3.3.1 The
main busbars of the switchboard supplying the propulsion machinery
and essential services are to be capable of being isolated by a multi-pole
linked circuit breaker, disconnector, or switch-disconnector into
at least two independent sections.
3.3.2 In
the event of the loss of one section or failure of the power supply
from one generator, there is to be continuity of sufficient electrical
power to supply essential services such that the available installed
prime mover capacity and installed propulsion systems will continue
to have the ability of functioning at their operational capability
where PSMRL, PSMRL
, PMRL and PMRL
notations are required. See
Pt 5, Ch 22, 3.2 Steering machinery 3.2.1 for steering machinery requirements.
3.3.3 In
the event of the loss of one section or failure of the power supply
from one generator, there is to be continuity of sufficient electrical
power to supply essential services such that the ship will retain
not less than 50 per cent of the prime mover capacity and not less
than 50 per cent of the installed propulsion systems where PSMR, PSMR
, PMR and PMR
notations are required. See
Pt 5, Ch 22, 3.2 Steering machinery 3.2.1 for steering machinery requirements.
3.3.4 For
ships capable of operating with one service generator connected to
the switchboard, arrangements are to be such that a standby generator
will automatically start and connect to the switchboard on loss of
the service generator. Sequential starting of essential services is
to be provided.
3.3.5 For
ships operating with two or more generator sets in service connected
to the switchboard, arrangements are to be such that, in the event
of loss of one generator, the remaining set(s) is to be adequate for
the continuity of essential services supplied from that switchboard.
This may be achieved by preferential tripping of non-essential services.
Alternatively, arrangements can be such that a standby generator will
start automatically and connect to the switchboard on loss of one
of the generator sets in service.