Hi Torhav,
I will certainly try to answer your questions.
1: A generator is connected to a ships main supply. The generator is out of sync 10 degrees. The generators voltage (6.6kV) matches the voltage in the main supply. What is the voltage on the breaker?
This seems an odd question.
It could be that there is a mistake here somewhere.
You see, if the generators breaker is closed then the voltage would be the same either side of the breaker.
So the voltage on the breaker is 6.6kV
The current from the generator can be 'out of phase' and this shows on the power factor meter. If its in reverse then it may have to be corrected within a given period, as some arrangements are set to reject the generator taking power from the main supply, and may trip it out.
The current from generators is always out of phase, the power factor on most generators is around 0.7 roughly. (0.6 to 0.8)
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2: What happens if the generator is connected with opposite fases?
Again, an odd question.
I am going to guess that you mean what would happen if the breaker is closed when the incoming voltage(s) is/are 180 deg out of synchronisation ?
In that case, there would be a rather loud bang. Various fuses would blow.
The breaker would have to be taken out of service for overhaul. The service electricians would be brought in to check lots of things. The operator who was in charge of the switching would be questioned, if he/she was at fault they might be reprimanded or sent for re-training.
There would be a jolt of some sort through the ships electrical system, and many sections would have to be subsequently checked out to make sure that they are Ok.
This sort of thing has happened before, and no doubt will again.
There will be a procedure and probably a list of checks for the service electricians to go through.
Most latter day generators are made to synch up and go on line from their own control units. It is unusual these days to have manually operated switching on these powerful 6.6 kV units.
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What has prompted these questions ?
John