Section XII. ELECTRICAL SYSTEM
(3) Repair by replacing defective cables or
3-80. General
battery.
a. For Crane Units with engine Model 687C18-ES.
3-82. Battery Box
This 24 volt electrical system consists of two 12 volt
a. and Installation.
batteries connected in series, A belt driven battery-
(1) Non-winterized units.
lights, generator voltage regulator, trouble light, oil
pressure transmitter, water temperature transmitter, low
oil pressure switch, water high temperature switch, and
and remove battery box.
An overspeed governor driven through
(c) Install in reverse order.
tachometer drive, actuates the shutdown lever on
(2) Winterized units.
injection pump through a microswitch controlled circuit
when engine overspeeds the predetermined limit. The
cranes are also equipped with a horn and floodlights,
3 and 4, and remove battery box.
and the winterized units have windshield wiper, engine
(c) Install in reverse order.
heater, battery heater, and personnel heater. See wiring
b. Insulation Panels (Winterized Units). Refer to
schematic diagrams (view A, fig. 1-10 through view G).
b. For
Crane
Units
with
engine
Model
panels. Install in reverse order.
D3S3TA.This unit is equipped with battery-charging
3-83. Generator and Belt (For Engine Model 687C-
alternator and alternator voltage regulator instead of
1 8-ES).
generator and generator voltage regulator. It is not
a. Equipment Test of Generator.
equipped with the microswitch overspeed governor
(1) Field current test. Refer to figure 3-71,
shutdown circuit, but has a low fuel pressure switch
remove shielded cable, and inspection band, from
mounted on clean side of fuel filter that is normally open
generator.
to prevent electrical current from flowing back to the
(a) Use automotive generator and
alternator when engine is stopped, and cause damage to
voltage regulator test set as illustrated in view A of
rectifiers in alternator or transistors in regulator. See
wiring schematic diagram (view G, fig. 1-10)
c. Organization Maintenance Procedures. This
voltmeter reads 24 volts.
section will outline and illustrate organizational
Note. Batteries must be fully charged for this
maintenance procedures authorized by the maintenance
test.
Allocation Chart (Appendix C).
3-81. Batteries
should be from 1.00 to 1.05 ampere.
a. Removal and Installation.
(d) When readings do not meet
(1) Non-winterized units.
requirements of (b) and (c) above, generator is
(a) Refer to figure 3-68, perform steps
defective and must be replaced.
1 and 2, and remove batteries.
(2) Motoring test.
Connect test set as
(b) Install in reverse order.
illustrated in view B of figure 3-72.
(2) Winterized units.
(a) Adjust variable resistor to maximum
(a) Refer to figure 3-69, perform steps
resistance.
1 and 2, and remove batteries.
(b) Close battery switch then gradually
(b) Install in reverse order.
reduce resistance until armature begins to rotate.
b. Cleaning, Inspection, and Repair.
It should rotate freely.
(1) Clean batteries with an approved cleaning
(c) When armature fails to rotate freely,
solution and dry thoroughly. Remove all corrsion from
generator is defective and must be replaced.
battery cables and terminal posts.
(d) Remove test set, install inspection
(2) Visually inspect battery cases and vent
band, and replace shielded cable.
caps for cracks, or terminals for looseness. Use a
b.
Removal and Installation.
hydrometer and test electrolyte for specific gravity.
(1) Tag and remove all electrical leads.
Charge, or replace a battery reading less than 1. on
(2) Remove
capscrew
from adjusting
hydrometer.
bracket, move generator toward engine block and
remove belt from pulley.
(3) Remove two capscrews, washers and
3-81
