Note
Rated speed (100 percent engine speed) is defined as
4200 rpm indication on the tachometer generator. This
corresponds to 6000 rpm of the reduction drive output
and 56, 000 rpm of the turbine.
a.
Speed Adjustment. After the APU attains 100 percent rated speed at no load,
adjust acceleration control to obtain 102 percent engine speed for Model
T-62T-2, and 105 percent for Model.T-62T-2A. When these speeds have been
obtained for the APU on the check stand, run the APU for approximately 10
minutes and carefully check for fuel and oil leaks.
Note
Engine should shut down when rated speed is exceeded
by 10 percent. The ENGINE SPEED indicator registers
in percent. The small hand makes one revolution for
each 10 percent through 100 percent. Each one percent
is indicated by the small hand after 100 percent is
exceeded.
Thermal Protective Device. If the APU exceeds the temperature limits of
b.
1070F (576.5C) for Model T-62T-2, and 1090F (587.7C) for Model
T-62T-2A, the APU automatically shuts down.
Low Oil Pressure Switch. The low oil pressure switch is set to shut down
C.
the APU if decreasing oil pressure reaches 6 1 psig.
3-14. AC POWER OPERATION.
3-15. The mobile check stand may be used to furnish 400-cycle, 115/200-volt, ac
power for the aircraft preflight operations, or other needs. A 50-foot power cable is
provided with the check stand, and is equipped with a connector to engage the ac power
input receptacle on the aircraft.
CAUTION
To preclude damage to electrical components, always
monitor check stand controls during ac generator opera-
tion to avoid operation at low frequency, high frequency,
or low voltage. Avoid contact with high-voltage compo-
nents in the control console during operation of the ac
generator,
3-11
