New wall oven on 30 amp

[Tom Leahy]

Homeowner put new 40 amp double oven in and was wired to a #10 and 30 amp breaker. Never used both ovens at the same time so never had a problem. Told him he needed #8 and 40 amp breaker. Homeowner had electrician come out and electrician said since kitchen was upstairs, to difficult to run new wire and he should just put in a 35 amp breaker and all would be good. Common sense tells me no, but with electrician saying this, thought I would throw it out to the sparkys for clarification.

[Jeffrey R. Pope]

240.4 Protection of Conductors.

(D) Small Conductors. Unless specifically permitted in 240.4(E) through (G), the overcurrent protection shall not exceed 15 amperes for 14 AWG, 20 amperes for 12 AWG, and 30 amperes for 10 AWG copper; or 15 amperes for 12 AWG and 25 amperes for 10 AWG aluminum and copperclad aluminum after any correction factors for ambient temperature and number of conductors have been applied.

But I am not a "Sparky."

[Jim Port]

Whether it is too difficult or not the proper size circuit using #8 CU should be run. There is no allowance for "too difficult" in the Code. Also, the instructions provided need to be followed.

I agree with Jeff.

[Tom Leahy]

Thanks guys. I knew but with a licensed electrician doing something wrong and being liable for his work threw me into questioning if I was missing something. This was my 15th mock, still learning. Thanks again.

[Sean Fogarty]

What does the paper work or the label on the stove require? If it says 40 amp, tell him to argue with the manufactuer.

[Robert Meier]

Without the rating of the oven it's hard to say for sure if this is an NEC violation or not. But with the information given it sounds as if it violates this code section:

210.19(A)(3) Household Ranges and Cooking Appliances. Branch-circuit conductors supplying household ranges, wall-mounted ovens, counter-mounted cooking units, and other household cooking appliances shall have an ampacity not less than the rating of the branch circuit and not less than the maximum load to be served. For ranges of 8¾ kW or more rating, the minimum branch-circuit rating shall be 40 amperes.