c. Measure the air gap in the regulator.
of the core next to the residual pin should be .115 inch.
Push the armature down until the points open; release
Adjust the air gap by loosening the lock nut and turning
until the points barely close. Measure the air gap at the
the contact screw. Tighten the lock nut after proper
point between the armature and the part of the core next
setting is obtained. Check the current regulator setting
to the residual pan. Do not measure the gap when the
by connecting an accurate ammeter to the leads of the
flat spring that supports the contact screw is raised up off
special wiring harness (fig. 3-7B) in the battery circuit.
the fiber mounting plate. The air gap should be .084
Voltage regulator operation must be prevented during
inch. Adjust by loosening the lock nut and turning the
this check and can be done by partly discharging the
contact screw. This can be done most conveniently by
batter by inserting a carbon pile load approximately the
inserting a flat gage in the gap, pressing down on the
current regulator setting across the battery terminals
armature to hold it in place, and turning the contact
during the current regulator setting test is made. When
setscrew until the contacts barely touch.
the generator output is increased to maximum, the
Check the voltage setting. Insert the special wiring
current should be 38 to 42 amperes, but this must be
harness shown in figure 3-2B leaving the connections
measured before rising battery voltage causes the
open.
voltage regulator to operate. If the voltage is not within
this range, adjust by loosening the lock and eccentric
CAUTION
screw at the base of the current regulator frame. The
Make sure the ends of the leads are insulated. from
eccentric screw increases or decreases the tension of
the ground at all times to avoid a short circuit.
the spiral spring. Increasing the spring tension increases
Connect a voltmeter between the connection from
the relay closing voltage; decreasing the spring tension
the regulator to ground. Cycle the generator as
decreases the closing voltage. When the proper setting
directed in (B) above. With the generator operating
is obtained, tighten the lockscrew. When the proper
at 4,000 rpm and the regulator at operating
setting is obtained, tighten the lockscrew. After each
temperature, note the voltage registered on the
change of adjustment, reduce the generator speed until
voltmeter; it should be between 27.5 and 29.5 volts.
the cutout relay opens; then return to speed and check
If the voltage is not within range.
adjust by
the current indication on the ammeter.
loosening the lock and eccentric screws of the base
of the voltage regulator frame. The eccentric screw
3-7. Installation
increases or decreases the tension of the spiral
a. Secure the voltage regulator to the carrier with
spring. Increasing the spring tension increases the
four bolts and lockwashers.
closing voltage. Adjust to 28.2 volts. Cycle the
b. Connect the electrical leads to the couplings of
generator after each change of adjustment.
the voltage regulator.
d. Measure the gap of the current regulator by the
same method used to measure the air gap of the voltage
regulator. The gap between the armature and that part
Section III. CARRIER ENGINE STARTING MOTOR
pinion of the state into mesh with the ring gear on the
3-8. General
engine flywheel.
The starter is a 24-volt, 4-brush, gear drive type. The
3-9. Removal and Disassembly
starter converts the electrical energy of the batteries into
a. Removal. Refer to TM 5-3810-232-12.
the mechanical energy necessary to crank the engine.
b. Disassembly.
The starter has an overrunning clutch which shifts the
Refer to figure 3-8 and
disassemble the starting motor assembly.
3-12
