New Industry Products

Military-Grade 4kW/5kV 3-Phase to Single-Phase AC Changer

June 04, 2019 by Scott McMahan

SynQor, Inc. announced the MAC-4000, a compact, military-grade 3-phase to single-phase ac changer. It has a shock-proof and weather-proof construction and offers true isolation between the input and output.

The company designed this 4kW/5kVac Phase/Frequency ac changer for the extreme environmental and demanding electrical conditions of military/aerospace applications.

The 1U-sized rack unit weighs 33lbs. The MAC-4000 incorporates the company's field-proven, high-efficiency designs, and rugged packaging technologies. It accepts a 3-phase 440Vrms ac input and converts it to a well-conditioned single-phase ac output using a two-stage isolated dc mid-bus topology.

Options include a selection of output voltage (115Vrms or 230Vrms), output frequency (50Hz, 60Hz or 400Hz) and an electronic circuit breaker on the ac output that allows glitch-free, fault-tolerant parallel operation of up to 32 units in single-phase, 3-phase, and split-phase configurations as well as (N+M) redundancy.

An optional floating output ground optional feature makes it suitable for air or sea crafts MIL-STD-1399-300B compliant applications that might require that feature.

Also, MAC-4000 can be equipped with an Ethernet-SNMP optional module that allows real-time remote system monitoring with trap/email.

In addition to aiding the change of ac output characteristics from an established ac input source, the MAC-4000 tackles the problem of unbalance loads on 3-phase systems in aircraft and ships. The MIL-STD-1399-300B requires the balancing of all phase currents to within ±5% for ships and ±3% for submarines. SynQor contends that achieving this high degree of the phase current balance with today's single-phase electronic loads is now easy its new ac changer.

The 3-phase MAC-4000 lets single-phase loads appear at the power source as clean, well behaved, nearly zero reactance balanced, and MIL STD 1399-300B compliant 3-phase load.

SynQor says the unique MAC-4000 product outperforms other industry solutions in terms of output power, efficiency, reliability, flexibility, low weight, and small size.


  • 4,000W (5,000Vac) output power
  • Two-stage, isolated dc mid-bus topology
  • Balanced load currents for 3-Phase sources; MIL STD 1399-300B
  • 3-Phase 360-528 Vrms L-L 3-wire input 50 or 60 Hz
  • 115Vrms or 230Vrms ac output at 50Hz, 60Hz, or 400Hz
  • Full power operation: -40°C to +55°C
  • Up to 32 units can be combined to form a higher power fault-tolerant, glitch-free system, which can also have N+M redundancy
  • Battle Mode for over-temperature events
  • 1U high rack mount unit (17.00in W x 22.42in D x 1.73in H)
  • Low weight: 33 lbs

Specification Compliance

  • MIL-STD-1399-300B
  • MIL-STD-810G
  • MIL-STD-461F