ment of the vibrating reed of the
1 - Place in the "50A (X1)" position for the
no load (free running test).
2. Slide the knurled sleeve on the ta-
2 - Place in the "100A (X3)" position for
chometer to extend the vibrating
the stall torque measuring stall cur-
rent and torque) test.
3. Adjust the vibrating reed outward
Place the load
dc ammeter starter
and inward until the reed reaches
test selector switch (fig. 61) in the
its maximum swing (or vibration).
"free run (X4)" position.
Starter speed (rpm) is indicated on
(c) Place the battery on-off switch (22)
in the "ON" position and turn the dc
edge of the knurled sleeve closest to
voltmeter circuit selector switch
(10) to the "BAT VOLTS" position
(g) The speed for the starter (cranking
to determine whether the battery
m o t o r ) should be approximately
voltage of the test stand is the same
as the voltage of the system under
(h) Place the starter test load discon-
test. Correct voltage is 24 volts
nect switch (15) in the "OFF" po-
which will be indicated on the dc
sition and note the rotation of the
pinion gear of the starter (cranking
24 volts recharge batteries (par.
motor) as it comes to a stop. Record
98). It is also advisable to check the
this information for the stall torque
b a t t e r i e s with a hydrometer for
(measuring stall current and
specific gravity (refer to TM 9-
torque) test in c below.
(i) Place the battery on-off switch (22)
in the "OFF" position and adjust
N o t e . The safety clip (25-B) must be
off the stop button (25-C) to perform the
the starter carbon rheostat (fig. 60)
b a t t e r y check in (c) above. Do not push
t h e start button (25-A) as the varidrive
rotating it in the counterclockwise
assembly need not be running for this test.
direction until a slight drag or pres-
(d) Let the battery on-off switch (22)
sure is felt.
remain in the "ON" position and
(j) Press the stop button (25-C) of the
drive control (25) and continue with
switch (10) to the "EXT VOLTS"
tests in c below.
position, also, the safety clip (25-B)
w i l l remain off the stop button
Load (free running) Test.
Note. Test procedures below are utilized when the
(e) Place the starter test load disconnect
t e s t stand is not used as a source of power for oper-
switch (15) in the "ON" position
a t i n g the starter (cranking motor) when performing a
and turn the starter carbon rheo-
n o - l o a d ( f r e e - r u n n i n g ) t e s t , a above. Begin this test
stat (fig. 60) clockwise until ap-
with all cable harness and test leads removed from the
test stand and proceed as prescribed in (a) t h r o u g h (i)
proximately 23.8 volts are indicated
on the dc voltmeter (4). The current
(1) General. It is possible to provide dc
voltage power for no load (free run-
should be 20 amperes (table 9).
n i n g ) tests on starters (cranking
(f) Check the rpm of the starter (crank-
motors) through the means of a dc
ing motor) using the slide rule ta-
sembly of the test stand. Air for cool-
ing the generator must be supplied
1. Place the flange end of the slide rule
by an external blower.
o f the starter (cranking motor),
Note. Depending on the voltage and cur-
being careful not to resist the move-
r e n t rating of the starter (cranking motor)