Replies

1. 
   Gunner | Sep 24, 2003 02:58am | #1

   Somebodies probably misquoting someone here. 20 amp for residential lighting in most cases is overkill. The main thing is no you don't want to tap into appliance circuits for under cabinet lighting. I don't have my code book here but it's like any other book of it's nature you can read a lot into nothing.

   Who Dares Wins.

2. 
   pm22 | Sep 24, 2003 03:24am | #2

    I noticed the same thing myself.

   Article or section 411-6 states "lighting systems operating at 30 volts or less shall be supplied from a maximum 20-ampere circuit.

   As for the more general rule, I found it once but can't find it again. But you can run household lights on either 15 amps or 20 amp circuits. What the author was probably refering to is you can't run the kitchen [or other] lighting from the two dedicated kitchen appliance circuits.

   ~Peter

   EDIT: Found it in Article 210-23 (a): "A 15- or 20- ampere branch circuit shall be permited to supply lighting units..."

   
   

   ---

   Edited 9/23/2003 11:47:25 PM ET by PM22

1. 
   Jamie_Buxton | Sep 24, 2003 06:48am | #4

   "Article or section 411-6 states 'lighting systems operating at 30 volts or less shall be supplied from a maximum 20-ampere circuit.'"

   Is that 20 amps at 120 volts (upstream of the transformer) or is it at the lamp voltage (downstream of the transformer)?

1. 
   BarryO | Sep 25, 2003 02:23am | #5

   My copy of 411-6 reads (1999 NEC):

   411-6. Branch Circuit. Lighting systems operating at 30 volts or less shall be supplied from a maximum 20-ampere branch circuit.

   So the 20A is the 120V branch.

   There were a number of "issues" with that article.  210-23(a) says 20A branches can be used for lighting, so I don't know where he got the prohibition from.

   ALso, he uses landscape wiring inside the walls.  Any low-voltage wiring inside walls needs to be CL2 or CL3 rated.

   They should have had an electrician review this article before publication.

   Edited 9/24/2003 7:24:13 PM ET by BarryO

1. 
   BillHartmann | Sep 25, 2003 04:08am | #6

   "There were a number of "issues" with that article. 210-23(a) says 20A branches can be used for lighting, so I don't know where he got the prohibition from."

   But read the Exception to that section.

   But the article was poorly worded. It should say that it can't be connected to on the 20 amp small applaince circuits.

1. 
   Wayfarer | Sep 25, 2003 08:18am | #7

   It seems like there are a couple issues perhaps:

   1) the maximum 20A issue for lighting; yeah, you can use the latter, but it is way overkill.

   2) tapping into a dedicated 20A circuit (for the kitchen) and its surrounds (ie as per code--dining room and whatever); no! this does not include lighting.

   Basically, as I see it, and I'm just now hooking up the lights in a house that I am wiring:  you have to have two 20A dedicated circuits in the kitchen and immediate area(s) for receptacles/outlets.  Lighting is a whole different deal; yeah, you can incorporate more 20A circuits, but why would you?  Unless of course some lighting is that draining (could it ever be?); at the most, you might find a dedicated fan or some other utility for a 15A circuit, but a 20A?   Nah, leave that for the microwave, dishwasher/disposal, etc.  Everything else in the kitchen is pretty straightforward spec-wise regarding oven, and some of the latter alluded to.

   Oh, and I forgot; I haven't read the new FHB Magazine--I'm a little behind in these parts of the Bay Area, CA.

   Edited 9/25/2003 1:19:59 AM ET by Wiley

2. 
   BarryO | Sep 25, 2003 10:01am | #8

   Yea, the exception would be the reason not to tap into the 2 dedicated circuits with a lighting load, but there is no general prohibition against attaching lighting to a 20A branch, which is what the article implied.

   Still concerned about the landscape wiring.  There's no assurance that wiring intended for low-voltage direct burial will meet the flame resistance required for in-wall installation.

3. 
   MisterT | Sep 25, 2003 01:24pm | #9

   My Two Cents,

   I don't know what the code says but...

   I think the gist of the authors comment was that you CANNOT connect a 14ga. circuit (most comonly used for lighting) to a 20amp circuit(12ga.).

   Mr T

   Do not try this at home!

   I am an Experienced Professional!

4. 
   BillHartmann | Sep 25, 2003 06:59pm | #10

   I had a change to read the whole article and feel that it was poorly written, in other areas than this.

   It did not seem to have a focus. More like a Family Handyman Magazine article rather than a "trade" magazine article.

   Now one thing that was not mentioned was fishing the NM. #14 is easier to handle then #12 so he might have gotten in the habit of using that for retro work, BUT that is not what he said.

   And someone else on the forum has said their inspector (I think in the Chiago area) won't allow lighting on 20 amp circuits. I don't know if that is a local rule or just some inspectors odd ideas.

5. 
   DanMorrison | Sep 27, 2003 03:45pm | #11

   Whoa buddy!

   It did not seem to have a focus. More like a Family Handyman Magazine article...

   That's hitting below the belt a little isn't it? I can handle screwing up an arbitrary and hard to read code, but lacks focus? poorly written? Oh man.

   I'm sorry, but you're gonna have to back that up a little bit.

   First we tell you why we're using the system we're using. Then we give an overview of the wiring scheme and talk about dimmers a little bit. There's a drawing illustrating the plan and explaining a little bit about low voltage wiring (bulbs, voltage drop). Then we give a one-page lesson on snaking wire through walls. The installation is very straightforward, as is hooking up the lights. But we go ahead and give a couple of tips on placement (towards the front, run it deep into the corners). Finally, we give the authors favorite system and why. Oh yeah, and as long as we have a photo of wire nuts, we tell the readers a little bit about them.

   Dan MorrisonOne happy assistant editor

6. 
   BillHartmann | Sep 27, 2003 03:54pm | #12

   I think that you made my point.

   "Finally, we give the authors favorite system and why. Oh yeah, and as long as we have a photo of wire nuts, we tell the readers a little bit about them."

   Anybody that is doing this should know enough to use a wire nut and that is part is not needed.

   If there is a new to have a review of different connection systems then that would be worthy of a whole 2 or 3 page article.

   I don't have the article in front of me, but I will try to go over it later.

7. 
   BillHartmann | Sep 27, 2003 09:46pm | #13

   "First we tell you why we're using the system we're using. Then we give an overview of the wiring scheme and talk about dimmers a little bit. There's a drawing illustrating the plan and explaining a little bit about low voltage wiring (bulbs, voltage drop). Then we give a one-page lesson on snaking wire through walls. The installation is very straightforward, as is hooking up the lights. But we go ahead and give a couple of tips on placement (towards the front, run it deep into the corners). Finally, we give the authors favorite system and why. Oh yeah, and as long as we have a photo of wire nuts, we tell the readers a little bit about them."

   Yes, a little bit about this and a little bit about that. What is the focus of the article, select the lights, installing them, proper wiring technics?

   If was about selecting them then it misses a lot of options. There article could just as well said that for this installation I am using XYZ and left more space for other details. Or discussed the different fixture options and left out the wire nuts, for example.

   I was going to complain about the use of "low voltage magnetic dimmers". They are never low voltage or magnetic, but I look a Lutron's catalogs and that seems to be the industry "mis"-terminology.

   But I did find something interesting. A number of the dimmers designed for controlling low voltage circuits do require a neutral. A standard switch leg does not have a neutral. That they would require pulling a 3 wire cable. Now that is the little kind of "gotcha" that would be usefull information in the article.

   You have a "Safety Tip" that say to make sure that the power is off to the box where you are adding the wiring. But at the sametime you are showing running a new circuit to the breaker pannel.

   In my mind those two just don't go together. If they have to bewarned about making sure that the power if off at the box they are should not be adding a circuit to the pannel.

   The paragraph on where to place the transformer and suggested hidding places was good. But then he goes on and discusses the difference between 12v and 24v systems. And talks about "centering" transformer to keep the LV wiring short. Some rules of thumb or design guide lines would have been more usefull here.

   Things don't alwasy work out so nicely where you can put transformer in the center.

   Also he "reused" a box slot where there was a switch for a dishwasher. Now that is an unusally setup. In most cases he would have added a new switch. And that usually entail added or changing a box. Since that is much more likely that should have been discussed.

   The drawing on page 63 indicates taht the transformer is mounted on pressure-treated plywood. I realy don't see that is in the scope of this article. And reason why requires information that is mentioned in the article.

   Aslo the drawing and the discussion indicates that power was run to the transformer and then a switch leg to the dimmer.

   However the picture on page 66 don't show that. (And I maybe wrong, but it does not appear to mounted on PT plywood).

3. 
   HeavyDuty | Sep 24, 2003 04:00am | #3

   The two sentences

   "...the NEC requires lighting to be on a 15-amp circuit.  [therefore] I couldn't tap into the 20-amp appliance circuits."

   are confusing, they do not relate. PM's explanation was probably the original intention of the auhtor. May be you should ask the auther himself.

   Tom