3P breaker with neutral contactor Vs 4 Pole breaker
3P breaker with neutral contactor Vs 4 Pole breaker
(OP)
Hi guys, I just want your opinion about a system:
I have a turbing generator star connected. The supplier is suggesting a 3 Pole ACB with neutral contactor. The ACB rating is 630A, 415V.
What will happen if I use 4 Pole ACB without neutral contactor?
Please suggest whether a system will work:
1) If I use 4P ACB without contactor?
2) Or I have to use 3 Pole ACB with neutral contactor?
3) Or I can go ahead with 4 pole ACB with neutral contactor?
Please suggest about this..
I have a turbing generator star connected. The supplier is suggesting a 3 Pole ACB with neutral contactor. The ACB rating is 630A, 415V.
What will happen if I use 4 Pole ACB without neutral contactor?
Please suggest whether a system will work:
1) If I use 4P ACB without contactor?
2) Or I have to use 3 Pole ACB with neutral contactor?
3) Or I can go ahead with 4 pole ACB with neutral contactor?
Please suggest about this..






RE: 3P breaker with neutral contactor Vs 4 Pole breaker
While using a 4 pole device, the neutral contact shall be first to close and last to open (called overlapping neutral in the ANSI world).
Rafiq Bulsara
http://www.srengineersct.com
RE: 3P breaker with neutral contactor Vs 4 Pole breaker
Switching with a separate contactor will be a code violation in many jurisdictions. Consider the impact on your system when the contactor fails and leaves your neutral open.
A 4 pole breaker with overlapping neutral is your best choice if you must switch the neutral. Some jurisdictions will accept a 4 pole breaker without overlapping neutral if the 4 poles operate simultaneously.
Bill
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Jimmy Carter