Karcher HD 9-18-4 ST: Proper use

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If the operating time (without interruption of 

work) exceeds an adjustable value (5...120 

minutes), the appliance will shut off.

The motor protection switch switches off 

the device if the power consumption is 

high.

In case of leaks in the high pressure sys-

tem, the appliance is shut off.

After the operation readiness period, a so-

lenoid valve opens in the high pressure 

system and relieves the pressure.

The lack of water fuse in the float container 

prevents the high pressure pump from run-

ning dry in case of a lack of water.

– This equipment produces water under 

high pressure downstream to high pres-

sure cleaning devices.  If required the 

detergent is drawn in and added to the 

water. 

– The high pressure module is perma-

nently installed in a dry, frost-free room. 

The high pressure water is distributed 

through a fixed network of pipes.

Alternatively, a hand spray gun with a 

high pressure hose can be connected 

directly to the high pressure outlet of the 

appliance.

– The high pressure model must be in-

stalled at a wall in such a way that the 

rear opening is sealed by the wall. 

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DANGER

Risk of injury! Follow the respective safety 

regulations when operating at gas stations 

or other dangerous areas.

ATTENTION

Only clean water may be used as high 

pressure medium. Impurities will lead to in-

creased wear and tear or formation of de-

posits in the appliance.

If recycled water is used, the following limit 

values must not be exceeded.

Motor protection switch

Leakage monitoring

Pressure relief (option)

Lack of water fuse (option)

Proper use

Please do not let mineral oil contaminated 

waste water reach soil, water or the sew-

age system. Perform engine cleaning and 

bottom cleaning therefore only on speci-

fied places with an oil trap.

Water quality requirements 

pH value

6,5...9,5

electrical conductivity *

Conductivity 

fresh water 

+1200 

μ

S/cm

settleable solids **

< 0,5 mg/l

total suspended solids *** < 50 mg/l

Hydrocarbons

< 20 mg/l

Chloride

< 300 mg/l

Sulphate

< 240 mg/l

Calcium

< 200 mg/l

Total hardness

< 28 °dH

< 50 °TH

< 500 ppm 

(mg CaCO

3

/l)

Iron

< 0,5 mg/l

Manganese

< 0,05 mg/l

Copper

< 2 mg/l

Active chloride

< 0,3 mg/l

free of bad odours

* Maximum total 2000 

μ

S/cm

** Test volume 1 l, settling time 30 min

*** no abrasive substances

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EN