400Hz Ground Power Unit — Diesel-Driven (40/60/90/140/180 kVA), made by MAK Controls & Systems

The MAK diesel-driven GPU is a self-contained 400Hz alternating-current power supply designed to sustain aircraft electrical systems during turnaround without running the aircraft's own APU. Powered by a Cummins or Deutz diesel engine coupled directly to MAK's own brushless, Class-H insulated alternator with integrated AVR, the unit delivers 115 V (L-N) / 200 V (L-L) three-phase power at 400 Hz across five standard output ratings — 40, 60, 90, 140 and 180 kVA — covering everything from regional turboprops to wide-body freighters. The unit serves ground handlers, MRO facilities and military ramp teams that need reliable power for avionics, cabin systems, hydraulic rigs and engine-start via electric starter. Voltage regulation holds within ±1% under steady state, with transient recovery from a ±20% disturbance within 200 milliseconds — performance that protects sensitive aircraft avionics. Total harmonic distortion stays below 2%. Output protections — under-voltage, over-voltage, overload trip and phase-rotation verification — prevent aircraft power-bus damage. Engine safeguards include automatic low-oil-pressure and high-coolant-temperature shutdowns. The touchscreen control panel provides real-time load, battery voltage and engine-parameter display; MAK's RDMS fleet-management software connects the unit to a remote workstation or mobile device for fault alerts, usage logging and preventive-maintenance scheduling. Available in towable trailer, self-propelled and skid-mounted-for-truck configurations, the range is suited to hub airports needing rapid gate-to-gate turnarounds and to forward-operating bases in high-ambient environments. The Tier 4 Final diesel compliance and enclosed weatherproof canopy make it operable in the high-temperature, dusty conditions typical of GCC ramp operations.