Stop the engine if an overspeed condition occurs
during the initial start-up of a new engine or an engine
that has been overhauled.
To stop an electronically controlled engine, cut the
power to the engine and/or shutting off the air supply
to the engine.
i05241031
Electrical System
Never disconnect any charging unit circuit or battery
circuit cable from the battery when the charging unit is
operating. A spark can cause the combustible gases
that are produced by some batteries to ignite.
To help prevent sparks from igniting combustible
gases that are produced by some batteries, the
negative
“
−
”
cable should be connected last from the
external power source to the primary position for
grounding.
Check the electrical wires daily for wires that are
loose or frayed. Tighten all loose electrical
connections before the engine is started. Repair all
frayed electrical wires before the engine is started.
See the Operation and Maintenance Manual for
specific starting instructions.
Grounding Practices
Illustration 13
g03342674
(1) Ground to battery
(2) Ground to starting motor
(3) Starting motor to engine block
Illustration 14
g03342706
(4) Battery to ground
(5) Ground to engine block
(6) Primary position for grounding
Correct grounding for the engine electrical system is
necessary for optimum engine performance and
reliability. Incorrect grounding will result in
uncontrolled electrical circuit paths and in unreliable
electrical circuit paths.
Uncontrolled electrical circuit paths can result in
damage to the crankshaft bearing journal surfaces
and to aluminum components.
Engines that are installed without engine-to-frame
ground straps can be damaged by electrical
discharge.
To ensure that the engine and the engine electrical
systems function correctly, an engine-to-frame
ground strap with a direct path to the battery must be
used. This path may be provided by way of a direct
engine ground to the frame.
The connections for the grounds should be tight and
free of corrosion. The engine alternator must be
grounded to the negative
“
-
”
battery terminal. The
wire used must be adequate to handle the full
charging current of the alternator.
The power supply connections and the ground
connections for the engine electronics should always
be from the isolator to the battery.
14
SEBU8731
Safety Section
Electrical System
