Section VI. STARTING MOTOR

(4) Close test stand battery switch and operate

(6) Adjust opening discharge current to

generator at 2,500 to 3,000 rpm. Adjust load rheostat or

specified figure by raising or lowering stationary contacts.

lamp bank so ammeter reads one half current regulator

Open test stand battery switch to prevent shorting. Bend

operating amperage.

stationary contact brackets to increase or decrease

contact gap. Increasing contact gap increases opening

Operate at this current for 30 minutes to bring regulator

discharge amperes. Keep contacts aligned for full face

up to operating temperature.

contact and adjust both sets of contacts so they operate

simultaneously. Do not adjust gap between contacts

(5) Place thermometer near regulator to

when open to less than 0.025 inch.

ascertain temperature of 70 . Adjust current to one-half

current regulator setting and read voltmeter and

(7) Open test-stand battery switch.

thermometer. This voltage must be within the limits

specified for voltage regulator for temperature specified.

If voltage is not within limits, stop generator, open tests

i . Voltage and Current Regulator Adjustment.

and battery switch, and remove regulator cover. Turn

adjusting nut on lower end of voltage regulator armature

(1) Remove variable resistance from field

spring until voltmeter reading is within limits. Check this

circuit. Change voltmeter connections so that it is

setting by stopping generator, then operate generator at

connected to regulator base and "Bat" terminal. Connect

2,500 to 3,000 rpm at one-half maximum current. Read

variable load across battery. This load may consist of a

voltmeter and readjust and recheck voltage regulator if

carbon pile or lamp bank.

not within operating limits.

(2) On units that have been completely

(7) Adjust load rheostat or lamp bank so

overhauled, close test stand battery switch and operate

voltmeter reading drops 0.5 to 0.7 volts and read

generator at 2,500 to 3,000 rpm. Hold voltage regulator

ammeter. This reading must be within, limits specified for

contact closed by pressing lightly on back of voltage

current regulator. If current is not within limits, stop

regulator armature and read ammeter. If this is within two

generator and remove regulator cover. Start generator

amperes of correct setting, do not adjust. If current

and adjust current setting by turning thumb nut on lower

setting is not within two amperes, turn adjusting nut on

end of armature spring.

lower end of armature spring. Release voltage regulator

(8) Stop generator and open battery switch.

armature. Stop generator, then start and bring speed up

Install regulator cover.

to 2,500 to 3,000 rpm. Adjust current to one half the

value stamped on regulator nameplate by changing load

(9) Close test stand battery and operate

rheostat or lamp bank. Read voltmeter. If this reading is

generator at one-half current regulator setting for 5

within 0.8 volts units of correct operating voltage, do not

minutes, then check voltage and current settings. Make

adjust. If voltage is not within these approximate settings,

any readjustments that are necessary and finish with a

turn adjusting nut on lower end of armature spring. Stop

final 5) minute run and check.

generator and open

test-stand battery switch.

(3) Install cover gasket and cover regulator.

Section VI. STARTING MOTOR

7-17. General

is cranked electrically. An intermediate duty clutch

The starting motor is a heavy-duty, 24-volt, 4pole, 4-

absorbs high engine torque to prevent damage to the

brush, series wound dc motor located at the lower right

starting motor and the flywheel ring gear during the

side of the engine. When energized by the starting motor

starting period.

solenoid, the pinion gear of the motor drive engages the

7-18. Removal and Installation

flywheel ring gear on the engine, and the engine

Remove and install starting motor as directed in

paragraph 3-48.

7-9