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2.7.2 Description (see Fig. 2.7)
Operation of the electric circuit In detail
Start button S1 position 1:
Line 2 on 12V contact K3 closed (30-87), lamp H2 is on. K4 excites contact K4 (30-87). Thermocontact element S5 normally
closed, K1 excites contact K1 (30-87).
Use of preheat:
Start button S1 position 1 press pushbutton S8, energizes relay K5 (87-30) and provides power to the glowplug.
Start button S1 position 2:
Line 3 on 12V (override function) hourmeter P1, and fuel solenoid Y1 is excited. Thermocontact engine S2 normally closed,
Fuel level switch S6 closed (full fuel), oil pressure contact S3 open.
Start button S1 position 3:
Start relay K0 is excited and starter motor is running, engine builds up oil pressure and oil pressure contact S3 closes. K3
excited and contact K3 changes over to (30-87). Relay K2 no longer excited, contact K2 opens, lamp H1 goes out. Alternator
also commences supplying voltage and K4 is no longer excited and contact K4 changes over to (87-87a). Lamp H2 goes out,
one can release start button S1 and it returns to position 1. Exciting the safety devices occurs no longer across line 3 but
across line 2 to line 4 and this way to line 3.
Explanation of shutdowns:
Oil pressure contact S3 opens, K3 no longer excited. K3 changes over (87a-87), engine cuts out because fuel solenoid Y1 no
longer excited and lamp H2 goes on simultaneously.
Low Fuel Switch S6 opens, K3 no longer excited. K3 changes over (87a-87), engine cuts out because fuel solenoid Y1 no
longer excited and lamp H2 goes on simultaneously.
Thermocontact S2 opens, K3 no longer excited. K3 changes over (87a-87), engine cuts out because fuel solenoid Y1 no
longer excited and lamp H2 goes on simultaneously.
Thermocontact S5 opens, K1 no longer excited. Contact K1 changes over (87-87a). K3 no longer excited. K3 changes over
(87a-87), engine cuts out because fuel solenoid Y1 no longer excited and lamp H2 and H1 go on simultaneously. Take-over
relay K2 is excited simultaneously with H1 and contact K2 closes (30-87).
Thermocontact S5 cools off and closes, K1 excited again and contact K1 changes over (87-87a
).
However, lamp H1 remains
on across line 9 and contact K2 (30-87).
A fault in the alternator causes terminal D+ to go to 0V and K4 to be excited. Contact K4 changes over to (87a-87), engine
cuts out because fuel solenoid Y1 no longer excited and lamp H2 goes on simultaneously.
