Hellow!i want to build a circuit that just turn off electric generator when main power supply comes.

i have a 2.5 kv generator.

please furnished me with opinions.

 

Use a relay. Main power on coil, contacts open to stop generator.

 

which relay i can use? and where to connect in generator?

 

I don't know how the control circuits work in your generator. You did not provide a schematic, a brand name, a model number, the voltage it produces, the number of phases, what kind of fuel it uses, or anything else that is useful. I don't believe you have a 2.5 KV generator. I expect you have a 2.5 KW generator. Even if you provided that information I probably still wouldn't know how to wire it up.

Maybe somebody else will know but you have given nothing to work with.

 

You would need a large DPDT relay (contactor) that can handle the maximum generator and mains current you expect. The wiper contacts go to the household wire, the NC contacts go to the generator, and the NO contacts go to the mains. The mains power is used to power the contactor. The mains power can also be used to control another relay to turn off the generator when mains power is available.

 

That's a change-over circuit. I think the op wants to stop the motor on the generator, but I already had a nice rant about lack of information. Maybe he will come back and clarify.

 

That's a change-over circuit. I think the op wants to stop the motor on the generator, but I already had a nice rant about lack of information. Maybe he will come back and clarify.

I understand. I'm just trying to read between the lines. You wouldn't want to shut off the generator if the house power wasn't switched from the generator to the mains power after an outage.

 

Good point. He will need both circuits, even if he didn't know that when he posted the thread.

 

You need an ATS. I hope you're not connecting both sources at the same time...

 

If you're going to switch between main and generator power with a relay, make sure it's rated at least 2X the line voltage.