The one thing that I have learned from this thread is that if some of can not explain a section of the code you will go to a different section or article to find an answer such as the following;
RUWired wrote
Mike,When ever you are installing a range that is 8 3/4kw or larger,The absolute minimum circuit allowed is 40amps.If your installing a range less than 8 3/4kw you can use column's a&b for the circuit size.As soon as you go bigger,the minimum circuit starts with a 40a circuit.If the name plate rating or the calculated demand rating requires a larger circuit,then you must go with whatever is higher.But you have to start with a 40a circuit.
Rick
At least he is recognizes the minimum circuit although he is jumping to 220.55 and adding to the sentence,
hardworkingstiff wrote
The maximum load determines the minimum circuit unless it is less than 9.6 KW (since that is the maximum load for the minimum 40-amp required circuit that we are discussing).
That is what the section of codes says that you are quoting.
Now I still can not see this 9.6 anywhere in that sentence. Is this something that you are adding on your own?
Gmack wrote
I would then echo, how can this man "teach"
Well my friend I helped write the books that the state of North Carolina uses to teach its electrical inspectors. In the same group of people was the Chief Electrical Inspector for the State and his Chief Assistant as well as 15 other Department Heads.
When all else fails go to the horses mouth.
Maytag Maytag? Electric 30 in. Double-Oven Range
.When using a power supply cord use only a supply cord with closed loop terminals rated either 240 volts, 40 amps or 240 volts, 50 amps that is marked for use with nominal 1-3/8? (34.94 mm) diameter connection opening and marked for ranges.
http://www.homedepot.com/cmc_upload/HDUS/EN_US/asset/pdfs/cbb94cdd-a47f-409d-a5c9-624649253676.pdf
Amana 30" 5.22 Cu. Ft. Freestanding Self-Clean Electric Range w/ Easy-Use Convection & Warming Drawer
ONLY a power supply cord rated at 240 volts minimum, 40 amperes or 50 amperes power supply cord that is marked for use with nominal 1 3/8_ (34.93 mm) diameter connection opening, with closed loop terminals and marked for use with ranges shall be used.
http://www.ajmadison.com/cgi-bin/ajmadison/AER5845QA.html
GE 30" CleanDesign Freestanding Electric Range w/ PreciseAir Convection System & Hidden Bake Oven Interior
A range cord rated at 40 amps with 125/250 minimum volt range is required.
A 50 amp range cord is not recommended but if used, it should be marked for use with nominal 13⁄8″ diameter connection openings.
http://www.ajmadison.com/cgi-bin/ajmadison/JB910.html
Each one of these range manufactures recommends a minimum 40 amp circuit for these large and expensive ranges. One of the manufactures of these large ranges does not recommend a 50 amp circuit but will allow one.
I suppose that I could inject section 110.3(B) but I won?t do this I will still ask all you experts to explain what is meant by [8? kW or more rating,]
I am not asking for information from any other part of the code just only this short sentence.
Now to address the question asked by Gmack
Gmack wrote
Can we wire this same 21kW setup with a minimum 40A?
If I was an electrical inspector inspecting a job where you had installed a 21kw range on a 40 ampere circuit I could not turn you down due to the last sentence in 210.19(A)(3)
With the same breath I would not accept a rejection for this installation with out a written amendment.
