odd arrangement of 2-pole breaker ties

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muhandas

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I hope someone can help me understand what I?m looking at. Please refer to the partial picture of a main residential panel below. I have not taken the panel cover off (yet) to see what the OCPDs in question look like from the rear.
Look at the top two breakers. Each appears to be a double pole breaker and each breaker has one 20A and one 40A breaker in the same housing. Both the water heater and the range are 240V appliances and each is served by the two corresponding halves of each of the breakers. Both breakers have handle ties, the inside 40A ones for the range (one pole from each breaker) are linked with looks like a more or less conventional handle tie, and the outside 20A ones (again, one pole from each breaker) for the water heater are linked with what I think is a made tie. It may not be but I haven?t seen this before.
My question is why would this system be used instead of the more conventional way, one double-pole 20A and one double pole 40A breaker? Why would one even use a double pole breaker with different A ratings for each of the poles? I didn?t even know such beasties were manufactured.
I?m sorry folks but my ignorance is vast and I hope for some enlightenment.
Heinz R.
 

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Very common with old Bryant/Westinghouse/CH breakers.

Quad_Breaker_220220_A.jpg


QuadCH.jpg


QuadCH2.jpg
 
That is a factory assembled unit not field installed handle ties. It is essentially a "tandem" double pole breaker. They are common on manufactured and mobile homes.

The panel is likely designed to only accept these in certain locations - smaller panels may be designed to accept them in all positions. They use the same rejection method the single pole tandem breakers use.
 
kwired said:
That is a factory assembled unit not field installed handle ties. It is essentially a "tandem" double pole breaker. They are common on manufactured and mobile homes.

The panel is likely designed to only accept these in certain locations - smaller panels may be designed to accept them in all positions. They use the same rejection method the single pole tandem breakers use.
Click to expand...

Just about every mobile home I have seen has these type breakers. And run the same load HWH and range.
 
Why is the "quad" arrangement preferred over the more usual 2 double-pole breakers? Is it cheaper to do it this way?
Heinhz R.
 
definately is not cheaper for most of us, I'm sure the manufactured home builders buy in larger quantities and get a better price. But I've been told they are more concerned with space and weight. Weight is in part to the fact that this home has to travel down the road at some time.
 
I always knew them as a quad breaker and used them way back in the early 80's. It's just two twin breakers set up as double poles. It takes up less space in the panel than two full sized double pole breakers. Sometimes that was the only way I could add a 220V circuit to some panels without replacing the panel or adding a sub panel.
 
muhandas said:
Look at the top two breakers. Each appears to be a double pole breaker and each breaker has one 20A and one 40A breaker in the same housing.
Click to expand...
Exactly, just like any tandem breaker. The quad is merely two tandems joined as two 2-pole breakers.

My question is why would this system be used instead of the more conventional way, one double-pole 20A and one double pole 40A breaker?
Click to expand...
As mentioned above, to use fewer panel spaces. A panel with a label that says, for example, "20 space/30 circuit," is intended to accept as many as ten tandems (or the equivalent in quads.)

Why would one even use a double pole breaker with different A ratings for each of the poles?
Click to expand...
Okay, as with all tandems, the two breakers within each body are two single breakers, and not a 2-pole. That's because both halves receive their power from the same bus stab.

When using tandems, it's very important to remember to land each line conductor of a pair on a terminal of the other body. If you don't, there will be no voltage between the two.

For a 240v-only circuit, that merely leaves you without any 240v power. But, in the case of two 120v circuits sharing a neutral, that can allow overloading and damage to the neutral.

They also make "triplex" breakers that contain a 2-pole breaker flanked by two 1-pole breakers; basically, what you showed minus the larger handle tie (which is factory, not added.)
 
Now thats not confusing. Take a look at this prize. I bought a large quantity of breakers 17+ years ago and got a case of these factory mistakes.

PDRM0005.jpg
 
acrwc10 said:
Now thats not confusing. Take a look at this prize. I bought a large quantity of breakers 17+ years ago and got a case of these factory mistakes.

View attachment 5327
Click to expand...


Just curious. Ever try to put a load on one to see if the
"50" trips at 30 or so amps. I would wonder if it was a case of
just the wrong handles.
 
augie47 said:
Just curious. Ever try to put a load on one to see if the
"50" trips at 30 or so amps. I would wonder if it was a case of
just the wrong handles.
Click to expand...

Not yet, I always seem to have something more pressing to do. :)
 
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