p e r e positions open circuit), 3-pole, 2-deck,
scribed in paragraph 18. They are used when
rotary-type selector switch. It is used to place
calibrating the dc voltmeter. With the dc volt-
the load dc ammeter (1) in series with the dc
meter circuit selector switch (23) set in a posi-
systems undergoing test, within ranges of 50,
tion between any of the selection points and the
150, and 500 dc amperes, by setting the
dc voltmeter range selector switch (22) set in
s w i t c h in the "50A (X1)," "100A (X3)," and
one o f t h e v o l t a g e p o s i t i o n s ( 1 0 V ( X 1 ) ,
"500A (X10)" positions (par. 11).
20V (X2), or 50V (X5)), the meter can be cali-
brated by applying the same amount of dc volt-
age which was selected on the switch (22) to
(Designated as LOAD DC AMMETER
the calibrating binding posts. A correctly cali-
STARTER TEST)
b r a t e d meter will indicate the amount of ap-
The load dc ammeter starter test selector
plied dc voltage.
switch (16), located directly under the load dc
ammeter (1) near the left hand end of the main
control panel, is a 5-position (position between
The ac ammeter calibrating jack (13), lo-
marked positions open circuit) 3-pole, 2-deck,
c a t e d directly under the ac ammeter (6) near
rotary type selector switch. It is used to place
the right hand end of the meter panel, is a plug-
the load dc ammeter (1) in series with the cir-
in type unit and is used when calibrating the
c u i t of the starter system undergoing test to
ac ammeter. The ac ammeter can be calibrated
i n d i c a t e current draw (par. 11). The switch
while in use by connecting an external accurate
is set in the "FREE-RUN" (X4) position when
ac ammeter in series with it, using the calibrat-
p e r f o r m i n g no load (free running) tests on
ing jack, and the readings on both meters should
starters (cranking motor) and set in the
coincide, The external meter must have a move-
" S T A L L TORQUE (X20)" position when per-
ment of 0-5 ac amperes and be capable of being
f o r m i n g stall torque tests on starters. The
used throughout the frequency range of 70 to
switch is placed in the off position when not
800 cps (cycles per second).
being used for the above two tests.
The ac voltmeter calibrating binding posts
(Designated as FIELD DC AMMETER
( 1 4 ) , located directly under the ac voltmeter
RANGE SELECTOR)
(7) on the right hand end of the meter panel,
The field dc ammeter range selector switch
are a threaded two-piece post as described in
( 1 7 ) , located directly under the field dc am-
meter (2) near the left hand end of the main
the ac voltmeter. With the ac voltmeter phase
control panel, is a 5-position (position between
selector switch (27) set between "T1-T2" and
marked ampere positions open circuit) 2-pole,
" T 1 - T 3 " positions or between "T1-T3" and
1 deck, rotary type selector switch. It is used
"T2-T3" positions, and the ac voltmeter range
to place the field dc ammeter (2) in series with
selector switch
(26)
set
in
either
the
t h e field circuit of the dc system undergoing
"25V (X1)" or "50V (X2)" position, the meter
test, within ranges of 5, 15, and 30 dc amperes,
can be checked for correct calibration by con-
by setting the switch in the "5A (X1),"
necting the same amount of ac voltage which
" 1 5 A (X3)," and " 3 0 A (X6)" positions (par.
was selected on the switch (26) to the calibrat-
12).
ing binding posts. A correctly calibrated meter
will indicate the amount of applied ac voltage.
(Designated as TACHOMETER lNDlCA-
TOR HI-LO)
(Designated as LOAD DC AMMETER
The tachometer indicator high-low switch
RANGE SELECTOR)
(18), located directly under the tachometer in-
The dc ammeter range selector switch (15),
dicator meter (3) near the left hand center of
located directly under the load dc ammeter (1),
the main control panel, is a 3-position (center
on the left hand end of the main control panel,
p o s i t i o n open circuit), 1-pole, 1-deck, rotary
i s a 5-position (position between marked am-
type selector switch. It is used in conjunction
