5.1 The ship earth station should normally be
powered from the ship's main source of electrical energy. In addition,
it should be possible to operate the ship earth station and all equipment
necessary for its normal functioning, including the antenna tracking
system, from an alternative source of energy.
5.2 Changing from one source of supply to another
or any interruption up to 60 s of the supply of electrical energy
should not render the equipment inoperative or require the equipment
to be re-initialized.