4 Breakers all tied together for 120/240 single phase?

[LarryFine]

But why the breakers in parallel? I don't see the advantage, but applying Occam's Razor I see a disadvantage.

How are they rated? Do the ASSume that the current will split perfectly as engineered between the breakers? What if one of the four fails?

I was told by a GE field engineer about 25-30 years ago that each line's pair of breaker bodies is made up of one current-sensing unit and one auxiliary-contact body.

He said this was done for the purpose of reduced overall contact resistance, which I took to mean less FOP across the breaker set. I guess the bodies are cheaper, too.

In more recent times, however, someone (maybe here) said that my explanation is wrong, and the 4-pole unit is really made up of four similar 100a breaker bodies.

So, unless someone wants to drill out the rivets on such a unit and let us know what they find, we may never know the truth. Maybe we can't handle the truth.

 

[e57]

All linked by the trip trigger mechanism - much the way a shunt is added on... Grab a small screw driver - reach in the hole - or use the cam on the side (not energized of course) and give it a shot...

 

[infinity]

and the 4-pole unit is really made up of four similar 100a breaker bodies.

That is the way I've always viewed those CB's. I'm sure that by using 4 single 100 amp units together it becomes the cheapest 200 amp CB that they can manufacture. Personally I see nothing wrong with it since it's part of a tested and listed product.

 

[kwired]

To all that think this is an illegal breaker it is not.

It is not four single poles with a four pole handle tie, is is not two double poles with a four pole handle tie.

It is a double pole breaker main for whatever manufacturer. I think I have seen GE, ITE/Siemens, and maybe others. Some of the earliest Homeline were that way also if i recall.

They are usually 150 - 225 amp frame sizes. It will not plug onto buss to be used as a branch breaker and will only fit in the main breaker position. It looks like and possibly may have 4 poles but is listed for the purpose and is a common trip device.

Most I have seen were factory installed, not sure if any main lug panels were able to be converted to main breaker with this type of main.

 

[norcal]

ITE started those type in the 1970's, the Cutler Hammer all-in-one on my house has the same type of also, perhaps should get a pic of all 3 makes side by side for comparison.

 

[Mgraw]

Most I have seen were factory installed, not sure if any main lug panels were able to be converted to main breaker with this type of main.

They are. I used one on a job after Katrina. All I could get was a MLO so I bought it and the breaker kit. All you need to do is unbolt the lugs on the MLO and bolt the breaker on in the same spot. The dead man has a knockout for the main breaker.