[bam4800]

The #8 4-conductor cable smoldered in the metal junction box behind my oven. A wire nut melted and turned to a blob at the bottom of the box. My oven control board was ruined, either as result or the cause of the meltdown. The conductors themselves look "blackened" but not melted. The cable is a bit too short to simply cut the black end off, so do I have to replace the whole cable to the breaker box.? Orher safe ideas?

 

[HandyAndyInNC]

Figure out what caused this issue. I would replace it all, including the breaker. The breaker should have kicked. This time leave some slack in the wall behind the box, and use a larger box. Are the conductors made of aluminum? Just curious as to what would have melted a wire nut. Of something get under the nut that was not supposed to be there. I always tape the wire nuts for this type of thing. Keeps dust and debris out of them

 

[J. V.]

My first question is why was there a wirenut in that box to begin with? That cable should have been directly connected to the receptacle. There is no good answer as to why it was not.
Turn off the breaker. Then I would take the all the wires and pull them out of the box so you can see them good.
Take a cloth with some cleaner on it and clean up the wires. They very well may just be black from the soot.
Once cleaned up check each one and cut off just enough to get fresh wire. Your new receptacle will have pressure plate connections so a shorter wire can be used.

If there is no saving the existing wires, you most likely will have to replace the whole cable.
You may be able to set an accessible junction box next to the receptacle box to make up new clean connections and then run new to the range receptacle.
Do you have a basement? You could set the box down there and pull new up.

 

[daveb1]

Your two biggest concerns should be what caused the wiring to melt and what caused the breaker to not trip?

Replace the breaker with one of the proper amperage rating for your stove. Be sure that the new breaker is the proper brand for your panel.

If you can't get enough slack to remove all the singed wires, you may have to replace a section back to an accessable location and do a splice in an approved electrical box. Hopefully you can find a location that's suitable rather than replacing all the way back to the panel.

 

[seharper]

Figure out what caused this issue. I would replace it all, including the breaker. The breaker should have kicked.

Breakers aren't supposed to kick for series arc faults unless they are arc fault breakers. An arc fault is amply capable of doing this.

Just curious as to what would have melted a wire nut.

A limp wristed wire nut job, of which the usual sign is someone taping the nut and wires, because their experience is if they don't, the wires fall out of the nut! They figure if they tape them they won't fall apart. What they're overlooking is the connection inside the nut is loose and won't do its job.

Or something get under the nut that was not supposed to be there. I always tape the wire nuts for this type of thing. Keeps dust and debris out of them

oops Present company expected, of course Well, I have my doubts that a properly torqued wire nut will *allow* anything to worm its way between the two wires. Those wires are pushed together tight, forced into a very tight spiral, and dug into a bit by the metal wire-nut "threads". They aren't just "held against each other".

 

[HotRodx10]

Can you move the receptacle to a different spot on the wall where you'd have more of the cable to work with? For instance, if the cable comes down from the top, install a new receptacle a few inches higher on the wall than where it's at.

 

[Oldmaster]

Do you have a wall oven or a free standing range with an oven?

 

[jbfan]

Can you move the receptacle to a different spot on the wall where you'd have more of the cable to work with? For instance, if the cable comes down from the top, install a new receptacle a few inches higher on the wall than where it's at.

I don't see anywhere they mentioned a receptacle! I'm thinking wall oven and a loose connection.

 

[HotRodx10]

I don't see anywhere they mentioned a receptacle! I'm thinking wall oven and a loose connection.

A couple people recommended installing a receptacle and matching it with an appliance cord for the oven. I agree with that recommendation. The connections for the wires on the receptacle and for the cord at the oven are made to connect wires of that size. I know it can be done, but as the issues with the existing connection demonstrate, connecting #8 wires with wire nuts is a questionable practice, especially for solid wires. Other places I looked recommended either a split bolt or a compression lug connectors for making direct wire to wire connections on wires that size.

 

[Oldmaster]

Wall ovens typically come with a short length of Greenfield with high temperature wire. The purpose of this is to disapate the heat before the connections. There is no cord made that can withstand the heat of the oven.

 

[betelgeuse]

Those wires are pushed together tight, forced into a very tight spiral, and dug into a bit by the metal wire-nut "threads". They aren't just "held against each other".

:vs_clap:If the wire nut burnt up, then it was loose.

 

[betelgeuse]

I know it can be done, but as the issues with the existing connection demonstrate, connecting #8 wires with wire nuts is a questionable practice, especially for solid wires.

There's no such a thing as #8 solid, except for bare ground wire and the wire that the utilities use

 

[HotRodx10]

There's no such a thing as #8 solid, except for bare ground wire.

I didn't realize that. Now that I think about it, I've only seen up to 10 gauge solid wire. Now I know why.

 

[Jim Port]

I don't see anywhere they mentioned a receptacle! I'm thinking wall oven and a loose connection.

A couple people recommended installing a receptacle and matching it with an appliance cord for the oven. I agree with that recommendation. The connections for the wires on the receptacle and for the cord at the oven are made to connect wires of that size. I know it can be done, but as the issues with the existing connection demonstrate, connecting #8 wires with wire nuts is a questionable practice, especially for solid wires. Other places I looked recommended either a split bolt or a compression lug connectors for making direct wire to wire connections on wires that size.

Nothing wrong with properly sized wire nuts being used on #8 or #6.