between the screw head and spring support and bend the spring upward until contact is made with the
screw head. Always adjust the voltage setting by increasing the spring tension and not by reducing it. If
the current voltage setting is too high, adjust the unit below the required value and then raise to the
exact setting by increasing the spring tension. After each adjustment and before taking voltage
readings, replace the regulator cover, reduce the generator speed until the relay points open, and then
bring the generator back to speed again.
(b) Variable resistance method. Connect an ammeter into the charging circuit at the BAT terminal of the
regulator with a 1/4-ohm variable resistance in series. Connect a voltmeter from the regulator BAT
terminal to the ground. Increase the generator speed to 25 percent above rated output speed. Cut in
the resistance until the output is reduced to 4-6 amperes. Operate the unit for 15 minutes until the
regulator reaches the correct operating temperature to obtain stable voltage and current readings.
Retard the generator speed until the relay points open and then bring the generator back to speed and
note the voltage setting. The voltage reading must be taken with the regulator at operating temperature
and with 4-6 amperes flowing. The voltage regulator cover must be in place. Be sure to readjust the
variable resistance after each voltage adjustment and then reduce and increase the generator speed
before taking the voltage reading.
e. Current Regulator.
(1) Air gap. The correct current regulator air gap is 0.075 inch. The air gap is checked and adjusted in the
same manner as voltage regulator air gap. Refer to d above.
(2) Current setting. To check the current regulator setting, the voltage regulator must be prevented from
operating. If it is necessary to adjust the current setting, remove the cover and adjust it in the same manner
as the voltage regulator (d above) by turning the adjusting screw (13) clockwise to increase the current
setting and counterclockwise to decrease the setting. If the unit is badly out of adjustment, the springs must
be replaced. Four different methods may be used to prevent the voltage regulator from operating. In all
four of the methods, an ammeter must be connected to the charging circuit at the BAT terminal.
(a) Quick check method. Insert a screwdriver blade through the oblong hole in the regulator base (16) until