The TRU is connected to the aircraft three-phase AC network of 115 V AC at a frequency of 400 Hz to supply electrical on-board systems and to load the battery with a DC voltage of 28 V DC. The potential free output voltage is provided over the total range of load and under varying input voltage conditions. The unit is capable to withstand overload for a limited time duration. An integrated fan provides respective ventilation in the specified temperature range. Temperature sensors and integrated monitoring circuits verify the internal unit temperature to remain inside the acceptable limits and provide this status information to the externally connected systems.
A TRU with similar functions but with a fixed connector is available as TRU150B1, and with a different fan as TRU150C1.