Aircraft 400Hz + 28Vdc Avionics Ground Power Units

Q: What is a 28V DC / 400Hz ground Power Unit (GPU) used for?

A 28V DC/400Hz ground Power unit (GPU) supplies 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 Ground Power Unit (GPU) is designed to provide simultaneous 28V DC and 400Hz AC outputs, enabling multiple aircraft systems or test equipment to be powered simultaneously. 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 GPU 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 GPU available as a mobile or fixed unit?

The 28V DC/400Hz Ground Power Unit (GPU) is available in both fixed 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?

A Ground Power Unit uses solid-state power electronics and is much lighter and more compact than rotating machinery. The GPU provides greater control over output voltage and frequency, as well as precise control of V and A protection. Unlike rotary machines, there are no mechanical maintenance requirements

Q: How do Ground Power units (GPU) fault diagnostic systems work?

Ground Power Units (GPU) fault diagnostic systems work by monitoring voltage, current, and power, as well as phase loss. These errors are written to Non-Volatile RAM (NVRAM). SIL Watch-dog options are available for independent monitoring and reporting.

Q: What is a GPU Watch-Dog System used for?

Watch-dog or independent fault-monitoring systems are available to monitor and report the health of Ground Power Units, particularly high-kVA units. These autonomous fault-diagnostic systems monitor voltage, current, power, and phase loss. These errors are written to Non-Volatile RAM (NVRAM) and can be sent via Networks and SMS.

PXe-330000-400F-DC Series

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

Technical Highlights for PXe-330000-400F-DC Series Aircraft Ground Power:

Solid-state conversion
Static converter design with no rotating machinery, rugged high reliability reducing running cost 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 component loads

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

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

Click here for a sample specification

Typical PXe-330000-400F-DC Applications:

Aircraft maintenance hangars
MRO facilities
Military aviation support
Avionics servicing
Avionic product development
Supports GA and commercial power requirements

PXe-330000-400F-DC Configuration:

Series PXe-330000-400F-DC provide protected 115V 400Hz and 28Vdc aircraft ground power, configured to provide 400Hz AC or AC and DC combination 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-331006-400F-DC 3ph Input Out 1 – 3ph Out 2- DC	5kVA 1kVA	Output 1 – 14.5A per phase @ 208VL-L / 115VL-N Output 2 – 35A @ 28Vdc	380V (L-L) ±10% \| 50Hz \| 3 Phase +N (applies to both o/ps)	Output 1 – 208VL-L 115VL-N 3 Phase +N (5kVA) \| 400Hz Output 2 – 28Vdc (1kVA) \| DC	430x600x700mm	64kg
PXe-333014.5-400F-DC 3ph Input Out 1 – 3ph Out 2 – DC	10kVA & 4.5kVA DC	Output 1 – 29A per phase @ 115VL-N Output 2 – 16A @ 270Vdc	440V (L-L) ±10% \| 60Hz \| 3 Phase	Output 1 0-208V (L-L) 0-115V (L-N \| 3 Phase +N (10kVA) \| 400Hz Output 2 – 270Vdc \| DC	600x530x1650mm	220kg

Model

Capacity

Current Rating

Input

Output

Dimensions

Weight

PXe-331006-400F-DC

3ph Input
Out 1 – 3ph
Out 2- DC

5kVA
1kVA

Output 1 – 14.5A per phase @ 208VL-L / 115VL-N

Output 2 – 35A @ 28Vdc

380V (L-L) ±10% | 50Hz | 3 Phase +N (applies to both o/ps)

Output 1 – 208VL-L 115VL-N 3 Phase +N (5kVA) | 400Hz

Output 2 – 28Vdc (1kVA) | DC

430x600x700mm

64kg

PXe-333014.5-400F-DC

3ph Input
Out 1 – 3ph Out 2 – DC

10kVA & 4.5kVA DC

Output 1 – 29A per phase @ 115VL-N

Output 2 – 16A @ 270Vdc

440V (L-L) ±10% | 60Hz | 3 Phase

Output 1 0-208V (L-L) 0-115V (L-N | 3 Phase +N (10kVA) | 400Hz

Output 2 – 270Vdc | DC

600x530x1650mm

220kg

Order Codes:

A product order code can be derived from the main ordering information using the structure below:

Generic order code is based on this format: PXe-330000-400F-DC and all PXE order codes start with the six digits like 330075 in this case indicating 3ph-input 3ph-output and 75kVA

For example a 3 phase in 50Hz, 3 phase out, 100kVA, 400Hz unit with 28Vdc = PXE-330100-440F-DC

PXE-330100-400F-DC-[INPUT]-[OUTPUT1]-[OUTPUT2]-[RATING]-[ENCLOSURE]-[CONTROL]

PXE-330100-400F-DC-[3P400V50]-[3P200V400]-[28VDC]-[100KVA]-[IP22]-[RS485]

This would represent:

(PXE-330100-400F-DC) – PX Electronics Ground Power Unit 100kVA
(3P400V50) – 3 phase, 400VL-L, 50Hz input
(3P200V400) – 3 phase, 200VL-L, 400Hz output 1
(28VDC) – 28Vdc output 2
(100KVA) – 100kVA rating
(IP22) – IP22 enclosure
(RS485) – Control

For a manually controlled standard enclosure version, the part number may look like this:

PXe-330100-400F-DC-3P400V50-3P200V400-28VDC-100KVA-IP22-MC

Model	Input	Output	Capacity	Enclosure	Interface Options
PXe-330000-F-C PX Electronics – Ground Power Unit	3P400V50 3P = Three Phase 400VL-L = Input Voltage 50 = 50Hz Frequency	3P200V400 3P = Three Phase 200VL-L = Input Voltage 400 = 400Hz Frequency 28VDC – Output 2	100KVA 100kVA capacity	IP22 Standard commercial IP22 enclosure	MC Manual Control Interface

Model

Input

Output

Capacity

Enclosure

Interface Options

PXe-330000-F-C

PX Electronics – Ground Power Unit

3P400V50

3P = Three Phase
400VL-L = Input Voltage
50 = 50Hz Frequency

3P200V400

3P = Three Phase
200VL-L = Input Voltage
400 = 400Hz Frequency

28VDC – Output 2

100KVA

100kVA capacity

IP22

Standard commercial IP22 enclosure

Manual Control Interface

Available Options:

IP54-rated enclosure
Rugged enclosure option for outdoor, industrial, marine or aviation-related environments where additional protection is required against humidity, condensation, salt spray, water ingress and dust.

Conformal coating
Additional coating of internal PCBs and selected electronic components to improve protection in harsh, humid or corrosive environments.

19-inch rack mount construction
Available on smaller models where the AC power supply needs to be integrated into an existing rack, cabinet, laboratory bench system or production test area.

Remote watchdog monitoring
Typically offered on models above 50kVA. The watchdog system can provide real-time fault notification via SMS, data history logging, remote operation, and automatic restart functionality, subject to application and site requirements.

Cables and terminations
Input and output cable assemblies, connectors, and termination arrangements can be supplied to suit installation, load connection, and site operating requirements.

Mobile base and handling options
Wheeled bases, rubber castors, and swivel tow bars are available when the AC power supply needs to be moved between test areas, production lines, service bays, or operating locations. This option is suitable for facilities where flexible positioning and practical handling are important.

PXe-330000-400F-DC Series Technical Specification

Capacity
Single Phase Output (Other options available on request)	kVA Ratings: 0.5kVA, 1kVA, 3kVA, 5kVA, 10kVA, 15kVA, 20kVA, 30kVA, 50kVA, 60kVA, 75kVA, 100kVA, 150kVA, 200kVA
Three Phase Output (Other options available on request)	kVA Ratings: 1kVA, 3kVA, 6kVA, 9kVA, 15kVA, 20kVA, 30kVA, 45kVA, 60kVA, 100kVA, 150kVA, 200kVA, 300kVA, 400kVA, 500kVA
Input
Single Phase (Select One Individual Voltage)	110Vac ±10%, 115Vac ±10%, 120Vac ±10% 127Vac ±10%, 220Vac ±10%, 230Vac ±10%, 400V ±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%, 440V (L-L) ±10%, 480V (L-L) ±10%, 690V (L-L) ±10%, 3 Phase 3 Wire or 3 Phase 4 Wire
Frequency	50Hz/60Hz ±5%, 400Hz (Optional)
Power Factor	≥ 0.8 (standard type) ≥ 0.9 (optional type, 12 or 18 pulse)
Output
Single Phase (Select One Individual Voltage)	Fixed: 110V, 115V, 120V, 127V, 220V, 230V, 240V, 400V, 28Vdc Adjustable: 0~150Vac/0~300Vac 28Vdc
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), 400/690V (L-N/L-L), 3 Phase 3 Wire or 3 Phase 4 Wire Adjustable: 0~260Vac/0~520Vac, 3 Phase 3 Wire or 3 Phase 4 Wire 28Vdc
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