11.6 KW range

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flatlander

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Diamond bar, CA , Tempe AZ
I don't think the op was thinking damand factor or load.
I think what it was about how the manufacture can say branch circuit rating of 40 amps from a almost 12 kw range.
I know for the purpose of a load calc you apply a demand factor which will be less
 
LarryFine

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
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Electrical Contractor
Sierra, if you really want to know, install #6 wire, but a 40a breaker. When the range is installed, turn every burner and the oven on to high.

If the 40a breaker trips, replace it with a 50a; if it doesn't, you will know for next time. Let us know if you like my (or rather, your) experiment.
 
Dennis Alwon

Dennis Alwon

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The fact is it would be a very unlikely scenario to have a range going with all the burners, ovens, etc on at the same time. Most new ranges have thermostats in the eyes also which would keep them from coming on at the same time. This is why we have T 220.55
 
infinity

infinity

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flatlander said:
I don't think the op was thinking damand factor or load.
I think what it was about how the manufacture can say branch circuit rating of 40 amps from a almost 12 kw range.
I know for the purpose of a load calc you apply a demand factor which will be less
Click to expand...


You are permitted to calculate the size of a branch circuit for an electric range according to Table 220.55. Look at note #4 to the table.

One appliance in column C not over 12 kw is permitted to be calculated at a maximum demand of 8 kw.

8000/240 = 33.33 amps
 
augie47

augie47

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infinity said:
You are permitted to calculate the size of a branch circuit for an electric range according to Table 220.55. Look at note #4 to the table.

One appliance in column C not over 12 kw is permitted to be calculated at a maximum demand of 8 kw.

8000/240 = 33.33 amps
Click to expand...

Rob,
I have no diagreement on the 40 amp circuit. But your post brings up an old discussion.
Can you use a Art 220 calculation to size an Art 210 branch circuit ?
 
infinity

infinity

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augie47 said:
Rob,
I have no diagreement on the 40 amp circuit. But your post brings up an old discussion.
Can you use a Art 220 calculation to size an Art 210 branch circuit ?
Click to expand...

IMO according to note #4 you can:

Branch Circuit Load. It shall be permitted to calculate the branch circuit load for one range accordance with 220.55.

It would seem rather silly to be allowed to calculate the load using this table and then not be able to actually apply that calculation to the branch circuit supplying the load.
 
Sierrasparky

Sierrasparky

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USA
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Electrician ,contractor
I don't know if I am confuse or you folks are.
I was reffering to the fact that the range load is 11.6 KW which is almost 50 amps.
You all are talking demand and such.
I am referring to circuit ampacity.
I don't belive a 50 amp range should be on a 40 amp circuit.
Regardless on any reduction due to demand load factor corrections.
 
Sierrasparky

Sierrasparky

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Location
USA
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Electrician ,contractor
got it.
So when my competitor told my customer he had to change out the 50 amp breaker to a 40 amp one and no where did it say max breaker 50 amp.
This guy was probably wrong.
I did not install the 50 it was in a home built in the late 70's or early 80's.
The breaker was a FPE and I bet he got a nice profit on a simple job.
 
Dennis Alwon

Dennis Alwon

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Sierrasparky said:
got it.
So when my competitor told my customer he had to change out the 50 amp breaker to a 40 amp one and no where did it say max breaker 50 amp.
This guy was probably wrong.
I did not install the 50 it was in a home built in the late 70's or early 80's.
The breaker was a FPE and I bet he got a nice profit on a simple job.
Click to expand...

Well, it really would depend on what size and type of wire was pulled to the range. If, for instance you ran 8-3 NM then you would be restricted to the 60C column and a 50 amp breaker would be a violation. If you ran #6 then installing a 50 amp breaker would be code compliant
 
Sierrasparky

Sierrasparky

Senior Member
Location
USA
Occupation
Electrician ,contractor
Dennis Alwon said:
Well, it really would depend on what size and type of wire was pulled to the range. If, for instance you ran 8-3 NM then you would be restricted to the 60C column and a 50 amp breaker would be a violation. If you ran #6 then installing a 50 amp breaker would be code compliant
Click to expand...

I realize that I would never place a breaker greater than the wire can handle by code. ( nor remove one)
I just was concerned because the competitor charged to replace a breaker I felt was un-necessary. There was no requirement by the manufacture to have a max breaker at 40 amps. nor was the wire size too small.
 
G

gndrod

Senior Member
Location
Ca and Wa
iwire said:
:grin:

I think you may not be catching what they are saying.




You can believe that but the NEC allows it and it will not burn down the house.:)
Click to expand...

Hi Bob,

I realize that the 220.55 vs. the 210.19 discussion occurs quite a lot and I can remember this same debate a couple of years ago. At that time, an issue came up to where an AHJ red tagged the using the 40 Amp #8 awg cable BC for range hookups. It was a hard lesson in how the NEC can be very misleading should 220.55 be used to size conductors without checking with the AHJ and taking a close look at using load calculations.

The code violation involved multi-family dwellings and the Table 220.55 was used for Demand Factoring the range sizing. Would you believe the AHJ stated T220.55 could not be used for the Optional Method 220.84, thus sizing came under the Art. 210.19 requirement. The Optonal Method for Multi-family is calculated under the 45% or less DF from T220.84 three or more Multi-Family Dwelling units.

The ranges DF is applied as the full NPR rating. Would there be another way around this to use T220.55 in this case other than a separate house circuit laundry facility? rbj
 
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gndrod

Senior Member
Location
Ca and Wa
infinity said:
You are permitted to calculate the size of a branch circuit for an electric range according to Table 220.55. Look at note #4 to the table.

One appliance in column C not over 12 kw is permitted to be calculated at a maximum demand of 8 kw.

8000/240 = 33.33 amps
Click to expand...

T220.55 may not be used with Optional Calcs. [220.82] [220.84] See above post #18 to Bob.
 
glene77is

glene77is

Senior Member
Location
Memphis, TN
Dennis Alwon said:
The fact is it would be a very unlikely scenario to have a range going with all the burners, ovens, etc on at the same time. Most new ranges have thermostats in the eyes also which would keep them from coming on at the same time. This is why we have T 220.55
Click to expand...

Dennis,
You are differentiating between

(1) "Calculating Diversity Loads"
to determine the Service Size
and
(2) "Calculating Ampacity of conductors"
to determine proper wire size.

Right?
If so, I agree with you.
:)
 
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