Preferential trip on ship
Preferential tripping in ships is to avoid total black out in the ship
>Operate after a fixed time delay, causing non-essential loads to be shed.
>Usual setting for overload trip is 150% load [50% overload].
Preferential Trip comes into operation as follows.
First tripping at 5 sec:
First tripping at 5 sec:
Shut down non-essential loads [air condition, entertainment, accommodation fans, cargo hold fans, amplifiers, etc.] to reduce the generator load.
Second tripping at 10 sec:
Shut down essential loads [services required for running the ship properly, leaving the
loads of top priority services to maintain Propulsion and Navigation ]
loads of top priority services to maintain Propulsion and Navigation ]
if generator load is still high.
Third tripping at 15 sec:
Shut down the main generator as last action, if the load is still too high, it may be
due to short circuit or insulation breaking
due to short circuit or insulation breaking
.