Wiring question

[G-force]

Happy Memorial Day everyone!

I'm trying to wire in an electric oven to use the same wall plug as my welder in the shop. The harness coming out of the oven uses puny 14-16 gauge wire as seen in the picture.

My wall plug is of the three prong variety. Here is the guts to the plug I use with my welder.

And heres the wall socket...

Given what I'm working with, what is the best way to wire this to a plug? Thanks

 

[pattenp]

You can't. First thing, what size circuit does the instructions say to use for the oven? Second, it appears the oven takes 120/240V and the outlet you have is only 240V.

 

[mds5951]

Is this recepticle coming from a subfeed? Or the main? Also how many amps does the oven require? And how many amps is the recepticle?

4 to 3 wire stove conversions are very common as many old houses did not require a grounded (4 wire) 220 outlet

 

[G-force]

Its from a main. Not sure on amps but i'm thinking 50 IIRC.

 

[930dreamer]

I added a neutral wire to my welding circuit to test the free oven I found.

 

[mds5951]

Hmm I actually retract my last statement. You're gonna have to pull a neutral to get it to work. There are ways to potentially make it work... But they are not safe and I won't go over that here.

 

[mds5951]

I will add though that if you look in your manual there may be instruction to bond the ground to neutral in the back of the oven

 

[sberry]

It needs a bonded neutral for 3 wire, will work if its from a main panel but not code legal anymore and it must be limited to 30A or less with 14 wire.

 

[mds5951]

Depending on when it was built he may be grandfathered in... I doubt this is the case tho considering it looks relatively new

 

[Aceman]

That oven looks tiny. Run a separate circuit for it.

 

[G-force]

This is for powder coating in my barn/shop. I will always be present when in use and never leaved it plugged in. I plan on running it 3 wire. If it's a 50a circuit and a 30a oven. What are the risks?

 

[Ryf]

First and best option, wire a box for the job. honestly for what you will have in plugs unless this is impossible/farther from the box than is reasonable it will likely cost the same since you dont need a plug just a box to wire into.

I would buy a welder extension cord/replacement power cord. wire that in place of the MC wire, which will be a nuisance to deal with imo and clean up the install. what you have there is solid wire, not intended for plugging in and unplugging, will give you problems eventually.

to see if it will work, do this first, open up your panel, if your welder circuit is attached to two hots and common and not ground, and the wire has insulation on all the wires hooked to the outlet you can basically skip the ground, is this less safe, yep, is it done all the time, yep. if you dont have insulation on the wire not on a breaker, OR its grounded not common, your asking for problems and need to wire a box for your oven. NONE of this is considered the "right way" and even though 99% of the time it works out fine, its your responsibility to know your safe.

about wire size, my brother in laws lincoln 180c mig has 12 gauge, at most, plugs into a big 50amp plug. my hobart 190 has a bigger wire 10 gauge going to its plug, but they both weld the same, the wire is sized for its draw, so undersizing the wire is AOK on the device end, but not on the installed outlet side.

 

[G-force]

The box is 75 feet away and running a new line would either need to go up over the 2nd story of the barn with the existing welder circuit or it would need to go through two walls so for ease of install I would really like to be able to use the existing circuit. I know not the best way, but I may use it only a handfull of times a year.

I did make about a 30' extension cord for my welder. (pictured in the opened plug above). I will check the box to see if it has a common or a ground ran to the box. If it is ground, do I connect the bare wire and white wire together to the ground from the box? What if it is a common>

The instruction manual does describe wiring this for a 3 wire lead if necessary, but I was wondering if the higher amperage (50a) at the wall will damage the oven if it is only rated for 30a.

 

[pattenp]

If the oven is specified to be wired on a 30 amp circuit then putting it on a 50 amp circuit will create the potential that the stove wiring could be toasted in the event of an overload before the 50A breaker would trip. Also if the the specs call for a separate neutral then bonding the neutral and ground in the oven to use the outlet ground as a neutral is just a bad idea. You run the risk of energizing the oven case and causing a shock hazard.

 

[G-force]

It's interesting that it lists 3 wire neutral/ground bond as a hookup option in the instruction manual if the 4 wire option is not present in the home. This oven is only about 10 years old.

 

[pattenp]

As long as the oven instructions list and show how the neutral ground bond is to be done in the oven then it's okay. I was thinking by looking at the wire in the picture that it needed a separate neutral and was to be wired as 4 wire. The only concern I'd have is be putting it on a 50A circuit. But if it's going to be cord and plug connection and you say it won't be left unattended then go for it.

It's interesting that it lists 3 wire neutral/ground bond as a hookup option in the instruction manual if the 4 wire option is not present in the home. This oven is only about 10 years old.

 

[nehog]

If the oven is specified to be wired on a 30 amp circuit then putting it on a 50 amp circuit will create the potential that the stove wiring could be toasted in the event of an overload before the 50A breaker would trip. ...

Breakers are for protection of the wiring, not the device attached. One should never rely on a breaker to protect the load device.

 

[G-force]

Here's the 3 wire paragraph in the instruction manual

 

[pattenp]

And one shouldn't wire a device on a 50A circuit that is stated by the manufacturer to be put on a 30A circuit . Plus you not telling me anything I don't know.

Breakers are for protection of the wiring, not the device attached. One should never rely on a breaker to protect the load device.

 

[G-force]

Well me welder does run on 30a come to find out so sll should be good.

 

[pattenp]

You're good. I have a tendency to stuck on technicalities.

Well me welder does run on 30a come to find out so sll should be good.

 

[Aceman]

I'll mention a couple things:

First, to be able to bond the neutral/ground together in the oven you have to meet the requirements of the 250.140 exception.

Second, you need to meet manufacturer requirements on breaker sizing as well.

 

[pattenp]

G-force, was that 50A circuit installed as a welder only circuit? The reason I ask is the circuit wire may be undersized because of being dedicated as a welder circuit. You should verify what the wire size is. This is where things run a muck of code because of trying to use a specialized circuit for two different purposes.