Technical notes of interest to Marine Engineers
Synchronizing generators
Authored by: Martin Leduc, 1998
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The DEV Galena
has four generator sets. Three running under normal
operating conditions. It is, on some occasion, necessary
to service a running generator set. This requires the
engineer to bring on line the fourth generator, then
taking the desired generator off line. This is done as
follows:
1) Bridge should be notified of intended action.
2) ME start. Prime engine with fuel by hand pump. Turn off engine block heater, flick engine control switch to ‘on’ . Turn on air valve, and depress air control valve. Engine should start. Check oil pressure, check for circulation of cooling water (by feeling pipes). Close air valve. Repeat procedure for next two engines.
3) Synchronizing of generators. Check control room engine gauges. When satisfied, turn to generator control panel. Ground lights should be checked for equal brightness, and reverse relays reset if need be. The lead generators should already be set at the desired Voltage (480V) and Hertz (60), if this is the case, the generator being brought on line will adhere to these parameter (via the AVR). Once those checks have been performed, proceed to the next step.
4) Switch synchronizing relay to ‘on’, adjust generator speed to obtain a steady slow movement of the needle in a clockwise fashion. When the needle has travelled 3/4 of the way, depress breaker close button. The breaker should energize when the needle reaches the 11 o'clock position on the synchroscope guage. The on-coming generator should now be taking load with the same parameters as the other generators on the bus (ie: volts @ 480, hertz @ 60).
5) At this point, governor controls should be switched to the desired generator. The load, indicated by gauges, should be slowly removed from desired generator until it is not contributing to the bus of the system. At that point, quickly trip breaker before the desired generator becomes a load to the system -reverse power.
6) With the desired generator off-line, the engine may now be stoped using toggle switch. The engine block heathers should be turned on at this point. A final check should be made to the control panel to assure proper settings, even production, and distribution from the generators. You are now ready to service the desired generator.