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I found out that outlet lost power after Circuit was overloaded by plugging too many heaters. Believing that resetting the breaker would restore the power, I reset the breaker and the breaker above tripped. Still no power on the dead Circuit.
 

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Discussion Starter #5
I inspected 3 outlets that possibly had 3 electrical heaters plugged in simultaneously and overloaded the circuit. None of these receptacles has a split tab. Could a recreated connection happen at unused outlet in the same circuit? Or is it possible that the overloaded caused a short at the neighboring circuit breaker?
 

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You have two circuits that are cross connected. When you turn on both breakers you are creating a dead short across 240 volts. You need to track down where the two circuits might be meeting up and disconnect that connection.

None of the receptacles has a split tab. But maybe one of them is supposed to have a split tab.
 

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All wiring on the circuit that was overloaded would be suspect. It could be a line to line short caused by the insulation melting. We're assuming this is shared neutral circuit. Have you confirmed that at the panel where you should see these two breakers feeding into the same cable? If that isn't the case, the only way those two phases could get together would be at a junction box... sometimes a multi gang switch box also serves as a junction for wall receptacles.
 

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Make sure if this is a house with Romex or BX cable that the two circuits are not going to a three wire cable like a cable with a black, red, white, and a bare wire if so you are overloading the neutral (white) wire if so the wire will get to hot and trip the breaker.

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Discussion Starter #9
Overloaded neutral is a good explanation. I will start at the receptacle closest to the breaker to look for melted insulation.
Thanks.
 

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An overloaded neutral will not trip the breaker.
 
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Make sure if this is a house with Romex or BX cable that the two circuits are not going to a three wire cable like a cable with a black, red, white, and a bare wire if so you are overloading the neutral (white) wire if so the wire will get to hot and trip the breaker.

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A properly wired MWBC will have the two hots on opposite legs of the panel. The neutral will only see the difference in current, not the additive of current.
 
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Discussion Starter #12
I took a picture of the circuit breaker panel with cover off. But I don't know how to attach it to my reply. The breakers at issue are number 1 and 3 on the upper left corner. Neither breaker nor wires appear to have problems. I believe #3 used to feed outlets only and #1 feeds other lights and outlets. After#3 tripped, I tried to reset the breaker that caused #1 to trip. Odd enough that now #3 seems to feed previous #1 circuit and the #3 outlets are still dead. In other words after the overload problem, #1 and 3 can't be on simultaneously anymore. But now either #1 or #3 will power the original #1 circuit. Still can't get power to the outlets believed to be tied to #3 CB.

Thanks for your help.
 

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Are both of those breakers plugged in next to each other in the panel or is there a space (another breaker) between them? Are they full size breakers?

To attach a picture to a post, click on "Go Advanced" and then click the PAPER CLIP icon... then migrate to your file location and select the file and click OPEN then click UPLOAD.

None of that really matters as far as locating the problem, it just helps understand what might have caused it.

It seems obvious that the circuit has melted something down and shorted the phase conductors together. Your work is cut out for you, you'll have to expose all receptacles on those two circuits and hope to find one that has burned down. If that fails, the cable itself may need to be replaced if it has melted down and shorted. That can happen if a MWBC isn't phased properly and the neutral gets extremely hot.
 

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That type of wiring overload short would more likely occur at a receptacle box where the wires are jammed together tightly, rather then inside the cable.
 

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Discussion Starter #15
If I reply here I can only write and submit reply. I can't find the file attachment button. The #1 is at the upper left corner and #3 is right under#1. Currently #1 is in off position. I have all lights and some outlets with power. 5 outlets are dead. If I turn off #3 and turn on #1, there's no difference. Come to think of the lights and live outlets may be powered by other CB.
 

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Discussion Starter #16
#1 CB is at the top upper left corner, currently at off position. #3 CB is right under #1. Could melting happen at an unused outlet when overload happened? The 3 outlets that are dead didn't show any signs of burning or melting. 2 other outlets are dead but we're never used. So I haven't examined the condition yet. What puzzling is after the overload #1 and #3 circuit becomes identical and is powered by either #1 or #3 CB. But #1 and #3 can't be on simultaneously. I think that's why I have 5 dead outlets. Some outlets and all lights in the room are still on regardless I have #1 or #3 CB on
 

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Pictures can fool the eyes but this picture begs the question... How are 15 branch circuits being served by only 6 neutrals? That presumes that it isn't a 3-phase panel (can't see the feeders).

It requires 8 neutrals minimum to supply 15 branch circuits on panel with only 2 phases in it and could require as many as 15.

Perhaps there are some more neutrals landed on a terminal strip that was off camera.
 

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Examine those neutrals closely to see if any look like they have discolored from excess heat... makes them darker or less shiny.

I've put in lots of 3-phase panels and the sequence of the conductor colors in that panel is exactly the way I color phased them. That may or may not mean anything in this case until we see the feeders.

Also noticed is that no NM sheathed wires are entering the panel. Perhaps the wiring is in metal conduit??? Or perhaps the NM terminates in a junction box and individual conductors of TW, THHN or whatever are run from there to the panel??? That junction box, if exists, could be where the fault lies??? Possible.
 

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Could melting happen at an unused outlet when overload happened?
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Yes, anywhere on the circuit between the panel and the overload point is subject to the overheat issue, even though the receptacle at that point isn't being used.
 
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