(7) Check to see if the toggle switch on the
12) in
the opposite position. (par.
position, then slide the safety clip
Warning: Before reaching into the
(21-B) off the stop button (21-C) and
high voltage compartment to change
depress the start button (21-A) (do
the position of the drive reversing
not hold the start button depressed
switch, place the toggle switch on the
more than 10 seconds) to start the
position, as high voltage exists in the
varidrive assembly. Check for correct
surrounding area of this compart-
rotation of the generator pulley (par.
ment.
d. Test Procedures. The procedures for this
(8) If it is necessary to change the rotation
of the generator (correct rotation is
except the ampere load applied with the
important, otherwise, the generator
fixed load switches (12-A), (12-B), (12-C),
will have no output), stop the vari-
(12-D) and the variable load 0-25 0-12.5 am-
drive assembly by pushing the stop
pere rheostat (13) may have to be varied to
button (21-C), let the varidrive as-
sembly come to a complete stop, and
place the drive reversing switch (fig.
other models of generator control boxes.
Note. The key numbers shown below in
parentheses in
this section refer to
figure 32 except where otherwise
indicated.
Section IX. TESTING JACK AND HEINTZ 300-AMPERE GENERATOR
Model and ordnance
number
G22-2 (ORD 8717421)
The Jack and Heintz 300-ampere generator
Model and ordnance
number
G22-7F (ORD 10889998)
Federal stock number
grounded field, consisting of interpole and com-
model (G22-7F) 2920-830-1293
pensating windings. It is direct driven in a
6
Poles
counterclockwise rotation at the drive end
Brushes
6
(turns to the left facing pulley (fig. 42). The
2,000 to 6,500 rpm
Speed range
models G22 and G22-2 have a built-in cooling
94 pounds (model G22 and
Weight
fan whereas the model G22-7F has a cooling
G22-2)
blower which is mounted separately on the
housing of the generator. Refer to TM 9-
105 pounds w/o blower
Weight
2920-224-35.
(model G-22-7F)
Type windings
Interpole and compen-
126. 300Ampere Generator Performance
sating
Test (Jack and Heintz)
Field connections
To negative brush
Rotation direction
a. Purpose. This test is performed to deter-
Counterclockwise
(drive end)
mine whether the generator is functioning in
accordance with the manufacturer's specifica-
30 volts
Rated voltage
tions for ampere and voltage output when op-
Rated amperes
300 amperes
erating under normal conditions.
nonwaterproof
Type housing
16 tooth
Spline drive
b. Tabulated Data.
Manufacturer
Brush length
new 1-3/16 inch-worn
Jack and Heintz
minimum 11/16 inch
Model and ordnance
Field ground
internal
G22 (ORD 7358630)
number