Oven wiring question

[tomco2000]

My single oven went out and the wife wants a double oven with one conventional and one convection oven. The current oven is on a dedicated circuit with #10 wire and a 30 amp breaker. There is no practial way to change the existing wiring.

The oven web site says the double oven needs to have #8 wire and a 40 amp breaker. The maximum load stated is 8000 W. I have been told (by amateur electricians) that unless I have both ovens on at the same time on high heat, I could run the ovens with no problems with the existing wire and breaker. They believe there is a big enough cushion built in to allow this operation.

I would appreciate any thoughts on this.

[Goedjn]

Follow the installation instructions for that particular oven. You can probably get away with doing it wrong, as long as you only use one oven at a time, but it will still be wrong.

[tomco2000]

I have a two story house and the wiring run betweens the floors. This is why I said it is impratical to change.

[Rick]

existing

Might work, but what are the conditions that make changing the wire impractical? You would be surprised at what an experienced electrician can do...

[Joseph Meehan]

Might work, but it would not be code. I might add that if you had a fire and the insurance company noticed it (the fire department is likely to notice it) you would likely find you have no insurance. This would likely be true even IF that was not the direct cause.

In short, don't do it. I suspect the "There is no practial way to change the existing wiring." is not exactly true and a professional would find a practical way of doing it. Sometimes they are nothing short of amazing.

[gfretwell]

Keep looking at ovens, you might find one that is physically interlocked from both being on at the same time.

[Edwin Pawlowski]

It would not be to code. Sooner or later, both ovens will be on. Why have them if you can't use them. If you ever sell the house, the new owner may not take the precautions you do. If you do use both ovens eventually it will pop the breaker. You may not notice that until you go to take dinner out and find it did not cook. You have the potential to pull more amps than the wire is rated for. Not a safe condition, especially since ovens tend to stay on for an hour or three at a time drawing current on that wire.

It may be easier than you think to do it right. Call an electrician and ask him to take a look a quote it. A real one, not the amateurs you have asked.

I would not do it in my house, nor would I ever recommend anyone else do so.

[Rick]

existing

built in

precautions you

cook.

How so? The breaker is sized for the wire. On a typical branch circuit with many outlets you certainly have the potential to draw more than the wire is rated for-that's what the breaker is for.

Not a

[Edwin Pawlowski]

Key word POTENTIAL

The wire is rated for 30 amps, but the ovens can pull 33. Will the breaker take care of that? Some breakers can tolerate a little overage for a period of time. Is every breaker perfect? Do you want to take that chance? Wire and breakers are supposed to be sized at 80% actual use, not 110%.

Look at the statistic. Most house fires caused by faulty wiring are where something has run for a long period of time. Plug in a 5 hp motor and you blow the breaker or fuse. No serious damage done and you find the problem and fix it. Plug in that space heater and let it run for a few hours, then you have the problem. The heat is building over time.

As you point out, a branch circuit is sized for the wire, but has the potential for many connections. Usually, those connections are not running all the time.The purpose if a double oven is to use both at the same time.

[Rick]

Heh-I've seen some "real" ones that are worse than amateurish in their work...

But he needs to find one that's experienced in remodel work more than new construction. A few fish tapes, some pull rope, lube, and a great sense of direction can make short work of it...

[Edwin Pawlowski]

Some electricians run into this and solve it all the time. In this case, it may even be easier than running new since the old wire may be able to pull the new wire through.

[Joseph Meehan]

Impractical for you. Not likely so for the professional. They get paid for knowing how to do what you can't.

[Rick]

hours, then

Agreed-in no way am I suggesting the existing circuit should be used. It needs to be rewired. My point was that a normal residential branch circuit also has the POTENTIAL for being overloaded much higher than the circuit is rated for (other kitchen appliances for instance)

[Rick]

branch

But is obviously protected by the breaker. And they are not normally loaded for an extended period.

Done....

[Edwin Pawlowski]

They why would you want to own it?

[Tim Fischer]

OK, maybe this is an incredibly stupid question but:

What's the point of having a double-oven if you only can use one at a time?

-Tim

[tomco2000]

I have a master electrician (licensed, insured & bonded) coming out today to take a look. Thanks again for all the help!

(If anyone is interested, I'll let you know how it turns out)

[gfretwell]

different kind of oven?

[Tim Fischer]

OK, I know of standard, convection, and microwave. I'm assuming we're not talking about a microwave, and AFAIK a convection can operate as a standard oven. I still don't see the need for two if you can't use both...

-Tim

[tomco2000]

Thanks again to those who offered advice and help. I went with a pr and it set me back $350.00 but the right size wire and breaker is in. They were creative in running the wire but everything came out o.k.

Now I just have to wait on Sears. My oven is 7 days past promise delivery date, but they have assured me (again) that it will be i tomorrow

-- tomco200

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