Delta circuit breaker

[Jomaul]

Can someone explain to me what a Delta circuit breaker is and where it is used. I spent a lifetime as an residential electrician and contractor and have never run across this type of breaker.

 

[roger]

It's an obsolete breaker that would attach to the busses of a single phase panel for two of the phases and an additional set of lugs that would allow a "high leg" (Line and load) to also connect to it.

This allowed a three phase OCPD in a single phase panel.

They were disallowed sometime in the 70"s I believe.

Roger

 

[izak]

if i recall correctly it takes up 4 spaces, but has three handles, all tied together, like a three pole breaker...

 

[norcal]

Here is a picture from another forum,the prohibition first appeared in the 1978 NEC 384-16(e).


http://www.electrical-contractor.ne...ubb/showflat/Number/152376/page/16#Post152376

 

[templdl]

This is a hidden application note from Cutler-Hammer:
Delta Breaker VS. Breaker used with Delta Systems - Technical Data
http://www.eatonelectrical.com/unsecure/cms1/LT00301005E.PDF
Here's another:
Molded-Case Circuit Breaker Individual Pole Interrupting Capability
http://www.eatonelectrical.com/unsecure/cms1/TD01220001E.PDF

 

[norcal]

If one reads that PDF docu. from Eaton, http://www.eatonelectrical.com/unsecure/cms1/LT00301005E.PDF it seems a little horse pucky is being spewed forth, as I have a CH360D delta breaker in my stash. C-H did make them.

 

[JohnConnolly]

I replaced a panel on a fire job caused by an AC guy. His helper turned off the breaker, disconnected the HOT leg and let it go to ground. The fuse link on the pole transformer finally popped but the wall behind the panel was already in flames.

Good times.

PS. I learned how to make one out of 3 single pole breakers in a pinch (Zinsco style only)