16-17. OVERSPEED PROTECTIVE DEVICE TEST.
General. Overspeeds will not be possible to
obtain due to limiting factors incorporated in the
fuel injection pump.
Overspeed Switch. Perform a bench test on the
overspeed switch to check the proper trip points.
Functional Check. Perform a function check of
16-18. CIRCUIT INTERRUPTER TEST (Short Circuit).
General. A circuit interrupter is connected
between the generator voltage reconnection
system and the generator set output terminals to
disconnect the generator output from the load
and also to protect the generator from a short
circuit. The circuit interrupter is operated from a
current sensor external to the interrupter.
Apparatus. Instrumentation for measuring load
conditions shall be as described and illustrated
in MIL-HDBK-705. In addition, a noninductive
shunt; a short-circuiting switch; a galvanometer
matching networks; as oscillograph as described
and illustrated in MIL-HDBK-705, Method 106.1,
paragraph 106.1.3; and galvanometers having a
flat frequency response (flat within plus or minus
five percent) from DC to 3,000 Hz will be
Preparation for the test.
instrumentation in accordance with
the applicable figure of MIL-HDBK-
205.1.10 for one for one voltage
Connect the shunt, galvanometer
matching network, oscillograph, and
short-circuiting switch as illustrated
in figure 512.1.1.
Start and operate the generator set
at rated voltage, rated frequency
and rated load.
Set the oscillograph time marker to
a minimum of 0.01 seconds or use
a 60 Hz timing trace set the chart
speed such that the individual peaks
of the current waveform are clearly
visible and adjust the peak-to-peak
approximately 12 millimeters).
Prior to closing the short-circuiting
switch, record a portion of the
steady state load for calibration.
With the same load conditions
record all instrument readings.
With oscillograph still recording the
steady state current, close the short-
If the circuit interrupter fails to
operate within the specified time,
prevent damage. Note the failure
to operate on the data sheet.
The generator set contains a short-
circuit malfunction indicator, check
and, record its indication.
Repeat steps (a) through (e) above
condition (L1-L0,L2-L3, L1-L2-L3 etc.)
Repeat steps (a) through (f) above