ARMY TM 9-6115-464-34
AIR FORCE TO 35C2-3-445-2
NAVY NAVFAC P-8-624-34
(h)
(i)
NOTE
This step is not applicable to generator sets having governors that utilize a threaded
shaft and lock nut(s) or other mechanical means as a method of operator speed
adjustment.
Adjust the generator set frequency for the minimum attainable frequency. Read and record all
instrument readings.
NOTE
This step is not applicable to generator sets having governors that utilize a threaded
shaft and lock (nuts) or other operator speed alignment.
Repeat 4-16c (1) and 4-16c. (2) (a) through (f) for each frequency.
d. Results. The data sheet shall show the maximum and minimum frequencies attained at rated 109d, the
maximum and minimum attainable frequencies at no load and actuation of the protection devices (if applicable).
Compare these results with the requirements of table 4-1.
4-16. OVERSPEED PROTECTIVE DEVICE TEST
a. General. To assure that adequate protection is afforded the generator set against overspeeding, the
overspeed protective device must operate properly.
b. Apparatus. A frequency meter or tachometer as described and illustrated in MIL-HDBK–705, Methods
104.1 or 109.1 shall be required.
c. Procedure.
(1) Preparation for Test. Connect the frequency meter in accordance with the applicable figure of
MIL-HDBK-705, Method 205.1, Paragraph 205.1.9 or utilize the tachometer in accordance with the
manufacturer’s instructions. Electronic governor and throttle stops must be deactivated.
(2) Test.
(a) Start and operate the generator set at rated speed (frequency), rated voltage and no load.
(b) Slowly increase the engine speed until the overspeed protective device actuates. Record the speed
of the generator set at this point, and the malfunction indicator light indication.
CAUTION
Do not operate the set in excess of 125 percent of rated speed or as otherwise limited
the equipment.
(c) Attempt to start the set. Record if starting is achieved. If the set did not start, reset the overspeed
protective device.
(d) Compare the test results with requirement of table 4-1.
4-16
in the procurement document. Failure to observe this caution could result in damage to
