3 Phase Load to Single Phase breakers??

[DLCOX]

Hey,

Got question or really confusion/lack of understanding on my part.

We have 3 phase 65kW Load Banks @208V,...originally a single 225A breaker was going to be used. However, because 50 of these Load Banks are needed that would mean a lot of 225 amp breakers which arent cheap. So the idea was thrown at me that instead of one 225 amp bkr use 3 three 100 amp bkrs (cheaper and have a surplus) per load bank. No problem to me but I'm having a hard time understanding how this setup will look ie the connections. Does this mean, they are referring to each phase having its own bkr? If so what type of 100 amp bkr would it be, 3 ph or single ph?

slightly confused

DC

 

[augie47]

sounds as if the plan would be to connect the breakers in parallel which is prohibited under NEC 240.8

 

[DLCOX]

I totally agree

 

[Jraef]

sounds as if the plan would be to connect the breakers in parallel which is prohibited under NEC 240.8

Unless listed like that by the breaker manufacturer as a single breaker. (you see it on main breakers in load centers a lot, however I can't remember ever seeing it in 3 phase).

Even so, EACH BREAKER would need to be rated for 225A, the 100A issue is totally incorrect no matter what you do.

 

[charlie b]

Since a new thread has been started on a similar topic, I am closing this older version. We don't allow duplicate discussions. The other thread is here:
http://forums.mikeholt.com/showthread.php?t=181827