Electrical System - Volvo Penta D4 Operator's Manual

Electrical system

The engine is equipped with a two-pole system electrical system which means that the voltage (minus) is returned
directly from the starter motor minus terminal with the battery negative lead. Individual components on the system
return voltage to the starter motor minus terminal via separate cables.
WARNING! Always stop the engine and break the current using the main switches before working on the
electrical system. Isolate shore current to the engine block heater, battery charger, or accessories mounted
on the engine.
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Main switch
The main switch must never be turned off before the en-
gine has stopped. If the circuit between the generator and
the battery is cut off when the engine is running the gener-
ator can be seriously damaged. For the same reason
charging circuits must never be switched over while the
engine is running.
IMPORTANT! Never break the circuit with the main
switches while the engine is running.
Fuses
D4/D6 12-volt system
The engine is fitted with fully automatic circuit breakers.
The circuit breakers cut the power if the electrical system
is overloaded.
If it is not possible to start the engine or if the instrument
stops working while running, the circuit breaker may have
been activated. If the fault is intermittent, resetting will
take place automatically. If the fault persists, read out the
flash codes and take the necessary measures.
IMPORTANT ! Always investigate the cause of the
overload!
D6 24-volt system
The engine is fitted with two automatic circuit breakers
(1). The circuit breakers cut the power if the system is
overloaded.
If it is not possible to start the engine or if the instrument
stops working while running, the circuit breaker may have
been activated. Reset by pressing in the circuit breaker.
If the fault persists, read out the flash codes and take the
necessary measures.
IMPORTANT ! Always investigate the cause of the
overload!
EVC system
The EVC system is protected through the engine circuit
breakers.
IMPORTANT ! Always investigate the cause of the
overload!