VEM Motor LS
Start of coil winding Start of coil winding
U1 red U1 black
V1 yellow V1 red
W1 black W1 white
End of coil winding End of coil winding
U2 white U2 yellow
V2 blue V2 blue
W2 grey W2 brown

16
Troubleshooting and basic settings
Unit does not run
Check unit switch
Measure current consumption
Check mains voltage
Electrical connection defective
– Thevoltageindicatedontheratingplatemust
coincide with the mains voltage.
– Check voltage at the socket outlet (all 3 pha-
ses).
– Check main fuse.
Note:
Do not repair any domestic installations
(sockets, etc.)This should only be done by
a qualified electrician.
Extension cable
– The extension cable must always be fully
unwound from the cable drum.
Cable cross-section:
min. 1.5 mm² with up to 10 m in length
min. 2.5 mm² from 10 m to 30 m in length
Motor and unit switch defective
– Theunitswitchhasabuilt-inthermaloverload
trip. If the overload trip has triggered several
times, measure the current consumption un-
der full load at all 3 phases (see technical
data). Replace defective parts if necessary.
An excessive power consumption may be
caused by the following:
– defective motor winding
– defective connecting cable
– extension cord
– fluctuating supply voltage
– Iftheelectricmotorisreplaced,theunitswitch
and pressure switch must also always be
renewed.
– Disconnect the unit from the mains and, with
the unit switch on, measure the electrical
resistance between the connecting terminals
(inlet-outlet).
The desired value must be zero Ohms.
L 1 L 2
L 3
L 1 L 2
L 3

17
Troubleshooting and basic settings
Unit does not run
Overflow valve disassembled
Check pressure switch
Pressure switch defective
– Disconnect the unit from the mains and, with
the unit switch on, measure electrical resi-
stance between the connecting terminals (in-
let-outlet).Inapressurelessstate,thereshould
be zero Ohms (contacts closed).
– Ifnecessary,replacedefectivepartsandreset
the pressure switch (see page 22).
Overflow valve stuck
– If the overflow valve has switched off the unit
via the pressure switch and is then stuck, the
unit will not start.
– Disassemble the overflow valve and check
whetheritmoveseasily.Ifnecessary,replace
defective parts.
– Lubricate all O-rings with silicone grease
6.288-080.
– Adjustment, see page 22.
L 1 L 2
L 3

18
Troubleshooting and basic settings
Unit does not reach required pressure
Disassemble changeover nozzle
Pull out water inlet strainer
Check water supply quantity
Insufficient water supply
– The water inlet hose must be at least 3/4 inch
in diameter.
– Check the water inlet quantity (see technical
data).
Water inlet strainer blocked
– Pull out the water inlet strainer with pliers and
clean. Replace if necessary.
High-pressure nozzle insert washed out
– Disassemble the changeover nozzle. If ne-
cessary replace the nozzle inserts.
Note:
If the nozzle insert is washed out, the unit
cannot build up the full operating pressure.
12
11
10
9
8
7
6
5
4
3
2
1
1
o