Simple Function Test Of The Motor Protection Electronics Without Appli- Ance; Simple Function Test Of The Gentle Start Electronics Inside The Appliance; Replacing The Mains Cable; Gun And Spray Pipe Hd 20/15-4 And 20/15-4 - Kärcher HD 20/15-4 Service Manual

Operation with gentle start

In appliances with gentle start, the trailing must be
active.

When the pressure switch is opened, the pump
will shut off with a 30 second delay.

DIP switch 2: ON = trailing active, OFF = trailing off

Switch the appliance off and back on to delete a
fault display.
5.5.5 Simple function test of the motor protection
electronics without appliance

Connect the indicator lamp.

Use a wire jumper on terminals 3 + 4.

Use a wire jumper on terminals 5 + 6.

Connect a contactor coil to terminals 7 + 8.

Connect voltage (24V~) to terminals 9 + 10.

Switch on the voltage supply.
The contactor must react the indicator lamp must
glow green.
5.5.6 Gentle start electronics
The appliance is equipped with gentle start electron-
ics.
Soft start increases the motor speed gradually to
1,400 1/min and protects the circuit from overloads
when switched on
The electronics can only be replaced as one com-
plete unit. Prior to the replacement, check the cable
connections, connected components and fuses.
A Phase indicator
B Phase indicator
C Voltage supply 24V
D Connection release
E Display "On" lights up for voltage supply of 24V,
display "Run" lights up after the motor has been
started.
Possible reasons for malfunctions of the gentle
start electronics:

Overvoltage of the voltage supply (more than 27V)

Multiple motor starts per minute (30 seconds of
trailing control of the motor protection electronics
is not active).

Corrosion and/or moisture in the components.
5.5.7 Simple function test of the gentle start elec-
tronics inside the appliance

Check whether both phases are present.

Check if the voltage supply (24V~) is present.

Jump the release on X1 5/6 (D top of image).

LED "RUN" on the circuit board lights up after 1 -
2 seconds.

5.5.8 Replacing the mains cable

1 Fastener
2 Disc

Pull out the safety bow of the traction relief.

Loosen the disc.

Take out the traction relief from the holder.

Disconnect the mains cable.

Assemble it back in the reverse sequence.

The disc must be under the safety bow.
5.6 Gun and spray pipe HD 20/15-4 and 20/
15-4
The illustration might differ from the gun on your
model, however, the procedure is still the same.
1 Connection of high pressure hose
2 Hand lever
3 Gun
4 Power press regulator
5 Hand guide
6 Spray pipe (stainless steel)
7 Nozzle
English 5.906-494.0 Rev. 01 (04/11)
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