Tronair 112860S0200 – Single-Output 28V DC Aircraft Rectifier/Ground Power Unit (GPU) (CE) - 60 HZ

Tronair will not retap or rewire ground power units (GPUs). The unit will be wired and labeled at a certain voltage at the time of shipping. Once you receive the unit, you will need a qualified electrician to hook the cable up to the hangar and wire the inside of the transformer correctly to match the input voltage of your hangar. Please refer to the Operation & Service Manual for this unit to ensure proper setup.

Operators must follow standard electrical safety procedures, including wearing protective equipment and verifying system grounding before connection. The GPU features built-in circuit breakers and overvoltage protection, but users should always ensure the unit is de-energized before performing maintenance. The manual warns against using the GPU in wet or hazardous environments unless properly protected. Following all lockout/tagout procedures is crucial during service to prevent accidental energization.

The Tronair 112860S0200 uses an air-cooled system driven by internal fans that activate when the unit is powered on. This cooling mechanism is designed to handle continuous duty cycles under typical ramp conditions. To prevent overheating, it’s important to maintain proper airflow around the unit and avoid blocking vents. Routine inspection of the fan and air passages ensures reliable thermal performance.

To connect the GPU to an aircraft, align the 28V DC output connector with the aircraft’s external power receptacle, ensuring a clean and secure fit. The connector must be compatible with standard MIL-C-24308 configurations, and any signs of damage or wear should be addressed before connection. Once connected, the unit can be powered on using the switch on the front panel. Users should never force the connection or bypass safety interlocks.

The front panel features visual indicators to provide real-time system status. These include power-on, output enabled, and fault/overload LEDs, which help the operator monitor safe operation. An ammeter and voltmeter are also included to verify that the voltage and current output are within safe operating ranges. These features allow the user to quickly assess if the GPU is functioning correctly or if an adjustment or shutdown is needed.

The unit is designed with mobility in mind, featuring heavy-duty casters and a compact footprint. The front-mounted handle allows for easy repositioning by one person, though care should be taken when rolling over uneven surfaces. With a ruggedized steel housing and a total weight of approximately 750 lbs (340 kg), this ground power unit strikes a balance between durability and maneuverability for both hangar and ramp use.

The unit is compatible with most aircraft that require a single-output 28V DC external power supply. It’s especially suitable for turboprops, helicopters, business jets, and light military aircraft that rely on 28V systems for battery charging or ground system checks. However, compatibility depends on the aircraft's receptacle type and power requirements, so it’s vital to verify connector and amperage compatibility before use.

The Tronair 112860S0200 includes overload protection, overvoltage shutdown, and thermal cutoff to safeguard both the GPU and the connected aircraft. If excessive current is detected, a circuit breaker trips to prevent damage. Additionally, thermal sensors will shut down the unit if internal temperatures rise beyond safe limits. These built-in features protect aircraft systems from unintended voltage spikes and help ensure long service life for the GPU.

While the unit is built with durable enclosures, it is not rated for direct water exposure. If moisture enters the housing, it can compromise internal circuitry and trigger fault conditions. Per the manufacturer, the unit should always be operated in dry conditions or under protective cover. If exposed to rain, the GPU should be thoroughly inspected and dried before subsequent use.