TM 5-3810-207-20/TO 36C23-3-37-12
CHAPTER 4
CRANE ENGINE MAINTENANCE INSTRUCTIONS
Section I. CRANE ELECTRICAL SYSTEM
69. Description
The crane-shovel 24-volt electrical system consists
of two 12-volt batteries connected in series, a starter,
generator, generator regulator, ignition coil, distributor,
spark plugs, lights, gages, and the necessary wiring to
operate all components of the electrical system. The
generator
regulator
prevents
overworking
of
the
generator and overcharging of the batteries. The
ignition coil transforms energy into high tension current
which flows to the distributor and is distributed to the
spark plugs. For proper removal and installation of all
wiring on the crane, refer to the wiring diagram (fig. 1).
70. Batteries, Cables, and Battery Box
a.
Removal.
(1)
Remove the battery box cover (TM 5-
3810-207-10).
(2)
Remove the batteries, cables, and box in
a numerical sequence as instructed on
figure 6.
b.
Cleaning, Inspection, and Repair.
(1)
Clean all parts and inspect for defects.
(2)
Replace defective parts.
c.
Test. Test the batteries with a hydrometer. If
the specific gravity reads below 1.225, recharge the
batteries. Test the batteries after recharging. A fully
charged battery should read between 1.280 and 1.300.
Replace a battery that will not take or hold a charge.
d.
Installation.
(1)
Install the battery box, batteries, and
cables in reverse numerical sequence as
instructed on figure 6.
(2)
Install the battery box cover (TM 5-3810-
207-10).
71. Generator Drive Belt
a.
Removal. Remove the drive belt as instructed
on figure 7.
b.
Cleaning and Inspection.
(1)
Clean
the
drive
belt
with
a
cloth
dampened with an approved cleaning
solvent.
(2)
Inspect the drive belt for cracks, breaks,
and
frayed
or
stretched
condition.
Replace defective drive belt.
c.
Installation. Install the generator drive belt as
illustrated on figure 7.
d.
Adjust the generator drive belt (TM 5-3810-207-
10).
72. Generator Assembly
a.
Removal. Remove the generator assembly as
instructed on figure 7.
b.
Cleaning and Inspection. Clean and inspect the
generator and mounting. Replace defective generator
and mounting.
c.
Installation. Install the generator assembly as
illustrated on figure 7.
d.
Test.
(1)
Hook voltmeter (par. 73).
(2)
Start engine and slowly build up rpm to
operating speed. Observe voltmeter.
The minimum voltage is 27.5 volts.
(3)
If voltage is not built up to required value,
generator is bad; replace generator.
e.
Brush
Replacement.
Replace
generator
brushes as instructed on figure 8.
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