# Tap rules



## RePhase277 (Feb 5, 2008)

martinkulik said:


> Does anyone can explain to me about the tap rules in overcurrent protection.
> I am not sure where to use it nor how to do it.
> Thanx Martin:001_huh:


There are several tap rules. Which one(s) are you referring to?


----------



## martinkulik (Jan 9, 2009)

*Respond*

Hi,
I was talking about the article 240.21. Where would you use usually use it. I just do not exactly understand it.
Thank you.
Martin


----------



## RePhase277 (Feb 5, 2008)

If you think about it, the secondary of any power transformer is an application of the tap rules. The tap rules more or less say that you can connect a smaller wire to a feeder than would normally be allowed by that wire's ampacity. For example, the secondary of a transformer may be capable of delivering 300 amps, unfused, but we can feed a 200 A panel with 3/0 copper from it, if we meet a few requirements.

We also see it in industrial setups feeding several motors. We might have a 400 A circuit in a trough, feeding three 100 A disconnects with #3 copper. We can do this if 

1) The tap conductors are not less than the rating of the device supplied
2) The conductors don't leave the device they terminate in
3) The conductors are enclosed in a raceway
4) The rating of the overcurrent device that feeds the circuit isn't more than 10 times the ampacity of the tap conductors

I'm not very good at examples, but I hope this helps.


----------



## manchestersparky (Mar 25, 2007)

A lot of residential electricians use the tap rule when they have a cook top and a seperate built in oven. One feed from the panel to a J-box then 2 feeds tapped to that one. One to the cooktop and the other to the built in oven


----------



## JohnJ0906 (Jan 22, 2007)

manchestersparky said:


> A lot of residential electricians use the tap rule when they have a cook top and a seperate built in oven. One feed from the panel to a J-box then 2 feeds tapped to that one. One to the cooktop and the other to the built in oven


Strangely enough, I have never seen an install like this.

In almost every instance, where I have been the installer, the cooktop and wall oven(s) are separated by too much distance to make this practical.

Now, is this rule different from the Article 240 tap rules, in that the taps do not need to be terminated at an OCPD?


----------



## JohnJ0906 (Jan 22, 2007)

manchestersparky said:


> A lot of residential electricians use the tap rule when they have a cook top and a seperate built in oven. One feed from the panel to a J-box then 2 feeds tapped to that one. One to the cooktop and the other to the built in oven


This is 210.19(A)(3), exception #1, for those of you following at home....


----------



## jbfan (Jan 22, 2007)

JohnJ0906 said:


> Strangely enough, I have never seen an install like this.
> 
> In almost every instance, where I have been the installer, the cooktop and wall oven(s) are separated by too much distance to make this practical.
> 
> Now, is this rule different from the Article 240 tap rules, in that the taps do not need to be terminated at an OCPD?


I agree. Most cases the cooktop is on one side of the kitchen and the oven was on the other side.

I just wire the separately anyway.


----------



## acrwc10 (Jan 28, 2007)

JohnJ0906 said:


> Strangely enough, I have never seen an install like this.
> 
> In almost every instance, where I have been the installer, the cooktop and wall oven(s) are separated by too much distance to make this practical.
> 
> Now, is this rule different from the Article 240 tap rules, in that the taps do not need to be terminated at an OCPD?


I only see this in houses built in the 50's and 60's around here. Now you would be hard pressed to do this legally because in the installation instructions that come with them it will most likely call for a "dedicated circuit" 110.3(B) "listing and labeling" just when it all starts to look easier, BAM, they hit you with 110.3(B)


----------



## RePhase277 (Feb 5, 2008)

acrwc10 said:


> I only see this in houses built in the 50's and 60's around here. Now you would be hard pressed to do this legally because in the installation instructions that come with them it will most likely call for a "dedicated circuit" 110.3(B) "listing and labeling" just when it all starts to look easier, BAM, they hit you with 110.3(B)


I agree there. But as far as this thread goes, the OP wasn't talking about the tap rules of 210.19. But the taps rules of 240.21, feeder taps, 10' rule, etc.


----------



## manchestersparky (Mar 25, 2007)

JohnJ0906 said:


> Now, is this rule different from the Article 240 tap rules, in that the taps do not need to be terminated at an OCPD?


Sorry about the delay .
Yes it is different - read 210.19(A)(3) Exception No. 1 -
it covers factory installed AND field installed tap conductors.
The exception permits a 20 amp tap from a range, oven, or cooking unit to be connected to a 50 amp branch circuit if the following are met:

1-taps are not longer then necessary to service or permit access to the junction box

2- Taps to each unit are properly spliced

3- Junction box is adjacent to each unit

4- Taps are of sufficient size for the load to be served.

Look in the NEC Handbook for exhibit 210.22


----------



## Pierre Belarge (Feb 3, 2007)

manchestersparky said:


> Sorry about the delay .
> Yes it is different - read 210.19(A)(3) Exception No. 1 -
> it covers factory installed AND field installed tap conductors.
> The exception permits a 20 amp tap from a range, oven, or cooking unit to be connected to a 50 amp branch circuit if the following are met:
> ...


 
I looked at the commentary. Where in the NEC does it actually require #3, Junction box is adjacent toe each unit????

In reading #1, it does not state this. I also can see that the tap conductors can be longer than just adjacent to the Jbox in this wording.


----------



## slowforthecones (Sep 13, 2008)

martinkulik said:


> Does anyone can explain to me about the tap rules in overcurrent protection.
> I am not sure where to use it nor how to do it.
> Thanx Martin:001_huh:


Hack....... go back to the home depot parking lot.


----------



## Larry Fine (Oct 24, 2007)

slowforthecones said:


> Hack....... go back to the home depot parking lot.


That was uncalled for. Not everyone is a seasoned Master with years of NEC training.


----------



## slowforthecones (Sep 13, 2008)

If you do a search or read what "martinkulik" has posted on the forum..you will know why I am calling him a hack. This guy is no electrician or apprentice.


----------



## brian john (Mar 11, 2007)

slowforthecones said:


> Hack....... go back to the home depot parking lot.


I guarantee there are JWs on this forum that can make you look like you were a green apprentice. 

Believe it or not this forum is actual for asking such questions and it is better he asked then go around unsure of how to to something.


----------



## Toronto Sparky (Apr 12, 2009)

manchestersparky said:


> A lot of residential electricians use the tap rule when they have a cook top and a seperate built in oven. One feed from the panel to a J-box then 2 feeds tapped to that one. One to the cooktop and the other to the built in oven


I would think a four circuit panel would be in order.. Thats what I would do anyway.


----------



## micromind (Aug 11, 2007)

I have to agree with Brain and Larry; there are no dumb questions, but there are tons of dumb guesses.

Rob


----------



## mikeg_05 (Jan 1, 2009)

slowforthecones said:


> If you do a search or read what "martinkulik" has posted on the forum..you will know why I am calling him a hack. This guy is no electrician or apprentice.


Did this guy work for you at one time? You sure have some harsh words about him. I read his posts, they all seem legit. Like Brian said, rather have him ask the question then not. Keep those comments to yourself.


----------



## lbwireman (Jan 22, 2007)

mikeg_05 said:


> Did this guy work for you at one time? You sure have some harsh words about him. I read his posts, they all seem legit. Like Brian said, rather have him ask the question then not. Keep those comments to yourself.


I agree. If you can't manage to "behave like a gentleman" as my Gramma used to admonish me, at least try to muster a little civility.


----------



## slowforthecones (Sep 13, 2008)

you guys are right, I had harsh words for this guy. Opps..


----------

