Switching Functions Of The Sensor Technology - Kärcher HDS 9/50 De Tr1 Service Manual

9.2.1

Switching functions of the sensor technology

NOTE
The following switching functions serve the general under-
standing of the respective functionality as well as the pos-
sibility how which sensor can be tested.
Emergency stop and cover switch
When operating the emergency stop switch (-S1) or the
cover switch (-S2):
the diesel engine stops immediately.
–
The inverter (-G3) switches off, the electronics is no
–
longer supplied with voltage.
The contactor K7 trips.
–
The emergency stop light (-H3) lights up.
–
Preheating the diesel engine
By turning the key switch to the left, the preheating control
(-H1) lights up for approx. 4 seconds. The preheating takes
place as long as the key switch is kept in the relevant po-
sition, irrespective of the indicator light!
Start process
If the key switch is in the "Start" position, the relay 10KT
(single shot function) receives a start pulse and closes the
contact 15/18 for 10 seconds, the bypass valve K10 re-
sponds.
The start-up process must take place within the 10 sec-
onds:
The diesel engine must run.
–
Inverter and electronics are energized and function.
–
the release contactor K7 is activated.
–
Lock key switch
If you try to turn the key switch to "Start" while the diesel
engine is running (speed >650/min), the starter must not
start. The safety relay K4 prevents the motor start.
Indication charge regulator (-H2)
When switching on the ignition, the lamp H2 lights up (it is
a little brighter after 1 second) and the relay K9 responds.
The lamp H2 goes out within approx. 3 seconds after the
start of the diesel engine. The relay K9 responds and sig-
nals to the electronics via contacts 11/12 that the charge
control is active.
Relay motor oil pressure K5
The relay responds if the oil pressure of the diesel engine
has not built up. As soon as the oil pressure is present, the
relay K5 is released. The checkback signal to the electron-
ics takes place via contact 11/14.
Missing oil pressure (oil pressure switch closed, relay K5
open) leads to a stop of the diesel engine, the fault mes-
sage ERROR 7 appears.
42
English 5.906-736.0 Rev. 00 (07/15)
Indication motor ON/OFF
NOTE
The ON/OFF indication of the motor is controlled via the
signal input of the motor oil pressure switch and the charg-
ing current relay.
Motor oil pressure switch (K5 11/14 open and charging
current relay K9 closed:
Diesel engine is running.
–
Indication ON appears on the display.
–
Motor oil pressure switch (K5 11/14) closed and charging
current relay K9 open:
Diesel engine is not running.
–
Indication OFF appears on the display.
–
Relay coolant diesel engine K6
The relay responds if the coolant in the diesel engine be-
comes too hot. The checkback signal to the electronics
takes place via contact 11/12 (open in case of a fault)
After 4 seconds, the fault leads to a stop of the diesel en-
gine, the fault message ERROR 3 appears.
Charging current / motor oil pressure switch
Charging current relay K9 closed and motor oil pressure
switch open:
Diesel engine is running.
–
Charging current relay K9 open and motor oil pressure
switch open:
Diesel engine stops.
–
ERROR 1 is displayed after 4 seconds.
–
Charging current relay K9 closed and motor oil pressure
switch closed:
Diesel engine stops.
–
ERROR 7 is displayed after 4 seconds.
–
Temperature sensor water in the float container
If the water temperature in the float container is >50?, the
contact S9 11/12 opens.
The temperature exceedance leads to a stop of the diesel
engine, fault message ERROR 3 occurs.
The monitoring of the temperature in the float container as
well as the temperature of the coolant in the motor are se-
rially connected.
Exhaust gas thermostat (-S8)
The exhaust gas thermostat is permanently set to the
switch point 292°C +/-7K. Reclosing after a temperature
drop by 9+/-4.5K.
Exhaust gas thermostat closed:
Device is running.
–
Exhaust gas thermostat open:
Burner blower as well as solenoid valve fuel supply
–
burner (-Y3) are switched off after 4 seconds.
ERROR 9 is displayed after 4 seconds.
–
Level switch liquid softener (-S10)
Level switch open:
Indication "RM 110 empty" in the slide show on the dis-
–
play.
Level switch closed:
Indication "RM 110 OK" in the slide show on the dis-
–
play.