TM
9-4910-663-12
(6) Vary SPEED CONTROL (fig 2-4) to obtain the desired speed as
indicated by TACHOMETER RPM meter (M1, fig 2-1). Counterclockwise
rotation of the SPEED CONTROL (fig 2-4) increases speed and clockwise
rotation decreases speed.
(7) To stop the varidrive, set SPEED CONTROL (fig 2-4) fully
clockwise to minimum speed and press STOP pushbutton switch (S2, fig
(8) Open the high voltage compartment door and position circuit
breaker switch (CB1, fig 2-5) to the OFF position.
NOTE
If varidrive is not to be used often and is to be
idle for a week or so, position SPEED CONTROL
(fig 2-4) to mid speed range before stopping. This
will preclude a varidrive belt set at a small ra-
dius which will give a thumping sound when started
again until the belt becomes flexible.
b. Operating TACHOMETER RPM Meter. The tachometer indicator cir-
cuitry is so designed that the speed of the generator being tested,
whether it be direct driven or pulley driven, is indicated on TACH-
OMETER RPM meter (M1, fig 2-1).
(1) Direct Drive Generators.
DIRECT DRIVE position.
(b) TACHOMETER RPM meter (M1, fig 2-1) will now indicate
directly the speed of both output shafts.
1. The low speed output shaft (1, fig 1-2), right side
facing drive take-off, will indicate on the 0-5100 RPM range.
2. The high speed output shaft (3, fig 1-2), left side
facing drive take-off, will indicate on the 0-12000 RPM range.
(2) Pulley Driven Generators - When testing pulley-driven gener-
ators, it will be necessary to establish a speed for the generator and
adjust the tachometer indicator to indicate this speed. After com-
pleting this adjustment, any variation in the speed of the pulley-
driven generator will be indicated on the tachometer indicator. To
make this adjustment properly, proceed as follows:
(a) Mount the generator to be tested on the varidrive (fig 2-9
and 2-10).
(b) Turn TACHOMETER RPM SELECT switch (S36, fig 2-1) to the
DIRECT DRIVE position.
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