Intepro Systems

MIL-STD-704F

MIL-STD-704F Aircraft Electric Power Testing

Revision F, 12 March 2004

Programmable AC source to ≥180 V RMS L-N (≥271.8 V peak), 3-phase, 360–800 Hz plus 60 Hz, with phase-angle control and millisecond-resolution voltage/frequency envelope sequencing. DC sources to ≥50 V (28 V bus) and ≥350 V (270 V bus) with ripple injection.

This standard turns on

  • 400 Hz
  • voltage transients
  • abnormal conditions
  • emergency and starting modes

And says nothing about

  • harmonic immunity sweeps
  • humidity/bias reliability
  • grid ride-through

Cited limits

Every value carries the clause, table or figure it comes from.

ParameterValueClause
Steady-state voltage (400 Hz AC, L-N)108.0–118.0 V RMSTable I
Frequency393–407 Hz, modulation 4 HzTable I
Distortion factor≤0.05Table I
Crest factor1.31–1.51Table I
Peak voltage±271.8 VTable I
Normal AC transientsurge 180 V for 10 ms; sag 80 V for 10 msFigure 3
Abnormal AC overvoltageV = 124.6 + 2.77/t for 0.05 ≤ t ≤ 6.925 sFigure 4
28 VDC steady state22.0–29.0 V, ripple ≤1.5 VTable IV
28 VDC transient50 V for 12.5 ms; sag 18 V for 15 msFigure 13
270 VDC steady state250.0–280.0 V, ripple ≤6.0 VTable IV
270 VDC transient330 V for 20 ms; sag 200 V for 10 msFigure 16
Emergency 28 V16–29 V§5.3.2.3
Electric starting12–29 V§5.3.2.4
Abnormal AC sustained125 V sustained (undervoltage mirror 100 V)Figure 4
Frequency rate of change250 Hz/s normal, 500 Hz/s abnormalTable II
28 VDC abnormalV = 31.38 + 0.931/t; 31.5 V sustained (under 20.0 V)Figure 14

Equipment for this standard

Further reading

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