What is the Most Common Ground Power Unit?

400Hz frequency converter - the most popular aircraft ground power unitThe most common type of Ground Power Unit (GPU) used in aviation and other industries is the 400 Hz AC (Alternating Current) GPU. This kind of GPU is frequently utilised to give aeroplanes on the ground electrical power so they may operate their systems and complete maintenance procedures without relying on their onboard engines or APUs.

These 400Hz frequency converters are specialised devices used in aviation to convert the electrical frequency of the power supply to a frequency compatible with the aircraft’s systems. They play a crucial role in providing the appropriate electrical power to aircraft while on the ground.

Here are just a few of the benefits that they provide:


  1. Electrical Frequency Difference: Different regions and countries around the world may have varying standards for electrical power distribution, including the frequency of the alternating current (AC) electricity supplied to buildings and infrastructure. The standard frequency for AC power can be either 50 Hz or 60 Hz, depending on the location.
  2. Aircraft Systems Compatibility: Aircraft systems are designed to operate on a specific frequency, which is often different from the standard power supply frequency of the location where the aircraft is parked.  Electrical systems in aircraft often operate at a higher frequency, commonly 400 Hz. This higher frequency was selected because it enables electrical components to be smaller and lighter, which makes it perfect for aircraft applications.
  3. Ground Operations: When aircraft are on the ground, they need to connect to an external power source to run their systems, perform maintenance, and carry out other tasks. Aircraft frequency converters are used to change the ordinary power supply frequency (such as 50 Hz or 60 Hz) to the higher frequency required by the aircraft (such as 400 Hz) in order to deliver power that is compatible with the aircraft’s systems.
  4. Power Quality and Reliability: Frequency and voltage variations can affect aircraft systems. Frequency converters minimise the possibility of harm to onboard systems and equipment by ensuring that the power provided to the aircraft fulfils the necessary quality and stability criteria.


Choose Your Aircraft Ground Power Units at Red Box

At Red Box Aviation, we have a full range of ground power equipment available. This includes start power units, continuous DC power supplies, and ground power units.

If you need any extra help or advice selecting the best aircraft GPU for your requirements, please contact our team on +44 (0)2380 254285 for a personal service.