MIL-DTL-3124E(SH)
3.4.22 Dynamic balance. The generator rotor shall be balanced dynamically by one of the following methods
so that, at rated speed of the rotor, the remaining unbalanced centrifugal force shall not exceed the limits in
accordance with Type II of MIL-STD-167-1 (see 4.6.6):
a.
Balance weights attached by securely locked, noncorrodible bolts.
b.
Balance weights dovetailed and anchored in balancing grooves.
c.
Drilling out material or use of various lengths of threaded studs.
d.
Securely welded balance weights.
3.4.23 Dielectric strength. The generators shall withstand a dielectric strength test of twice the normal voltage
of the circuit, plus 1,000 volts (see 4.6.11).
3.4.24 Electromagnetic interference (EMI). EMI for the generator and associated control equipment
(see 4.6.29) shall be in accordance with the following requirements in accordance with MIL-STD-461:
a.
CE01
b.
CE03
c.
CS01
d.
CS02
e.
CS06
f.
RE01
g.
RE02
h.
RS03
i.
UM05
3.4.25 Overspeed. Generators shall withstand an overspeed of 25 percent (see 4.6.9), and not greater than
5,000 overspeed operations of 15 percent.
3.4.26 Transient-subtransient reactance. The transient reactance shall not exceed 20 percent. The range of
subtransient reactance shall be between 13 and 16 percent.
3.4.27 Electrical insulation. A sample coil or winding (see 3.3.25.1) shall be provided (see 6.2), which shall
have interstices filled in and be free of air and water (see 4.6.1).
3.4.28 Calculations. The voltage dip shall be determined at the generator switchboard, and at the terminals of
an induction motor having the characteristics given below when it is started, with the generator carrying an initial
load of the magnitude specified below. The voltage dip at the generator switchboard shall not exceed 14 percent
rated voltage, and the voltage dip at the motor terminals shall not exceed 16 percent.
a.
Motor characteristics:
(1) Rated voltage: 450 volts
(2) Locked-rotor current: I = 0.67 per-unit
(3) Locked-rotor power factor: 0.25 p.f.
(4) Full-load power requirements: 0.20 per-unit at rated power factor
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