Drydock 50 hz supply, ship 60 hz .What should be done

50 Hz will make motors run slower. 50/60=83% that will have the effect on the efficiency and the connected load .
If we supply a reduced frequency then we also need to reduce the voltage accordingly to prevent the motor to draw more current.
Voltage/frequency of ship equals to Voltage/frequency shore. That’s gives us a calculated voltage of 366 volts, which closer to the standard 380 volts 50 Hz, that can be accepted.
By doing so the through put of the pumps will be reduced, and we definitely have to keep an eye on the temperatures of the motor windings.

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