28V DC and 400Hz Aircraft Ground Power Units

Q: What is a 28V DC / 400Hz combi static frequency converter used for?

A 28V DC / 400Hz combi static frequency converter is used to supply both regulated 28V DC power and 115/200V AC 400Hz power from a standard mains supply. It is commonly used for aircraft ground power, avionics testing, maintenance operations, and production line testing where both DC and AC aircraft power are required.

Q: Can the DC and AC outputs be used at the same time?

Yes. The combi static frequency converter is designed to provide simultaneous 28V DC and 400Hz AC outputs, allowing multiple aircraft systems or test equipment to be powered at the same time. This reduces the need for separate power units and improves operational efficiency.

Q: What input power supply does the converter require?

The unit accepts a standard 50Hz or 60Hz mains supply, depending on configuration. Input voltage and phase options can be specified to suit site requirements, including single-phase or three-phase supplies.

Q: Is the output suitable for sensitive avionics and test equipment?

Yes. The converter uses advanced IGBT-based solid-state inverter technology to deliver clean, low-distortion power with precise voltage and frequency control. This makes it suitable for sensitive avionics, aircraft electrical systems, and laboratory test environments.

Q: What protection features are included?

The system includes comprehensive built-in protection such as overload protection, short-circuit protection, over-voltage protection, and over-temperature monitoring. These features help protect both the converter and connected equipment during operation.

Q: Is the converter available as a mobile or fixed unit?

The 28V DC / 400Hz combi static frequency converter is available in both fixed installation and mobile configurations. This makes it suitable for use in aircraft hangars, maintenance facilities, production areas, and flight line support where flexibility or portability is required.

Q: What are the advantages over rotary converters?

Compared to traditional rotary converters, the solid-state combi converter offers quieter operation, higher energy efficiency, reduced maintenance requirements, and improved reliability. Its compact design also saves valuable floor space in hangars and test areas.

PX Electronics 28V DC and 400Hz Aircraft Ground Power Units provide dual-output AC/DC aircraft power from a single solid-state system. Designed for aviation maintenance environments, these combination GPUs supply regulated 28V DC power and stable 400Hz AC output for aircraft servicing, avionics testing, MRO hangars and ground support operations.

Technical Highlights for Aircraft Ground Power:

Solid-state conversion
Static design with no rotating machinery, helping reduce mechanical maintenance compared with generator-based systems.

Three-phase mains input
Operates from a 50Hz or 60Hz three-phase supply for aircraft-standard ground power output.

Stable output performance
Maintains voltage and frequency stability under changing aircraft, avionics and maintenance loads.

Control and protection
Digital monitoring, system status display and built-in protection against overload, short circuit and over-temperature conditions.

Fixed or mobile options
Available in fixed, mobile or semi-mobile configurations to suit hangar, service bay or flight line requirements.

Click here for a sample specification

Typical Applications:

Aircraft maintenance hangars
MRO facilities
Military aviation support
Helicopter ground support
Avionics servicing
Aircraft production facilities
Airport ground operations

Configuration:

PXe 28V DC and 400Hz aircraft ground power units can be configured to provide combined AC and DC aircraft-standard power from a single solid-state system. Each unit is designed to supply a regulated 28V DC output alongside 115/200V AC at 400Hz, reducing the need for separate DC supplies and 400Hz ground power equipment.

Systems operate from a three-phase 50Hz or 60Hz mains input and can be specified based on the required aircraft load, output rating, installation format, and control method. Fixed, mobile, and semi-mobile configurations are available depending on the hangar layout, service location, or flight line support requirements.

The static solid-state design uses no rotating machinery, helping reduce mechanical maintenance compared with generator-based systems. High-efficiency conversion, low total harmonic distortion and stable voltage and frequency regulation support reliable operation under changing aircraft load conditions.

Digital control and monitoring provide clear system status and operating information during use. Built-in protection functions respond to abnormal conditions, including overload, short circuits, and overheating.

For aviation maintenance environments, the system can be configured to support aircraft servicing, avionics workshops, MRO hangars, production lines, LRU testing and defence aviation support where combined 28V DC and 400Hz AC ground power is required.

Popular Configurations:

We have a variety of models available, please see below for some popular configurations. Please note: customers may request alternative voltages and frequencies as required, below are examples only.

Model	Capacity	Current Rating	Input	Output	Dimensions	Weight
PXe-3310001.6T 3ph In/3ph Out/1ph Out	1.6kVA	Output 1 – 16A per phase @ 20.8V Output 2 – 5.2A @ 115V	380V (L-L) ±10% \| 50Hz \| 3 Phase +N	Output 1 – 20.8V (L-N)/36V (L-L) \| 3 Phase +N (1kVA) \| 1000Hz Output 2 – 115V \| Single Phase +N (0.6kVA) \| 1000Hz	430x600x700mm	64kg
PXe-3330014.5T 3ph In/3ph Out/3ph Out	10kVA & 4.5kVA	Output 1 – 28A per phase @ 115V Output 2 – 5.9A per phase @ 254V	440V (L-L) ±10% \| 60Hz \| 3 Phase	Output 1 -0/200V (L-L) 115V (L-N \| 3 Phase +N (10kVA) \| 400Hz Output 2 – 254V (L-N)/440V (L-L) \| 3 Phase +N (4.5kVA) \| 400Hz	600x530x1650mm	220kg

Model

Capacity

Current Rating

Input

Output

Dimensions

Weight

PXe-3310001.6T

3ph In/3ph Out/1ph Out

1.6kVA

Output 1 – 16A per phase @ 20.8V

Output 2 – 5.2A @ 115V

380V (L-L) ±10% | 50Hz | 3 Phase +N

Output 1 – 20.8V (L-N)/36V (L-L) | 3 Phase +N (1kVA) | 1000Hz

Output 2 – 115V | Single Phase +N (0.6kVA) | 1000Hz

430x600x700mm

64kg

PXe-3330014.5T

3ph In/3ph Out/3ph Out

10kVA & 4.5kVA

Output 1 – 28A per phase @ 115V

Output 2 – 5.9A per phase @ 254V

440V (L-L) ±10% | 60Hz | 3 Phase

Output 1 -0/200V (L-L) 115V (L-N | 3 Phase +N (10kVA) | 400Hz

Output 2 – 254V (L-N)/440V (L-L) | 3 Phase +N (4.5kVA) | 400Hz

600x530x1650mm

220kg

Technical Specification

Capacity
Single Phase Output	kVA Ratings: 0.5kVA, 1kVA, 3kVA, 5kVA, 10kVA, 15kVA, 20kVA, 30kVA, 50kVA, 60kVA, 75kVA, 100kVA, 150kVA, 200kVA
Three Phase Output Versions	kVA Ratings: 1kVA, 3kVA, 6kVA, 9kVA, 15kVA, 20kVA, 30kVA, 45kVA, 60kVA, 100kVA, 150kVA, 200kVA, 300kVA, 400kVA, 500kVA (Select One kVA)
Input
Single Phase (Select One Individual Voltage)	110Vac ±10%, 115Vac ±10%, 120Vac ±10% 127Vac ±10%, 220Vac ±10%, 230Vac ±10%
Three Phase (Select One Individual Voltage)	115-127 (L-N) / 200-220V (L-L) ±10%, 220-240 (L-N) / 380-415V (L-L) ±10%, 3 Phase 4 Wire 440V (L-L) ±10%, 480V (L-L) ±5%, 3 Phase 3 Wire
Frequency	50Hz/60Hz ±5%, 400Hz (Optional)
Power Factor	≥ 0.8 (standard type) ≥ 0.9 (optional type, 12 pulse)
Output
Single Phase (Select One Individual Voltage)	Fixed: 110V, 115V, 120V, 127V, 220V, 230V, 240V Adjustable: 0~150Vac / 0~300Vac
Three Phase (Select Two Individual Voltages)	Fixed: 115/200V (L-N/L-L), 120/208V (L-N/L-L), 127/220V (L-N/L-L), 220/380V (L-N/L-L), 230/400V (L-N/L-L), 240/415V (L-N/L-L), 254/440V (L-N/L-L), 277/480V (L-N/L-L), 3 Phase 4 Wire Adjustable: 0~260V (L-N) / 0~520V (L-L), 3 Phase 4 Wire
Frequency	Fixed: 50Hz, 60Hz, 100Hz, 200Hz, 45-200Hz (adjustable) Optional: 400Hz, 40Hz~500Hz (adjustable), 16.67Hz, 25Hz, 50Hz, 60Hz, 400-1000Hz
Voltage Accuracy	≤ ±1% FS (Full Scale)
Frequency Accuracy	≤ ±0.1% FS (Full Scale)
Total Harmonic Distortion	THD ≤ 3% @ linear load, pure sine wave output
Crest Factor (Pk/rms)	3:1
Overload	100% for continuous, 101-200% shut down in 200mS
Interface	None for standard units, RS232C/RS485/GPIB (Optional)
Protection	Over-current, overload, over-voltage, over-temp, short circuit, alarm and indicators
Enclosure IP Rating	IP22 (Standard), IP32, IP54 (Optional). Special enclosure options available
LED/LCD Display	Digital frequency meter Digital voltage meter Digital current meter Digital power/PF meter
Connectors	Hard-wire terminals, EN60309, MIL-STD, or client choice
Operating conditions
Temperature	Operation: -10℃~55℃ Ambient: -10℃~45℃
Noise	≤ 65dB at 1 meter EN 55022, IEC1000-4
Humidity	10~90% non-condensing
Cooling	Variable speed fan, filtered air intake in base, exhaust at rear
Altitude	≤ 1800m
Castors or Feet	0.5-3kVA have rubber feet and lifting handles, 4kVA+ have castors with front brakes. A/Vs or feet optional
CE	CE Marked
Reliability and Efficiency
Mean Time Between Failure (MTBF)	50,000Hrs
Mean Time To Restore (MTTR)	< 30 min
Overall Efficiency	≥ 85%
Standards
GB50054-95, GB 50150-1991, GB 50150-2006, GB 50171-1992, GB/T 16935.5-2008, GB/T16935.4-2011
EN IEC61000-3-2, EN 61000-3-3, EN55032, EN55035, MIL-STD-1399, MIL-STD 461, MIL-STD704, STANAG 1008
For more information and support, please feel free to contact us