Range Wire Sizing
- Thread starter jeff43222
- Start date
- Status
Cavie
Senior Member
- Location
- SW Florida
Ok, it's been 10 pages and 140 posts. Everyone has danced around the question. Now I'm gonna ask the question one more time. What do you do with 210.19 A (3)?? Just eggnore it??? It has no exceptions, no FPN's, no directions to a different art #. :?:
- Location
- Windsor, CO NEC: 2017
- Occupation
- Hospital Master Electrician
Cavie, which aspect? It can be applied in whole as always.
What "maximum load to be served" is can be interpreted widely given the poor writing in 210.
Most AHJ's would likely conclude from the table in 220.55 that "max load to be served" is the demanded load mentioned in note 4 of 220.55.
Mark, somewhere about knee-deep in this mess I mentioned I believed the demand-load to be the 'max load', and Bob concurred shortly after. I lost track of who was voting for what after that point.
What "maximum load to be served" is can be interpreted widely given the poor writing in 210.
Most AHJ's would likely conclude from the table in 220.55 that "max load to be served" is the demanded load mentioned in note 4 of 220.55.
Mark, somewhere about knee-deep in this mess I mentioned I believed the demand-load to be the 'max load', and Bob concurred shortly after. I lost track of who was voting for what after that point.
Cavie
Senior Member
- Location
- SW Florida
I contend that the "Max load to be served" is the "Nameplate rating." Case in point. I inspected a job in which the "Manufacturers instalation instructions" calls for a 50 amp Circuit to be used. 12.5 kw 240 volt smooth top range. The electrician used the 220.55 (loophole as I call it) and ran a 8/3 rx on a 40 amp breaker. This is a 2 story house with the kitchen on an outside block wall. VERY difficult to run a new wire. What is he to do??? The problem I see here is after a few trips of the breaker at Xmas and Thanksgiving. (MY wife says this WILLlhappen), that sombody is going to install a 50 amp breaker on the 8/3 circuit and solve the problem. Now we have an overloaded wire. Now do that same thing with the 13.5 kw range that I have and you have overloaded the circuit by 16.25 amps. I guess the manufacturer is wasting money installing the
"Nameplate rating". It seams to serve no purpose. My CBO says "Let 'er go".
"Nameplate rating". It seams to serve no purpose. My CBO says "Let 'er go".
- Location
- Windsor, CO NEC: 2017
- Occupation
- Hospital Master Electrician
Then the violation is 110.3(B), not 210.19(A)(3).Cavie said:
If this is a common problem, and you sympathize with the installer's plight (that could be argued as self-inflicted) perhaps you should begin universally demanding appliance specifications at rough. The electrician should have them, because he should be demanding them from the GC as well. (All of this assuming a perfect world, of course.)
That's speculative, Cavie.
You should be inspecting the installation, not predicting the future, you know that speech.
Why do wives always come up in these types of discussions? Wives have such understated control over inspector's decisions sometimes. :lol:
For the purposes of 220.55, it serves as a starting point for calculations for service/feeder loads (for sure) and branch-circuit calculations (if we eventually contend that it can definutely be used on the branch circuit level, as it seems to state).
jeff43222
Senior Member
- Location
- Minneapolis, Minnesota
Sorry to butt in here ...
Even though the consensus seems to be that I can legally get away with installing a 40A receptacle in this case, I'm going to install 6/3 NM to a 50A receptacle and protect it all with a 50A breaker. Might as well allow for higher capacity.
You got a problem with that? You talkin' to me?
Even though the consensus seems to be that I can legally get away with installing a 40A receptacle in this case, I'm going to install 6/3 NM to a 50A receptacle and protect it all with a 50A breaker. Might as well allow for higher capacity.
You got a problem with that? You talkin' to me?
allenwayne
Senior Member
10 pages over something that has been done for years and years.......
The recep is a 50 you feel that 40 ocpd is pushing it use 6/3 and a 50 ocpd and be done with it.You guys have ALL to much time on your hands My brother just hooked up the boat and the grouper hole is calling me later dudes :idea:
The recep is a 50 you feel that 40 ocpd is pushing it use 6/3 and a 50 ocpd and be done with it.You guys have ALL to much time on your hands
My brother just hooked up the boat and the grouper hole is calling me later dudes :idea:
jwelectric
Senior Member
- Location
- North Carolina
Well it didn?t make it to 300 post but I didn?t like much making it to half that.
winnie
Senior Member
- Location
- Springfield, MA, USA
- Occupation
- Electric motor research
Okay, I know that this is a bad idea, but I was searching out this particular topic, and found this thread, and I just can't resist throwing in my $0.02
I've read through the entire thread, and I can see where Mike is coming from. I disagree with his interpretation, but I can see his point.
The sentence in question is 'For ranges of 8? kW or more rating, the minimum branch-circuit rating shall be 40 amperes.' This can be read in two different ways:
1) "A 40A circuit is the minimum requirement placed on this installation" The word _minimum_ gives permission to use a circuit this small in all cases. This reading makes this sentence 'trump' all other related code sections; no matter what the rest of the code says the circuit rating should be, you are only required to use the minimum and the minimum is 40.
If you use this reading of the sentence, then you can also restate this using the word maximum, as iwire did. If you read the word minimum as 'this is the minimum that you can use in all cases', then 40 amps is the _maximum_ that code requires of you for ranges. Under this reading, this sentence acts to reduce safety by permitting smaller circuits that will be overloaded.
2) "This installation must be sized by calculation. In all cases the size of this installation must be at least 40A" The second reading is that the word _minimum_ places an _additional_ requirement on top of all the other code requirements for range circuits. In this reading, you first do all the required calculations for range circuits. If the result comes out less than 40A, then you are required to use the minimum size 40A circuit. But if the result is something greater than 40A, then other sections of the code require you to exceed this minimum value. Under this reading, this sentence acts to increase safety by setting a minimum size for range circuits, no matter how small the actual calculated load.
If you go through the appropriate calculations called for, and find that by other code rules you could use a 30A circuit, this sentence says 'sorry, you must increase the circuit to a 40A circuit'.
I believe that the second interpretation is correct. 'Minimum' is not permission to use circuits smaller than the calculated range load on large ranges; instead it is a requirement to use circuits larger than the calculated range load on small ranges.
There are several examples of minimums in the code, where if you go through the various calculations and get a value less than X, then the minimum kicks in and you have to use X. If the calculations give a result greater than X, then you use the result of the calculations. Service sizes for residences, minimum ratings for lighting and receptacle circuits, wire gauge for different voltages, etc.
-Jon
I've read through the entire thread, and I can see where Mike is coming from. I disagree with his interpretation, but I can see his point.
The sentence in question is 'For ranges of 8? kW or more rating, the minimum branch-circuit rating shall be 40 amperes.' This can be read in two different ways:
1) "A 40A circuit is the minimum requirement placed on this installation" The word _minimum_ gives permission to use a circuit this small in all cases. This reading makes this sentence 'trump' all other related code sections; no matter what the rest of the code says the circuit rating should be, you are only required to use the minimum and the minimum is 40.
If you use this reading of the sentence, then you can also restate this using the word maximum, as iwire did. If you read the word minimum as 'this is the minimum that you can use in all cases', then 40 amps is the _maximum_ that code requires of you for ranges. Under this reading, this sentence acts to reduce safety by permitting smaller circuits that will be overloaded.
2) "This installation must be sized by calculation. In all cases the size of this installation must be at least 40A" The second reading is that the word _minimum_ places an _additional_ requirement on top of all the other code requirements for range circuits. In this reading, you first do all the required calculations for range circuits. If the result comes out less than 40A, then you are required to use the minimum size 40A circuit. But if the result is something greater than 40A, then other sections of the code require you to exceed this minimum value. Under this reading, this sentence acts to increase safety by setting a minimum size for range circuits, no matter how small the actual calculated load.
If you go through the appropriate calculations called for, and find that by other code rules you could use a 30A circuit, this sentence says 'sorry, you must increase the circuit to a 40A circuit'.
I believe that the second interpretation is correct. 'Minimum' is not permission to use circuits smaller than the calculated range load on large ranges; instead it is a requirement to use circuits larger than the calculated range load on small ranges.
There are several examples of minimums in the code, where if you go through the various calculations and get a value less than X, then the minimum kicks in and you have to use X. If the calculations give a result greater than X, then you use the result of the calculations. Service sizes for residences, minimum ratings for lighting and receptacle circuits, wire gauge for different voltages, etc.
-Jon
- Location
- Massachusetts
winnie said:
Had some time to kill huh?
:lol:
- Status