5.1.1 Short-circuit protection, an overload alarm and, in the case of polyphase
circuits, an alarm to indicate single phasing is to be provided for each main and
auxiliary motor circuit. Protective devices are to operate at not less than twice
the full load current of the motor or be circuit protected. They are to allow excess
current to pass during the normal accelerating period of the motors.
5.1.3 Indicators for running indication of each main and auxiliary motor are
to be installed on the navigating bridge and at a suitable main machinery control
position.
5.1.4 A low-level alarm is to be provided for each power actuating system and
hydraulic fluid reservoir to give the earliest practicable indication of hydraulic
fluid leakage. Alarms are to be given on the navigation bridge and in the machinery
space where they can be readily observed.
5.1.5 Two exclusive circuits are to be provided for each electric or
electrohydraulic steering gear arrangement, consisting of one or more electric
motors.
5.1.7 One of these circuits may be connected to the motor of an associated
auxiliary electric or electrohydraulic power unit.
5.1.8 Each of these circuits is to have adequate capacity to supply all the
motors which can be connected to it and that can operate simultaneously.
5.1.9 These circuits are to be permanently separated and as widely as is
practicable.
5.1.10 In units of less than 1600 gross tonnage, if an auxiliary steering gear
is not electrically powered or is powered by an electric motor primarily intended
for other services, the main steering gear may be fed by one circuit from the main
switchboard. Consideration would be given to other protective arrangements other
than what is described in Pt 5, Ch 19, 5.1 Electric power circuits 5.1.1, for such a motor which is primarily intended
for other services.