MIL-DTL-6162C
4.6.15 Consecutive start cycle. The starter generator shall be operated for five consecutive start cycles at the
beginning and at the end of the 1200-cycle starter endurance test (see 4.6.18.1.1). Each cycle shall be the same as
that specified for the endurance test, except that the off time between cycles shall be one minute and no external
cooling shall be permitted other than that afforded by internal fans. Upon completion of the consecutive start cycle
test the machine shall be operated at the specified minimum rated speed and the residual voltage measured without
any form of shunt field excitation, field flashing or prior generator operation. The residual voltage shall not be less
than 0.8 volts.
4.6.16 Overload. Once every two hours during the endurance test specified in paragraph 4.6.18.2, the load
shall be increased to 150 percent of rated load for a period of two minutes. After one minute of cooling at no load,
the test shall be repeated at 200 percent of rated load for five seconds. A cooling period of one minute at no load
may follow the 200 percent load application (see 4.6.22.1). During the overloads, the regulated voltage shall not be
less than 26 volts. During the 150 percent load, commutator sparking shall not exceed the number 2 requirement of
Figure 5. During the 200 percent load, commutator sparking shall not damage the commutator or degrade
subsequent performance.
4.6.17 Voltage regulator compatibility. The machine shall be operated with approved voltage regulators
conforming to MIL-R-23761 or as designated by the associated specification sheet. The machine shall be properly
connected to be controlled by the specified voltage regulator. The total resistance of the field circuit leads shall be
0.1 ± 0.01 ohms. The total feeder resistance (positive and negative) shall be adjusted to provide a 1.9 ± 0.1 volt
feeder voltage drop after temperature stabilization at rated load current and standard sea level conditions. The
voltage sensing leads shall carry no current other than that required by the voltage regulator sensing circuit.
4.6.17.1 Voltage regulation (single generator). The voltage regulation shall be observed over the rated
generator speed range from no load to rated load current. The regulated voltage shall comply with the fixed ambient
temperature voltage regulation requirements as specified on the associated specification sheet for the voltage
regulator. Voltage transients due to switching up to 200 percent rated current shall not exceed the limits of
MIL-STD-704, and shall recover and remain within the steady state limits with no more than one overshoot. No
sustained oscillations shall occur.
4.6.17.2 Parallel operation. Two or more generators shall be connected as specified for parallel operation.
Load division over the generator rated speed range shall remain within 10 percent of the generator rated current
from 25 percent to full rated load current. Load shifting among generators operating in parallel shall not produce a
peak-to-peak load variation about the average load current of any machine greater than 10 percent of the generator
rated current.
4.6.18 Endurance. The machine shall successfully complete the applicable endurance tests below.
4.6.18.1 Starter. The starter generator shall be subjected to a 1200 cycle endurance test. Each cycle shall
consist of three phases of operation as follows:
a. Phase A - This phase shall consist of accelerating the specified flywheel inertia load from rest to the
specified speed within the specified time and with the input current limited to the specified value as indicated on the
associated specification sheet.
b. Phase B - This phase shall consist of a 10-second period of steady state operation at the specified load
and terminal voltage.
c. Phase C - After completing Phase B, the torque load shall be removed and the starter permitted to
accelerate the flywheel inertia load to the specified speed within the specified time. Off time between cycles shall be
as specified.
Note: The acceleration specified for Phases A and C assumed a frictionless system and does not consider test stand
losses such as windage or bearing friction. Accordingly, in order to ensure that the minimum drive speed specified
in Phase C is attained, an external assist torque may be supplied or the flywheel inertia load may be reduced. In
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