Range Wire Sizing

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iwire

Moderator
Staff member
Location
Massachusetts
Mike what do we care what the 'DOI' has to say?

Outside of their jurisdiction they provide no more of an official interpretation of the NEC then you or I do.

That at least explains why you feel like you do, it is a local thing and if that is how your AHJ sees it than that is how it is in your area:)



210.23 Permissible Loads.

In no case shall the load exceed the branch-circuit ampere rating. An individual branch circuit shall be permitted to supply any load for which it is rated. A branch circuit supplying two or more outlets or receptacles shall supply only the loads specified according to its size as specified in 210.23(A) through (D) and as summarized in 210.24 and Table 210.24.

Under the NEC you can not purposly connect a 50 amp range (after demand factors) to a 40 amp branch circuit. :)
 

iwire

Moderator
Staff member
Location
Massachusetts
jwelectric said:
At least I found someone that would address the last sentence of 210.19(A)(3) and nothing else something I couldn't get in here.
:)

You may feel that way but it is patently untrue.

We all addressed it, the problem is it was not what you wanted to hear.
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
jwelectric said:
. . . for ranges of 8? kW or more rating, the minimum branch-circuit rating shall be 40 amperes.
Okay, we agree, that's what it says. The minimum. Never less than 40 amperes. 40 amperes or more. 40 amperes at the least.

What it does NOT say is "...and no more." What it does NOT say is "all range branch circuits shall be 40 amperes." What it does NOT say is ". . . for ranges of 8? kW or more rating, the branch-circuit rating shall not be required to be more than 40 amperes."

Remember, we haven't picked on you for that other thread . . . yet.
 

davedottcom

Senior Member
For ranges of 8? kW or more rating, the minimum branch-circuit rating shall be 40 amperes

This sentence (Exactly as it is written) declares that the circuit rating shall not be less then 40 amps even if the load is less than 40 amps.

It would be easier to understand if it said .... For ranges with a load of 36.45 to 39.99 amp rating, the minimum branch circuit rating shall be 40 amperes.


But 210.19(A)(3) already does declare that and there is no reason to change the wording except to make it easier to comprehend.

Dave
 

Cavie

Senior Member
Location
SW Florida
I'm probibly gonna get beat on but here goes. My opinion, for what it is worth, is that 220.55 is used for FEEDER and SERVICE CALCULATIONS as it is Part III of that section. and is not intended to be used for branch circuit calculations. 210.19 A 3 Household Ranges and Cooking Appliances. states very simply "Not less than the maximun load to be served". Let the flogging begin.
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
Cavie said:
I'm probibly gonna get beat on but here goes. My opinion, for what it is worth, is that 220.55 is used for FEEDER and SERVICE CALCULATIONS as it is Part III of that section. and is not intended to be used for branch circuit calculations.
We have the same argument about whether the NEC specifiec receptacles-per-circuit quantities.
 

Gmack

Banned
Location
Michigan
Cavie, this is from the 2005 NEC Handbook. Take note of "branch circuit loads" contained therein.

I. General
220.1 Scope
This article provides requirements for calculating branch-circuit, feeder, and service loads. Part I provides for general requirements for calculation methods. Part II provides calculation methods for branch circuit loads. Parts III and IV provide calculation methods for feeders and services. Part V provides calculation methods for farms.

Article 220 contains requirements for calculating branch-circuit, feeder, and service loads. Revised for the 2005 Code to provide better organization of the calculation rules, Article 220 now contains a new Part I with general requirements, and Parts II through V contain the calculation requirements for branch circuits, feeders, services, and farm loads. The organization chart of the revised Article 220 is shown in Figure 220.1. Although Article 220 does not contain the requirements for determining the minimum number of branch circuits, the loads calculated in accordance with this article are used in conjunction with the rules of 210.11 to determine how many branch circuits are needed at a premises. A global change in the 2005 Code is use of the word calculate (or a derivative thereof) consistently in all load calculation requirements. Table 220.3, which is new in the 2005 Code, identifies other articles and sections with load calculation requirements.

FPN: See Figure 220.1 for information on the organization of Article 220.
 

Cavie

Senior Member
Location
SW Florida
Gmac. I have read what you stated. But Table 220.55 falls under Part III "FEEDERS AND SERVICE LOAD CALCULATIONS". and is not intended for use to determine the wire and breaker size for a range. If it was, there would be no need for 210.19 A 3. Do we just ignore this article? I do wish to understand as this very topic came up today in one of my inspections. A 40 unit condo no less.
 

jwelectric

Senior Member
Location
North Carolina
Cavie said:
Gmac. I have read what you stated. But Table 220.55 falls under Part III "FEEDERS AND SERVICE LOAD CALCULATIONS". and is not intended for use to determine the wire and breaker size for a range. If it was, there would be no need for 210.19 A 3. Do we just ignore this article? I do wish to understand as this very topic came up today in one of my inspections. A 40 unit condo no less.

Part II
Branch Circuit Load Calculations
220.18 Maximum Loads.
The total load shall not exceed the rating of the branch circuit, and it shall not exceed the maximum loads specified in 220.18(A) through (C) under the conditions specified therein.
(C) Range Loads. It shall be permissible to apply demand factors for range loads in accordance with Table 220.55, including Note 4.

This allows Table 220.55 to be used to calculate branch circuits for ranges.

:)
 

jwelectric

Senior Member
Location
North Carolina
220.18 (C) Range Loads. It shall be permissible to apply demand factors for range loads in accordance with Table 220.55, including Note 4.

220.55 Electric Ranges and Other Cooking Appliances ? Dwelling Unit(s).
The load for household electric ranges, wall-mounted ovens, counter-mounted cooking units, and other household cooking appliances individually rated in excess of 1? kW shall be permitted to be calculated in accordance with Table 220.55. Kilovolt-amperes (kVA) shall be considered equivalent to kilowatts (kW) for loads calculated under this section.

Table 220.55 Note 4. Branch-Circuit Load. It shall be permissible to calculate the branch-circuit load for one range in accordance with Table 220.55. The branch-circuit load for one wall-mounted oven or one counter-mounted cooking unit shall be the nameplate rating of the appliance. The branch-circuit load for a counter-mounted cooking unit and not more than two wall-mounted ovens, all supplied from a single branch circuit and located in the same room, shall be calculated by adding the nameplate rating of the individual appliances and treating this total as equivalent to one range.

But let?s not forget what we are told in 210.19(A)(3)

I will be gone for the Easter holidays so when I return home I am expecting this thread to be close to 300. Let?s keep up the debate and no one should relinquish their side of the debate.

Happy egg hunting to all my friends but let?s not forget what this holiday represents.
 

George Stolz

Moderator
Staff member
Location
Windsor, CO NEC: 2017
Occupation
Service Manager
hardworkingstiff said:
Has this turned into a game?
Yeah, I'm pretty sure that Mike held out on the "conductors versus rating" bit to extend the thread.

It still doesn't hold water, thanks to the first sentence of 210.19(A)(3). :lol:

I, for one, feel gypped. :D
 
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