Testing military ground & shipboard to MIL-STD-704F
An aircraft bus is not a clean supply, and MIL-STD-704F is the document that says exactly how unclean it is allowed to get. You are testing vehicle electronics, shipboard converters, deployable power systems on 28 VDC, 270 VDC, 440 V 60 Hz shipboard, proving survivability on a bus shared with motors, weapons and generators. The standard turns on 400 Hz and voltage transients; it says nothing about harmonic immunity sweeps or humidity/bias reliability, which belong to a different qualification entirely. Reproducing it takes 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.
What you are testing
- Device under test
- vehicle electronics, shipboard converters, deployable power systems
- Bus
- 28 VDC, 270 VDC, 440 V 60 Hz shipboard
- Who buys this
- defence primes and depot sustainment programmes
What MIL-STD-704F does not cover
- harmonic immunity sweeps
- humidity/bias reliability
- grid ride-through
If your programme needs those, they come from a different standard and often different hardware.
The limits this test has to reproduce
Ground and shipboard platforms live on the DC side of this standard. The 400 Hz AC clauses are not your test — the 28 V and 270 V bus behaviour is.
| Parameter | Value | Clause |
|---|---|---|
| 28 VDC steady state | 22.0–29.0 V, ripple ≤1.5 V | Table IV |
| 28 VDC transient | 50 V for 12.5 ms; sag 18 V for 15 ms | Figure 13 |
| 270 VDC steady state | 250.0–280.0 V, ripple ≤6.0 V | Table IV |
| 270 VDC transient | 330 V for 20 ms; sag 200 V for 10 ms | Figure 16 |
| Emergency 28 V | 16–29 V | §5.3.2.3 |
| Electric starting | 12–29 V | §5.3.2.4 |
| 28 VDC abnormal | V = 31.38 + 0.931/t; 31.5 V sustained (under 20.0 V) | Figure 14 |
The clauses military programmes actually face, as published in MIL-STD-704F, revision F, 12 March 2004. See every limit in MIL-STD-704F. Certification work should be run against the published standard.
What decides the rig here
The requirements that separate a system that can run this programme from one that only meets the headline numbers.
No 400 Hz means no aircraft source
Buying an aviation-grade AC source for a ground platform is a common and expensive mis-spec. The DC clauses are the requirement.
Engine-start droop is the hard case
A slow ramp from deep undervoltage exercises hold-up behaviour that a step transient never reaches.
Depot sustainment outlives the instrument
Programmes running 20+ years should confirm calibration and support horizons before standardising a rack.
Equipment that covers it
Other standards this DUT usually faces
Further reading on MIL-STD-704F
- 28 VDC Aircraft Bus Testing: The Second Programme Inside MIL-STD-704F
- CAGE, UEI and NAICS: What a Prime's Supplier-Vetting Search Actually Resolves
- DFARS 252.204-7012 for Test-Equipment Suppliers: The 72-Hour Report and the Media You Must Not Wipe
- DO-160 vs MIL-STD-704: Where Civil and Military Aircraft Power Standards Split
- MIL-STD-1399 Testing: Your Contract May Cite a Cancelled Revision
- Sizing a 400 Hz Source for Inrush: kVA Is the Last Number to Pick
- Specifying Test Equipment in a Federal Contract: Name the Method, Freeze the Revision, Agree What Pass Means
- Solid-State 400 Hz Sources vs Motor-Generator Sets: What Actually Changes
- 400 Hz AC Source Buyer's Checklist: Sizing for Inrush, Crest Factor and Nonlinear Loads
- MIL-STD-704F for Test Engineers: The Conditions Your AC Source Must Actually Reproduce
Send us the clauses you have to satisfy
We will come back with the source and load capability that covers them — and tell you plainly if something in your spec needs hardware we would not supply.
Talk to an engineer