Jim W in Tampa
Senior Member
- Location
- Tampa Florida
What do you pay per kw ?
40A or 50A Circuit
- Thread starter ivsenroute
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What do you pay per kw ?
kbsparky
Senior Member
- Location
- Delmarva, USA
Your turkey would be burned to a crisp if the oven element remained on for the whole duration.
Just because the oven is on, does not mean that the actual element is on the entire time. It cycles on and off to maintain the proper cooking temperature.
ivsenroute
Senior Member
- Location
- Florida
Ultimately, it does not appear as though all four burners and the elements would be on at the same time for 3 hours therefore it is unlikely that a range would be considered continuous for normal use. Heating the house (for which it is not designed or listed) does not count.
With that being said, a 40A circuit would be the code minimum circuit.
I know that many EC's would put in a 50A circuit just to play it safe and give the homeowner more options if they replace the unit in the future.
It also looks as though the 40A circuit crowd is the majority although this is not a blowout which shows how differently we are.
Personally, I automatically put in at least a 50A circuit unless it needs to be bigger. The code says 40 but that of course is the minimum allowed thanks to the derating of the NEC table.
With that being said, a 40A circuit would be the code minimum circuit.
I know that many EC's would put in a 50A circuit just to play it safe and give the homeowner more options if they replace the unit in the future.
It also looks as though the 40A circuit crowd is the majority although this is not a blowout which shows how differently we are.
Personally, I automatically put in at least a 50A circuit unless it needs to be bigger. The code says 40 but that of course is the minimum allowed thanks to the derating of the NEC table.
It seems that the manufactures instructions are going to be saying 50 amp more often then 40 amp.
I know that article 220 is "Branch circuit, Feeders, and Service Calculations" but I read it that it is telling you what to use as an Ampere rating to add to the over all rating for the service or feeder, But not for sizing the final branch circuit to the range ( seems counter intuitive ) when I look at the name plate KW rating on the unit I divide it by 240 volts and that is the circuit size I use for the wire and breaker to the range.
ivsenroute
Senior Member
- Location
- Florida
You are making a good point.
We have been referencing 220.55 which is for feeder and service load calculations, not branch circuit ratings.
If we tip toe back to 210.19 dealing with branch circuit ratings, it clearly states that the conductors shall not have a rating less than the load to be served. It further states that ranges 8.75kW or more must have a minimum of a 40A branch circuit.
So when sizing the branch circuit, do we strictly go off of the data plate?
If we are suppose to derate the branch circuit in Table 220.55, don't you think we would be directed to do so in the 210 section?
We have been referencing 220.55 which is for feeder and service load calculations, not branch circuit ratings.
If we tip toe back to 210.19 dealing with branch circuit ratings, it clearly states that the conductors shall not have a rating less than the load to be served. It further states that ranges 8.75kW or more must have a minimum of a 40A branch circuit.
So when sizing the branch circuit, do we strictly go off of the data plate?
If we are suppose to derate the branch circuit in Table 220.55, don't you think we would be directed to do so in the 210 section?
This is exactly the reasoning I am using. I don't see where the rational for derating the final branch circuit is coming from, 210.19 (A)(1) says the opposite of this.
ivsenroute
Senior Member
- Location
- Florida
Good point, that was reworded for the 2005 code. Don't know what it says in the 08 since we are not there yet.
I still see that as a service load calculation issue. Not a branch circuit sizing table.
hardworkingstiff
Senior Member
- Location
- Wilmington, NC
Does anyone have an issue with putting a 50-amp receptacle on a 40-amp circuit?
210.21 B 3 (2005) oops, no prob
Last edited:
- Location
- New Jersey
- Occupation
- Journeyman Electrician
I don't disagree. I have never calculated branch circuiting for ranges based on table 220.55 either, so the first few posts in this thread threw me off. But it seems like an argument could be made that table 220.55 could be used this way.
Article 220 according to its title, "Branch Circuit, Feeder, and Service Calculations", seems to indicate more than just calculating service conductor ratings.
M. D.
Senior Member
I agree with Pierre this is how I would do it ,...the major fraction is treated as 1kw.
Just curious, how do you determine that article 220.5 is even allowed for determining the size of conductors to range ? I just don't read it that way myself.
aftershock
Senior Member
- Location
- Memphis, TN
I would install an 8/3 with a ground. Install a 4 wire 50 amp recep and a 4 wire 50 amp pigtail. Since it is a 50 amp circuit rated for 50 amps, I would place a 50 amp breaker for the overcurent device.
- Location
- Massachusetts
That would be a violation, 8/3 NM and now 8/3 SE are both rated 40 amps, you can not use a 50 amp breaker.
aftershock
Senior Member
- Location
- Memphis, TN
I swear I have not seen you in this post until I replied. I understand what you are saying. Keep in mind, I am using the 2002 code and I am waiting until we adopt 2008. I have kept telling my boss about what I have read here but it does not seem to phase him. My boss is 80 yrs old.
As far as I am concerned, our local AHJ have allowed us to wire electrical but at the same time they have allowed us to do so that violates code. Example would be using romex in conduit.
I have argued quite a bit with my boss to get a fire under our local AHJ's rears. I dont like it that we adopt a part of a code book and I dont like it that I cannot obtain a full version of the county codes.
I want it to where I have a book I can go by to do my thing,, but no, I can only rely half way on my book and can only learn anything when I get turned down.
That stinks on the inspectors side. I would think if they don't have a formal written amendment to the code then there is no change from what ever code cycle they are using 02' 05' or 08' If you go by NEC you will not go wrong as it gives you more back up then BillyBob the inspector saying "well thats the way I want it".
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