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I have a range and it runs 240 through the attic and then splits off in the attic to two 120 lines to the breaker box but whoever installed it before did not do it right because the range wasn't working and when I found the problem the wires had melted.

Does that mean it gets too hot or just wasn't capped off right? They had electrical tape around it instead of wire nuts. Could that be why the melted on the connections?

I connected it this time the right way but I just want to make sure it's fine and it's not going melt again

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    I take it by "range" you mean electric range? What gauge wires are involved here, what size is the circuit breaker, and how many kW does the range draw? Jan 26 '19 at 15:54
  • Voting to close for lack of detail. OP hasn't been back.
    – isherwood
    Apr 2 '19 at 17:25
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Electric ranges usually use size #8 American Wire Gauge (AWG) conductors. What does the rating plate on the electric range say? The wires must be large enough to handle the rated Amperage, and the breakers must also be sized correctly. What size are the wires in the attic? If they are too small a gauge they could melt from too much heat in the line, caused by too much resistance, like trying to force Niagara Falls through a small garden hose ....

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With just tape on the splice there was probably not a good connection. When wires do not have a secure connection they start arcing and melt the wires. As long as the wires are sized correctly (At least 8 awg) and you have used large wire nuts tightened properly you have solved the problem. Fyi the splice should be in a box. Boxes help to contain a fire that can happen when a splice fails. Many times I have found home owner or DIY repairs that have failed because they were not in a box and someone working in the attic had bumped stepped on or pulled the wires causing a failure they did not find until later, a box houses the splice and the clamps keep the wires from being pulled apart. Good job on finding the failed splice and repairing it as long as the wires are properly sized you should be fine.

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RED ALERT! This is a DANGEROUS situation!

Sorry. Not often do I trot out the klaxons and flashing lights, but THIS SETUP WILL KILL YOU. It's not your fault it got this way, but that makes it no less lethal. In fact, the failure was your lucky break; it could have failed far more "silent but deadly". Make the most out of your luck.

This must be removed from service immediately.

These wires are simply incapable of supporting a range, and if you want to continue with the range, you'll need to run a new 6/3 or 8/3 cable from the range location to the service panel.

Short-term, you need to change the breakers in the panel to an appropriate value for the wires.

Here's what happened.

Joe Firstguy switched from a gas to a 120/240V electric range. He knew just enough electrical to know that panels have two poles, and that if you tap two 120V circuits that are on opposite poles, you find 240V. Perhaps he's hooked up floor polishers or compressors this way before. Anyway, rather than run the proper 8/3 or 6/3 homerun, Joe found two 120V branch circuits for bedrooms or something. They were probably 15A (maybe 20A). And he tapped those circuits to get 240V for the range.

This is ugly and illegal, but perhaps Joe was smart, and left the breakers at 15A to avoid thermal overload of the wires. He just warned his wife "only use one burner at a time". Maybe. But anyway, along comes Bob Nextguy. Bob uses many burners, keeps tripping breakers, so he upsizes the breaker. He just remembers "these wires are small, only use 2 burners at a time". Now the trap is set.

Then you get the house, and nobody tells you the burner thing. The breakers are way too large to protect the wire. The range can pull 40-50 amps on top of the normal loads already on the branch circuit. That quickly overwhelms the circuit's wiring. You got lucky and got a splice burnout instead of an in-wall fire.

Anyway, your first stop-gap is to roll those breakers back to a size appropriate for the wire; 15A if you're don't know the're 12AWG. That will at least prevent a fire.

Then as soon as you can, fit the 8/3 or better 6/3 cable to power the range properly.

If you mend the burnt wires but don't downsize the breaker, you'll just move the problem to somewhere inside walls. Don't do that.

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  • Almost every range works off 2 120v lines. Unless we know the wire size we cannot say it is overloaded, the op said they were taped , that's all we know for sure and on a large load like a range a loose connection would be enough to burn any size wires off.
    – Ed Beal
    Apr 2 '19 at 13:25
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    @EdBeal Every range works off 2 paired 120v lines - i.e., common trip in the panel. splits off in the attic to two 120 lines implies "2 separate lines, which might be common trip or might not, might be common neutral (MWBC) but might not, might even be circuits on the same pole. The key is "splits off in the attic". That is a huge red flag. Based on that, Harper's assumption of "goes to ordinary circuits" is a good one. I'll note that it could be 20A almost as easily as 15A but that is little comfort with a 30A or larger current draw. Apr 2 '19 at 14:20
  • Until the op states the type of wire and size I stand by we don't know. I have had 500kcmil wires burn off from a loose connection, tape alone is not enough and that's all the info we have. Someone that dosenot understand 240 may call it 2ea 120v lines.
    – Ed Beal
    Apr 2 '19 at 15:53
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    @isherwood I significantly rewrote that section, hopefully got rid of any condescension, and created an appropriate level of drama. Read OP carefully, there's no doubt the range connection was improvised by joining two separately cabled 120V circuits in a junction in the attic. It's also clear that the wiring is extremely hokey. Have you ever seen a 120V circuit that was 40/50A or even 30A, let alone two? No, these could only be lighting/receptacle circuits, 15-20A. Apr 2 '19 at 17:02
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Sounds like each leg booted from possibly two single breakers. Sometimes you'll find more circuits added to these 120 legs...not good in my opinion. Safety loads are calculated and organized for a reason. So things won't heat up, kick a breaker, etc. I'm trying to understand how you wired it. Just don't know how it was initially wired and how you fixed it is all. Thank you.

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  • Chad, this seems more like a comment than an answer.
    – isherwood
    Apr 2 '19 at 12:47

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