is centered in the air flow of the air
(3) Start the varidrive assembly by sliding
vents in the rectifier compartment, and
t h e safety clip (25-B) off the stop
with the fins of the rectifier vertical
button (25-C) and depress the start
with the flow of air.
button (25-A) (do not depress the
start button more than 10 seconds).
( 9 ) Connect the rectifier to the binding
Note. Let the test stand operate for about
posts in the rectifier compartment, as
1 5 minutes or more (depending on ambient
temperature conditions) to warm-up the gen-
e r a t o r (alternator) and rectifier before pro-
rectifier compartment door.
ceeding with tests in (5) below.
(4) Place the ignition switch (IGN SW)
ternator) is nondirectional, therefore, the
rotation of the varidrive assembly can be in
the 40-ohm 30-ampere maximum
either direction without loss of the generator
rheo-reg switch (21) in the "REG"
d. Test Procedures for Control Units as an
(5) T u r n the speed control handles (22)
slowly clockwise until 2,000 rpm are
(1) The position of switches and controls
(2) through (14) below are listed in
(6) P l a c e the 50-25 fixed load switch
(17-B) to the "ON" position and add
of these items in the position indicated
the 25-12.5 fixed load switch (17-C)
of the table before tests
and 0-25 0-12.5 load switch (17-D).
T u r n the variable load 0-25 0-12.5
Note. The variable volts on-off switch
a m p e r e rheostat (19) clockwise as
(18) is not used in this test, therefore, place
n e c e s s a r y to bring the load up to a
t h i s switch in the "OFF" position.
100-ampere load. Check the load on
(2) Place the battery on-off switch (22)
the load dc ammeter (1).
in the "ON" position and turn the dc
Note. The load switch (17-D) must be in
t h e "ON" position to connect the rheostat
to the "BAT VOLTS" position to de-
( 1 9 ) , also, adjust the rheostat (19) slowly
t e r m i n e whether the battery voltage
until the 100-ampere load is reached. Check
o f the test stand is the same as the
t h e load dc ammeter (1) at the same time
voltage of the system under test. Cor-
and do not allow the ampere reading to
rect voltage is 24 volts or above which
exceed more than 100 ampere.
(7) Test the voltage ouput of each phase
( 4 ) . Place the battery on-off switch
by rotating the ac voltmeter phase se-
( 2 2 ) in the "OFF'" position. If the
l e c t o r switch (14) through the "T1-
reading is less than 24 volts recharge
T2," " T1-T3," and "T2-T3" positions.
b a t t e r i e s (par. 98). After the bat-
The reading on the ac voltmeter (6)
t e r i e s are charged, place the battery
should not differ by more than plus or
on-off switch (22) in the "ON" posi-
minus 1 volt for all three positions on
the ac voltmeter phase selector switch.
c i r c u i t selector switch (10) to the
(8) T e s t t h e a m p e r a g e o u t p u t o f e a c h
"RECT GEN" position. It is also ad-
phase by rotating the ac ammeter
visable to check the batteries with a
phase selector switch (11) through the
h y d r o m e t e r for specific gravity (re-
" P H 1 , " "PH2," and "PH3" positions.
fer to TM 9-6140-200-15).
T h e ampere reading on the ac am-
Note. The safety clip (25-B) must be off
m e t e r (5) should not differ by more
the stop button (25-C) to perform the bat-
than 10 amperes for all three positions
t e r y check in (3) above. Do not push the
s t a r t button (25-A) as the varidrive assem-
b l y need not be running for this test.