Melted 12-3 wiring

[ishiboo]

It wasn't my intent to start a flame war, so I will speak my piece and move on as some of you have suggested.

When I made my 1st post to this forum, I wasn't asking for help in choosing the correct wire size for my application. I simply asked " I know a loose connection will arc but will a loose connection at the breaker overheat and melt the insulation back?" I wasn't looking for a lecture about using the wrong wire size or a sermon about my house burning down, I was looking for a simple answer to a obvious problem. I should have explained that I didn't have the time to drive (90) minutes to get a 6' piece of 8-3 but I need to get the oven online and I had a piece of 10-3. Was it code, no but you do what you have to do, to survive.

Several of us answered your question.

I'm partially to blame on expecting some of you to have a background in Thermodynamics and explain that where the insulation ends on the copper wire, the insulation is no longer partially airtight. And when you add Heat, Oxygen and Fuel, there will be combustion, or melting in this case because the plastic insulation had not yet reached its combustion point. The fact that no one could answer it besides just an obvious "Yes" indicates that some of you don't have the experience and expertise to offer a detailed explanation.

Or we weren't wasting our time to explain the basics of the simple fact SOMETHING HOT melts SOMETHING PLASTIC next to it. We thought you knew that.

The lack of oxygen/insulation being airtight/etc. have NOTHING to do with it. The loose connection is where the heat is generated, plain and simple. So the insulation closest to it will melt/burn/etc.

You're still clueless with what happened. I guess that's our fault for not spelling it out.

The ends of a wire run or where the insulation has been stretched and therefore thinned out, are the most susceptible to overheating because air can penetrate. When the insulation is stretched thin, more heat leaks out and if the thin point is near a combustible or metal surface, it can either heat or arc possibly causing a fire. Modern Residential and Commercial electrical fires are usually attributed to human error, like driving a staple through the insulation, or improper grounding, thinned or nicked insulation, not having a 12-3 Romex that's pulling 13 amps.

Huh?

Wire WITHOUT insulation is LESS susceptible to overheating BECAUSE it's easier to exchange heat, convection, etc. Insulation on wire is not for heating/cooling/etc. but to prevent conductivity. The arcing had NOTHING to do with the insulation, it happened directly in the breaker's hold down screw, in between the wire and the metal.

This is why knob and tube wiring survives for years until someone blows the cavity/attic/etc. full of insulation - it can no longer dissipate heat.

You're clueless. It doesn't take a "background in thermodynamics" to understand these basic principles.

The rest of the dialogue about Aluminum Appliance whips and the NEC being the All and Powerful OZ just shows that some of you don't have the ability to question why.
It also demonstrates how hypocritical those of you that are Contractors can be.

Rant without any purpose ignored. I still don't believe your whip is aluminum, but identifying metals is likely above your head.

While you're quick to condemn me for using a smaller wire then NEC dictates, I'm sure there's not one Contractor in this Forum that hasn't taken a shortcut by using the wrong size wire in a conduit run or wrapped a splice in a junction box, not twisting the ground wire the correct number of turns in commercial wiring or not even grounding a metal box knowing full well a Building Inspector wouldn't crawl or climb a ladder to check. I've been around Contractors long enough to know it's all about profit and not about principal, and I've yet to see an Electrical Contractor torque anything unless they had to, ie: got caught.

So remember, in John 8:7, it states! "Let any one of you who is without sin be the first to throw a stone."

Enough said. Alpha Mike Foxtrot

Yeah, you've pretty much shown your true colors.

Let it be now known to you as it wasn't before, if you come to an Internet forum and ask a specific question which also reveals you ignorantly created a dangerous situation, and should have hired a professional, people will not only question what you've done but provide their own 2 cents. That's how forums work. People were going to add their input, whether you wanted to hear what a ***** you were or not.

 

[C96]

NEC is the all knowing OZ

That’s funny, and yes, Bosch thinks so as well. That’s why on Page 9 of the ovens Installation Instruction Manual it clearly states under the Wiring Requirements section that:

• Wiring must conform to the National Electrical Code
• The oven must be connected with copper wire only

We have all gone out of our way trying to help you get this problem fixed properly and safely, but for whatever reason, you insist on justifying your incorrect way.

Page 9 also gives you information where you can obtain a copy of the NEC. I highly recommend you do so, especially if you ever plan on doing any electrical work again.

Also, I recommend you read the manual that came with the oven; you obviously haven’t bothered to open it. If you don’t have one, you can download the entire Bosch oven manual for yourself.

Once you have read both the NEC along with your oven manual and fully understand what you have read, only then will you realize what we have been trying to help you with.

Here is a copy of page 9 with the areas of concern highlighted:

 

[joel63]

Several of us answered your question.



Or we weren't wasting our time to explain the basics of the simple fact SOMETHING HOT melts SOMETHING PLASTIC next to it. We thought you knew that.

The lack of oxygen/insulation being airtight/etc. have NOTHING to do with it. The loose connection is where the heat is generated, plain and simple. So the insulation closest to it will melt/burn/etc.

You're still clueless with what happened. I guess that's our fault for not spelling it out.



Huh?

Wire WITHOUT insulation is LESS susceptible to overheating BECAUSE it's easier to exchange heat, convection, etc. Insulation on wire is not for heating/cooling/etc. but to prevent conductivity. The arcing had NOTHING to do with the insulation, it happened directly in the breaker's hold down screw, in between the wire and the metal.

This is why knob and tube wiring survives for years until someone blows the cavity/attic/etc. full of insulation - it can no longer dissipate heat.

You're clueless. It doesn't take a "background in thermodynamics" to understand these basic principles.



Rant without any purpose ignored. I still don't believe your whip is aluminum, but identifying metals is likely above your head.



Yeah, you've pretty much shown your true colors.

Let it be now known to you as it wasn't before, if you come to an Internet forum and ask a specific question which also reveals you ignorantly created a dangerous situation, and should have hired a professional, people will not only question what you've done but provide their own 2 cents. That's how forums work. People were going to add their input, whether you wanted to hear what a ***** you were or not.

ishiboo

I have read many of your posts dealing with electrical topics.


You did a highly competent trying to explain things to the op.


He just can't hear you.

 

[sberry]

I agree there can be some fudge factor,,, with the right wire not one 2 sizes too small. This appliance and connection would have survived 1 too small, it would have worked but would have been fully loaded and that means overloaded where there is the potential for continuous use. So it would have survived one level of dumb.
There is no surprise it first showed up at a connection, I don't see it as some kind of mystery. This is a plus and an argument for large wire on welder circuits, the 6 50 isn't listed for 14 wire anyway and am not sure they are even all listed for 12 ?????? What is a 50A breaker listed for?

 

[PRH44]

FIRE DEPARTMENT PLEASE

 

[Blk88GT]

^^^ lol!

 

[sberry]

The appliance makers are not faultless here and they still assume the installer is qualified which is about half true or half below average as the OP points out. I don't know why Miller still lists the minimum spec to the 210 welders, I spose either way they would have to splain wire size.
Miller has one of the techs do plain language of an 8 wire circuit I think but they are pretty fuzzy and not every engineer understands it. I should realize I cant out think this system though but with the advent of diy a small chapter in lay language couldn't hurt and if I was writing would cross the 14 out and list 12. Lincoln writes theirs different

 

[sberry]

Ifs been a while since I read the details of cooking appliances, seems I have seen tags on input wires with regards to circuit requirements and limits? They list the kv in the manual, would it hurt to list a wire size? An oven with a kva rating of 3.6,,, what cable does it call for?

 

[wyliesdiesels]

Ifs been a while since I read the details of cooking appliances, seems I have seen tags on input wires with regards to circuit requirements and limits? They list the kv in the manual, would it hurt to list a wire size? An oven with a kva rating of 3.6,,, what cable does it call for?

With an oven, the KW and thus the circuit ampacity requirement changes based on the system voltage,(as does any resistance load appliance/device) so it would be more complicated than 'one size wire fits all!'

 

[Forest Road]

Why did the op bother asking for advice? Clearly he isn't listening.

Id love to see the fire inspectors reaction to "my dads generation did it that way" standing next to a burned out foundation.

 

[bsaint]

Now you know why we have the NEC.

30A? You need 10 Awg wire....

I suspect the only reason you got by up to now is because of the voltage drop for the distance of your original run. With the shorter wires...current goes up...wire gets hotter......melts.

Actually....you really need 8 Awg wire and a 40A breaker....

Shorter wires, the current goes down. Slightly. Its why we tell people never to run an electric wheel borrow compressor off an extension cord.

 

[Metal-Marc]

Why did the op bother asking for advice? Clearly he isn't listening.

Id love to see the fire inspectors reaction to "my dads generation did it that way" standing next to a burned out foundation.

So, did OP burned his house down yet?

 

[sberry]

With an oven, the KW and thus the circuit ampacity requirement changes based on the system voltage,(as does any resistance load appliance/device) so it would be more complicated than 'one size wire fits all!'

I guess I should have been more clear, sometimes I assume one could read between the lines a little but I guess not.