(9) Continue to operate the generator (al-
ternator) under above conditions for
will not be necessary if the generator
about 15 minutes. Throughout the
(alternator) is direct-driven, however,
test the dc voltage reading on the dc
the reading will be taken from the
voltmeter (4) should be within the
upper scale on the tachometer indica-
range of 27.4 to 28 volts. The field dc
tor meter (3) for the tests below. If
ammeter (2) reading should be within
the generator (alternator) is pulley-
the range of 6 to 10 amperes.
(15) Start the varidrive assembly (3)
Note.
It may be necessary to adjust the
variable
load 0-25 0-12.5 ampere rheostat
above, and turn the speed control
( 1 9 ) to
maintain the 100-ampere load dur-
handle (24) until 6,000 rpm are re-
i n g the
test, (6) above.
(10) Decrease the speed of the varidrive
meter (3) and repeat test procedures
assembly to 1000 rpm on the tachom-
(4) and (6) above (leave the battery
eter indicator meter (3) by turning
s w i t c h (22) remain in the "ON"
the speed control handles (24) clock-
position).
wise. Turn off the 50-25 fixed load
(16) The dc ouput voltage should be within
switch (17-B) and adjust the variable
the range of 27.3 to 28.3 volts on the
load 0-25 0-12.5 ampere rheostat (19)
dc voltmeter (4), the field current
until approximately 50 amperes are
(input) should be in the range from
registered on the load ac ammeter
6 to not more than 10-ampere on the
(1).
field dc ammeter (2).
(11) The output voltage should be 27.7 plus
(17) Turn the speed control handle (24)
partially counterclockwise until the
(4). The field dc ammeter (2) should
varidrive assembly speed is reduced
register between 6 to 10 amperes and
-speed. Place the switches in table
the ac ammeter (5) should register
in positions indi-
a p p r o x i m a t e l y 46 amperes with a
cated in column
of the table. Stop
reading of approximately 24 volts on
the varidrive assembly by depressing
the ac voltmeter (6).
the stop button (25-C) on the drive
(12) Place the equalizers coil test switch
control (25).
(8, fig. 15) in the "ON" position mo-
N o t e . If test results are not obtained as
mentarily and note the drop-off of the
above, check the indicator knob on all rotary
Voltage drop-off should be between
s w i t c h e s under the meters (fig. 47) to be
sure the knob is secure on the shaft of the
1.5 to 3.0 volts.
s w i t c h , and pointing to the correct position
Note. After the drop-off voltage is taken
o n the switch dial. If this condition exists,
in (12) above, it will take between 2 and 3
place the knob and switch shaft in the cor-
rect position on the switch dial, and tighten
lator to recover and "kick-in" to register the
t h e set screw in the knob securely.
voltage and amperage readings on the meters
N o t e . The following instructions are for tests and
a d j u s t m e n t s using the test stand covered by this pub-
(13) Turn the speed control handle (24)
l i c a t i o n . For further information for tests and adjust-
partially counterclockwise until the
varidrive assembly speed is reduced
r e g u l a t o r refer to TM 9-7003 and TB 9-2300-206-15
when performing test procedures in e and f b e l o w .
-speed and stop the varidrive as-
e. Test Procedures for Individual Control
sembly by depressing the stop button
Units.
(21-C).
(1) General.
(a) This test is similar to the test in d
from the low speed driving head (5,
fig. 7) and mount it on the
high speed
above, except that the cover of the
g e n e r a t o r (alternator) regulator
driving head (4, fig. 7). Recalibration