Functional Description Of The Motor Protection Electronics - Kärcher HD 20/15-4 Service Manual


The resistance to spray water is ensured by a seal
on the shaft.

Loosen the 4 fastening screws.

Disconnect the cable connections.

Remove the appliance switch.

Assemble it back in the reverse sequence.
5.5.3 Motor protection electronics
1 Protective conductor connection
2 Measuring coil
3 DIP switch
4 Measuring coil
5 Fuse 1.0 AT
6 Terminal strips
7 Indicator lamp connection
The electronics can only be replaced as one com-
plete unit. Prior to the replacement, check the cable
connections, connected components and fuses.
Connect power supply and control wires according to
the circuit plan.
5.5.4 Functional description of the motor protec-
tion electronics:
Position of the DIP switches:
Switch Position Meaning
1 OFF 1-phase appliance
2 ON Trailing time 30 seconds
3 ON Leak detection
4 ON Switch off after 30 minutes of
continuous operation / pause.
18
English 5.906-494.0 Rev. 01 (04/11)
Display of the indicator lamp:
Blinking Colour Meaning
-- Green Operation, voltage present, no
faults
Dura- Green 30 minutes of continuous opera-
tion tion, continuous pause
1x Red Leak in the system
2x Red Winding protection contact was
triggered
3x Red Over or under voltage, current
asymmetry
4x Red Overcurrent
Switch-off after 30 minutes of continuous opera-
tion or continuous break:

Indicator lamp is blinking green

Machine switches off and locks up, if there is no
signal change from the pressure switch after an-
other 30 minutes.

A signal change will restart the time.

DIP switch 4: OFF = without switch-off, ON = with
switch-off.
Leak

1 blink red.

Switch-off and locking of the machine after 10
short starts (less than 2 seconds) due to a leak.

DIP switch 3: OFF = without switch-off, ON = with
switch-off.
Winding protection contact

blinks red twice:

Switch-off and locking of the machine, if the wind-
ing protection contact opens.
Over or under voltage, current asymmetry

blinks red thrice:

Switch-off and locking of the machine in case the
secondary voltage of the control transformer is
less than 17 volts AC (under voltage).

Switch-off and locking of the machine in case the
secondary voltage of the control transformer is
more than 37 volts AC (over voltage).

Switch-off and locking of the machine in case of a
current difference on the transformers of more
than 10 A for two seconds.
Overcurrent

Switch-off and locking of the machine in case of an
over voltage of 42 A on one of the transformers.
One-phase operation

DIP switch 1: ON = one-phase appliance, OFF =
three-phase appliance.

In the one-phase appliance, only one transformer
is used.