#14 switch legs on 20A OCP

[LarryFine]

The few I can think of are UC lighting like Little Inch LINK. Both of which are listed systems of components. Would you tap into those for other fixtures?

I don't believe the link wires would be considered premises wiring. They're lamp cord.

 

[e57]

I don't believe the link wires would be considered premises wiring. They're lamp cord.

Exactly....

 

[mivey]

So the NEC either allows these conductors, say, in a raceway (402.7) to extend from a "point on the wiring system at which current is taken to supply lighting equipment" (Art. 100 / Outlet) to a luminaire(s) some distance away, or they are talking about really big fixtures.:grin:

But the raceway can not be concealed either. Wires in a concealed raceway are considered to be concealed.

add: Well, I think that is for felxible wire. But I'll modify to say the wire in conduit can't be a replacement for branch wiring.

 

[iwire]

It doesn't, and in context - I did not say that was the case... You asked for a code ref' for a sentance out of context. (lookin' to pick a bone wit me... :roll

Anyway - 402.11 does not allow fixture wire as premise branch wiring... Where would you tap more on to it anyway????

For instance: Those plug in daisy chained drop-in fixtures - the plugs for them are #12 - and intended to carry a 20a circuit. But I can think of few fixures rated to feed thru to others that use conductors smaller than that. The few I can think of are UC lighting like Little Inch LINK. Both of which are listed systems of components. Would you tap into those for other fixtures?

For instance, I hang ten 8' strip fixtures coupled together, each one draws .75 amps. I would think I could use 16 AWG fixture wire supplied with a 20 amp branch circuit to join all these units.

 

[Volta]

But the raceway can not be concealed either. Wires in a concealed raceway are considered to be concealed.

add: Well, I think that is for felxible wire.

I think your'e right, the concealment issue is for flexible cords and cables (400), not fixture wire (402).

But I'll modify to say the wire in conduit can't be a replacement for branch wiring.

But it can.

Full Section text

Fixture wires shall not be used as branch-circuit conductors except as permitted elsewhere in this Code.

Then back to "elsewhere", a.k.a. 240.5(B)(2). :grin:

 

[mivey]

But it can.

Full Section text

Then back to "elsewhere", a.k.a. 240.5(B)(2). :grin:

That just feels so......trashy.:grin:

 

[GrayHeadedMule]

From NECplus.org

Question:

Can 14-2 wire be used for the switch leg of a light fixture where the branch circuit is protected by a 20-amp circuit breaker? If this is prohibited by the Code, why can 15-amp switches and receptacles be used on 20-ampere circuits?


Answer:
The conductors from a switch location to the lighting outlet it controls are considered branch-circuit conductors, not tap conductors connected to branch-circuit conductors. These conductors are subject to the general overcurrent protection requirements of 210.20(B), which points to 240.4 for the specific overcurrent protection requirement. Section 240.4(D) specifies that 14 AWG copper conductors are to be protected by an overcurrent protective device with a rating or setting no higher than 15 amperes. Table 210.24, which summarizes the requirements for branch circuits with two or more outlets or receptacles, specifies that the minimum conductor size for a 20-ampere-rated branch circuit is 12 AWG.
Section 210.21(B)(3) permits a 15-ampere receptacle to be connected to a 20-ampere rated branch circuit. The terminals of feed-through type receptacles rated 15 amperes are tested for the heating that will result from the full load of a 20-ampere branch circuit. In addition, the attachment caps of cord-and-plug-connected appliances are configured based on the appliance load. If the appliance is rated greater than 15 amperes, its cord cap will not be compatible with the configuration of a 15-ampere receptacle.
Snap switches installed on branch circuits are subject to the load requirements specified in 404.14. For ac general-use snap switches controlling resistive or inductive lighting loads, the minimum rating cannot be less than the load it supplies. In other words, a 15-ampere switch installed on a 20-ampere circuit can supply a load of 15 amperes. For switches controlling lighting outlets supplied by 15- and 20-ampere branch circuits, it is the load controlled by the switch and not the rating of the branch circuit that determines the switch's minimum ampere rating.

 

[Article 90.1]

I DID NOT vote that it was allowed, but there was a time a few years back when the regional supervisor for TN State inspectors confirmed a State policy (unwritten) that #14 could be used on a 20 amp circuit as a "switch leg" for a light fixture as long as no neutral was in the cable (thus only cables from the light down to a switch). The few inspectors that I know that accepted this, discontinued the practice on his retirement.

(the primary difference in our organization and the Boy Scouts is that the Boy Scouts have adult leadership)

I have always referred to what this particular inspector said was allowable as a "switch loop," a "switch(ed) leg," necessarily has a neutral, whereas a sw. loop does not.

 

[LarryFine]

"If the appliance is rated greater than 15 amperes, its cord cap will not be compatible with the configuration of a 15-ampere receptacle."

Well, we know that's not always true.

 

[srblx]

bottom line

bottom line

I feel no need to post the article no#s since everyone else has done so. To answer the original question #14 used as a switch leg on a 20A branch circuit? The bottom line and answer is NO

When I first started as an apprentice this was a common practice with the company I worked for and accepted by the AHJ until 3 years ago. Our AHJ changed hands and this is no longer an acceptable practice. I am proud to say I never used this method on any of my own projects and I left that place of employment as quickly as I could. I do not believe in taking chances with mine or anyone elses life and believe this is what makes me the electrician I am.

 

[Jim W in Tampa]

I can't believe something this simple is still going. If you follow NEC the answer is a flat NO. Now if your talking back woods country with blind or ignorant inspectors then i can believe you been getting away with it and just been flat out lucky.

 

[G0049]

Another thread, a week or so ago, referenced the local amendments in Spencer IA. It had a link to the city codes. Here's a quote:

"C. Branch Circuit Requirements:

1. In dwellings, all branch circuit wiring shall be no less than no. 12, 60 degree cent., AWG solid copper wires, with no more than eight (8) duplex receptacles per circuit in the living area.

2. In dwellings in the kitchen counter area, there shall be a minimum of three (3) circuits supplying one duplex receptacle each.

3. In dwellings, switch leg wiring shall be no less than no. 14, 60 degree cent., AWG solid copper wire...."

It looks like the city fathers are telling you in paragraphs 1 & 3, that the branch circuit has to be wired with no. 12, but the switch legs can be no. 14.

Go figure. Then read 2. Three SABCs each supplying ONE recep. each?

 

[LarryFine]

... all branch circuit wiring shall be no less than no. 12, ...

... switch leg wiring shall be no less than no. 14, ...

Apparently, switch legs aren't branch-circuit wiring. :roll:

It looks like the city fathers are telling you in paragraphs 1 & 3, that the branch circuit has to be wired with no. 12, but the switch legs can be no. 14.

Go figure. Then read 2. Three SABCs each supplying ONE recep. each?

It sounds like "good ol' boy" mentality.

 

[renosteinke]

The last time I discussed this, some troll got all upset, and thought I was being disrespectful of plumbers.

Why? Because I said we're not plumbers, we're electricians ... so we ought not think like plumbers.

How does a plumber think? If your office has a sprinkler system, look at it. A big pipe comes in, and afs it passes heads, the piping gets smaller and smaller. You go from 12" riser to 1/2" head, without a single 'over-current' device in the mix.

When someon downsizes their branch circuit wiring, even just the switch loops, they're thinking like a plumber. They're just thinking about the expected demand of the 'fixture,' and sizing the 'pipe' just big enough to assure it has enough flow to work.

Now, we look at things differently. WE have circuit breakers and fuses. So, we size the wire to be able to handle the maximum that breaker can deliver - not to just what we think we need. We follow this principle all the way up to the appliance or fixture. Once inside that fixture, then we let the engineers play around with a different set of rules.

Keep in mind that if a pipe breaks, there is no device that will say 'too much water is flowing, I better shut off the line.' Yet, that is exactly what we use circuit breakers for- to shut things off if there is clearly something wrong.

 

[480sparky]

.............Keep in mind that if a pipe breaks, there is no device that will say 'too much water is flowing, I better shut off the line.' ...............

Uh, hate to break it to you, but there is.

http://www.flologic.com/Automatic-Water-Shutoff-System.html

 

[iwire]

When someon downsizes their branch circuit wiring, even just the switch loops, they're thinking like a plumber. They're just thinking about the expected demand of the 'fixture,' and sizing the 'pipe' just big enough to assure it has enough flow to work.

OK, explain why I can use a 15 amp switch on a 30 amp circuit if the load is under 15 amps. :grin:

 

[jxofaltrds]

OK, explain why I can use a 15 amp switch on a 30 amp circuit if the load is under 15 amps. :grin:

You need two in series!

 

[jaylectricity]

OK, explain why I can use a 15 amp switch on a 30 amp circuit if the load is under 15 amps. :grin:

Same reason you can put a 15 amp duplex receptacle as the only device on a 20 amp circuit.

OK, not the same reason at all.

 

[PetrosA]

A little bit of understanding

A little bit of understanding

Actually, I CAN understand why some electricians might think this was ok to do but in my area they would have to be about 75 years old at least In houses around here built up to the 1950s or 1960s, lighting circuits were run from 4" round to 4" round, with switches dropped out of each 4" round box. It was pretty much a given that the load on the switch leg was never going to be larger than a two lamp fixture. A single 20A circuit would handle the lighting load of most of the house, and #14 for the switch legs (loops) would save money without creating a hazard (back then...). Nowadays in resi we wire the feed to the switch which makes it possible to fully load a lighting circuit on one switch so it would be very bad practice to feed a switch with #12 and then feed the lighting with #14. But if someone works in an area where running the feeds to the ceiling boxes is still done, they probably wouldn't see any danger in using a #14 switch leg.

 

[roger3829]

What's wrong with running the feed to the light?