Originally Posted by jrb
400hz -- yes; 150V doubtful!
Maybe. This says 115/200 three phase.
Pretty much a standard:
Ground power units
Ground power unit that needs towing.
A ground power unit is a vehicle capable of supplying power to aircraft parked on the ground. Ground power units may also be built into the jetway, making it even easier to supply electrical power to aircraft. Many aircraft require 28 V of direct current and 110 V 400 Hz of alternating current. The electric energy is carried from a generator to a connection on the aircraft via 3 phase 4-wire insulated cable capable of handling 200 amps. These connectors are standard for all aircraft, as defined in ISO 6858.
Same type of power is supplies as a standard at the Jetway or in a hangar/maintenance facility.
And the ground power involves 28 VDC. Both are supplied to the aircraft. The story involving NEC standards is just a story.
PS I believe that aircraft wiring insulation is rated to 1500V minimum which exceeds NEC standards for housing.