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What type of circuit breaker is this?

zepfan
zepfan Member Posts: 419
in THE MAIN WALL

does anyone know what is special about the circuit breaker that is in the top right of the below pictured electrical panel? It is a 100 amp breaker that serves an electric heat panel that is on the side of the main electric panel. The breaker has a black enclosure on the left side, which appears to be part of the circuit breaker. The pictured breaker is defective, and we need to replace it. My concern is that we will not be able to find one locally quick, and I was thinking of just replacing it with a 100 amp breaker and relocating the circuit to the lower part of the panel where there are empty spaces.
thanks to all

IMG_4093.jpeg

Comments

  • mattmia2
    mattmia2 Member Posts: 11,610
    edited February 6

    square d qo. looks like it is 3 phase. if you get the part number off it, it should help you find one. i know the larger breakers use 4 adjacent spaces but those are usually 150A+. perhaps they just couldn't make a 3 phase 100a breaker the size of a normal double slot.

    is that an aluminum bus or is it tinned copper? i think all modern qo is tinned copper. that could be a factor too.

    kcoppzepfan
  • Steamhead
    Steamhead Member Posts: 17,599

    Sure that's not the main breaker for that panel? Looks like one………………………….

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    zepfan
  • mattmia2
    mattmia2 Member Posts: 11,610

    what is on the other side? is it an auxiliary trip breaker or one with dry contacts to indicate state?

  • mattmia2
    mattmia2 Member Posts: 11,610
    edited February 6
    https://forum.heatinghelp.com/discussion/comment/1840593#Comment_1840593

    looks like it is probably a commercial main lug subpanel and the overcurrent protection is on the feeders at the switchgear.

    zepfan
  • zepfan
    zepfan Member Posts: 419

    thanks to all that responded. I agree it looks like the main breaker for the whole panel, but there is a 300 amp main breaker for the panel, that is not shown in the picture. This breaker is strictly for the electric heat panel.

  • Larry Weingarten
    Larry Weingarten Member Posts: 3,699

    Hi, Is this three phase? I did a search for "square d qo 3 phase breakers 100a" and your breaker looks similar to what I found. 🤔

    Yours, Larry

    zepfan
  • 109A_5
    109A_5 Member Posts: 2,095
    edited February 6

    Connections to the buss-bar OK ?

    image.png
    image.png
    National - U.S. Gas Boiler 45+ Years Old
    Steam 300 SQ. FT. - EDR 347
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  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 17,131

    Strange panel. Its 3 phase all right but it must have 3 busbars running down each side of the panel.

    Wonder what is up with all the white wire

  • mattmia2
    mattmia2 Member Posts: 11,610
    https://forum.heatinghelp.com/discussion/comment/1840638#Comment_1840638

    it is definitely very old, like i was surprised to see visi-trip breakers old

  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 17,131

    @mattmia. What am I still doing up at 1 am on HH?? LOL

  • ratio
    ratio Member Posts: 3,886

    Looks like it might be an A1B3100. Schneider doesn't show a listing for that any more, but I bet the Old Guy at the counter of your local Square D supply house will know about it. I suspect that it's just that big because they needed the extra space to make on that big. It might be rated for higher than 10kAIC as well.

    zepfan
  • zepfan
    zepfan Member Posts: 419

    thanks to all that responded. Then end of the story was that a SQ D standard QO breaker did fit in the panel, and work. I ended up calling Schneider electric, which were very helpful, before I bought the breaker to make sure it would work. Even though the breaker I took out was 50+ years old, I still don’t know what the black enclosure was for. Thanks to all.

    IMG_4098.jpeg
  • JUGHNE
    JUGHNE Member Posts: 11,339

    That design was used often as a back feed Main Breaker for a panel.

    It provides twice the contact clips to the buss bar to improve conductivity and reduce heating of the buss bar you might have with only one clip doing the job.

    They had provisions on the ends to lock the breaker down to the mounting rails if it was used as a back feed breaker.

    zepfan
  • mattmia2
    mattmia2 Member Posts: 11,610
    edited February 7
    https://forum.heatinghelp.com/discussion/comment/1840833#Comment_1840833

    I would rather see the 150A+ breaker or the 150A buss tap that uses 2 adjacent stabs and overcurrent protection at the load than a continuous 100a load on a single set of stabs. Most things that use a 100a breaker are very infrequently loaded at 100a. Of course is the heater attached to it 80a or is it much smaller? Or is it several circuits out of a subpanel that is rarely all calling at the same time?

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