Newbie oven questions (electrical)

[kcdonahue]

Hey Guys,

Couple of newb questions about wiring up an oven. I just got my hobby gun and a bunch of powder and I’m itching to get started…. Here’s my question: I got a free GE Hotpoint electric oven off of the local Craigslist site and I have removed all of the range elements and the broiler element since I will not need them and it will lower the amount of power I will need. Next I removed the bake element and measured its resistance (23 ohms) so I could try to figure out how many amps the oven will draw when only using the bottom/bake element. (The element is labeled as 240/2565 and 208/1940 watts.) When I do the math with ohms law (from this website: http://www.angelfire.com/pa/baconbacon/page2.html) it tells me that 23 ohms @ 240 volts the element will draw about 10.5 amps… Is this correct? I’m kind of new at this and trying to follow earlier posts about what type of wire and breakers I will need.
Next question, would it be okay to run this oven on a 20 amp breaker that is on 60 feet of 12/2 wire that is already installed in the garage for my compressor? I’m thinking that I will need to upgrade the wire to a 10gauge too feel safe.
If it is possible to run the oven on the 20 amp breaker I will also have to buy the same 20 amp plug for the oven like the one on my compressor and will have to unplug the compressor when I want to use the oven but since I have a 30 gallon tank and only small bits to coat I think it will last long enough to get by….
Any thoughts or comments on what I’m trying to do? I just wanted to check here on the forum before I start doing anything…

Thanks,

KC in MD

[mikekozura]

I think I got this stright you removed all the elements but one and it draws 10.5 amps. So yes the 12awg wire and 20amp breaker will be fine. Thats a h@ll of an idea, I think. The oven is going to work as normal no wiring no buying nothing just disconect the other stuff and turn it on just like you were making a pizza. The only reason a range has the 50amp stuff is for when you have everything running.

[jrow]

kcdonahue,

The only questions I would have is your oven going to heat up quickly enough with the one 2565 watt element that you are not going to waste power, and money? The quicker that oven heats up the quicker your powder will cure. Don't forget an IR thermometer!

Are you sure your wire is 12/2, or is it 12/3 with ground? You need at least three wires to run 230V!

John

[kcdonahue]

Mike and John,

Thanks for the replies! Regarding the oven and the 2500 watt element... I have yet to attempt to powder coat anything so I have no clue how long it will take to get up to temperature. The oven is a standard household 30 inch job to get me started. Luckily I have a few IR thermometers laying around from one of my old jobs.... Now to find some 9 volt batteries for them....

The wire is 12/2 with a ground... at least thats what I remember from when I installed it.

Thanks,

KC

[mikekozura]

Originally Posted by jrow

kcdonahue,

The only questions I would have is your oven going to heat up quickly enough with the one 2565 watt element that you are not going to waste power, and money? The quicker that oven heats up the quicker your powder will cure. Don't forget an IR thermometer!

Are you sure your wire is 12/2, or is it 12/3 with ground? You need at least three wires to run 230V!

John

Good point John

You really should use 12/3 BUT you can get away with the 12/2 useing the white for a power and the bare ground for both the return and the ground, your just pulling 10 or so amps. From What I think I read your already wirered to the plug for the compressor you just need to make a pigtail for the oven. 12awg is good for 20amps

What a minuite here are you sure the compressor is 220v??

[kcdonahue]

Mike,

The compressor is wired up like you mentioned black and white wire to each tab on the 20A breaker and the bare ground to the ground bar in the breaker panel (which then connects to the ground tab on the receptacle). I wired this up a few years ago and the wire is what was recommended at the time.

Do you gentlemen feel I should upgrade my wiring? The 20 amp receptacle doesn’t have a provision for a Neutral wire, just a green ground screw.

Thanks for the help and comments!


KC

[mikekozura]

It may or may not be up to code today. But it will work fine. Just make sure when you make the pigtail for the oven that it's grounded from the oven all the way back to the ground bare in the panel. My first pc oven was a house oven that I rigged up with no ground or nutral wow go head grap the door handle with out gloves, go head, I dare ya. That used to feel good. Zap LOL And with the gun in your other hand really sucked. That time if I had false teeth they would have fallen out.

[jrow]

kcdonahue,

I would very definitely change the wire. It sounds like you have used 120V wire! The 220V wire should have 3 wires and a ground. Check your main breaker box and see if there is a ground buss bar and a neutral buss bar. Some of the old breaker boxes only have one buss bar that the common and the ground are connected to.
I would buy a 220V switch box. Wire your 220V to it and then run pigtails to your compressor and oven. Check the amperage draw on your compressor and spec the wire to run your compressor and your oven together. Also include in your figuring the extra heating element if your oven doesn't heat up like you want. You may need to change your breaker also. 220V is nothing to mess with it will fry you real good. A good hardware or an electrical equipment supplier will be able to help you with your selections.
Let us know how you make out.

John

[Banditperformance]

jrow is correct about the type of wire. For 220, you need 3 wire, to be compliant to the electrical Code. It has a black, white, and a red wire. As well as a bare ground wire. Red and black are 220. Red to white, and Black to white are both 110v, but 220 between black and Red. If you do not need a neutral on your 220V line, you can run the 12/2, but color the white wire with red tape or something. It's just a precausionary thing, so that you, or anyone else in the future, doen't think the wire is 110 and grab the white wire thinking it's a neutral. They will get a suprise LOL

[kcdonahue]

Thanks Guys,

I remember having a lot of questions when I wired up my compressor a while back. When I looked in my breaker panel a majority of the wiring has both the neutral (white) and the bare ground connected together and it confused the hell out of me... To clarify there are two buss rails one on each side of the breakers but have both white wires and the bare grounds connected together.

To finish getting my compressor wired up, I ended up enlisting the help of my father in law since he is a union electrician and I used what he recommended (and the key here is probably 12/2 is what he had lying around). I never really expected to be running an oven in the garage at the time....

I will likely upgrade the wire here soon once I figure out what my compressor really draws (old craftsman peak 3hp when the planets align just right... ,I’ll have to dig around for the paperwork but I remember that it draws around 10 amps or so…)

My next question for the forum is… once I figure out what gauge wire I need and scrounge the cash to do it what do I do with the neutral and ground wires? I will call the father in law to check but do you think I should follow the wiring in the rest of the house where the neutral and the grounds are connected to the same buss strips on the panel?

Hope my ramblings make sense…


Thanks,

KC