Question on a branch circuit

[lzicc]

I am going to be installing new LED shoplights in my garage. I am going to tap off a 20 amp plug circuit. Since these are for lights only, can I run 14/2 wire for the lights? Nothing else will be in the branch other than these LED shoplights.

 

[frugalangler]

Although nothing you install will be, a circuit protected by a 20A breaker should have 12Ga wire downstream in case someone else taps off the branch you install

 

[lzicc]

If the end of the branch circuit ends inside the last shop light, I wouldn't think anyone would think about tapping into it. Is it safe if that is the case? I can use 12/2 wire, but it is so much thicker than 14/2 for lights, especially for LED shoplights since they are so narrow to begin with. I am going to be installing 4 of them on the same circuit and want to put them on a wall switch.

 

[RNeumann]

Code requires 12awg wire if it is protected by a 20a breaker. If this is a code question, that's the answer.
If you are simply asking what will "work" I would only recommend following code as that is best accepted practice.

 

[CobyRupert]

Code requires 12awg wire if it is protected by a 20a breaker. If this is a code question, that's the answer.
If you are simply asking what will "work" I would only recommend following code as that is best accepted practice.

Correct: The code requires you protect #14awg wire with a 15 amp breaker
(read here)
even though it has a rated ampacity of either 20amps (w/ cable insulation
(read here)
and terminations having a 75 deg C rating), or
(read here)
25 amps (w/ 90 deg C rating).
(read here)
If you're adding (say) 360 Watts of LED lighting, the lights will draw 3 amps.
(read here)
People aren't going to explicitly advise you to ignore the code.

 

[CADplans]

You can change the breaker to 15 amps,, and use 14 gauge wire,,,

 

[RNeumann]

Correct: The code requires you protect #14awg wire which has a rated ampacity of 20amps (if cable insulation
(read here)
and terminations have a 75 deg C rating), or 25 amps (if 90 deg C rated) with a 15 amp breaker.
(read here)
If you're adding (say) 360 Watts of LED lighting, the lights will draw 3 amps.

Not sure what where this is going. OP is talking 12/2 vs 14/2- these are common terms for what the code calls NM- commonly called Romex.

If OP turns this into another type of wire I'd be happy to offer advice about that. Until then it's 12/2.

Btw- don't forget OCPD min wire size in 240.4D. It's more than just the chart.......14awg copper- no matter the type- is 15a OCPD, 12awg- 20a etc

 

[CobyRupert]

Yes. The code requires you to use a 15 amp breaker to protect a cable that is likely rated for 25amps and may have a load of (say) 3 amps on it.
I don't disagree.

Why, did you read something else between the lines?

 

[quicksandfarmer]

There is one loophole to the general rule that the wire has to be the same size throughout: the wire between an outlet and a device can be smaller.

Install an outlet box. Put a plug cord on the lights and plug it into the outlet.

 

[lzicc]

That is what I am thinking about doing.

There is one loophole to the general rule that the wire has to be the same size throughout: the wire between an outlet and a device can be smaller.

Install an outlet box. Put a plug cord on the lights and plug it into the outlet.

 

[CobyRupert]

There is one loophole to the general rule that the wire has to be the same size throughout: the wire between an outlet and a device can be smaller.

Install an outlet box. Put a plug cord on the lights and plug it into the outlet.

Yes, but now the receptacle has be GFCI (as per 210.8 (B) 8). The conductor to the receptacle (served from the 20 C/B) has to be #12Awg, and a single receptacle on a 20A branch service has to have a 20 amp (not 15A) rating too! (as per 210.21(B))

Just swap the 20A C/B for a 15A C/B.... or....

Will your LED lights drawing __amps ever overload /overheat the #14 Awg cable?
Will you be able to sleep at night if it's not to code? ....but somehow be able to sleep at night if it's to code but you use the loophole that still uses the same ___amps running down the same #14 cable?
This is where someone mentions liability and ...and the "What if's" & getting lawyers involved!

 

[quicksandfarmer]

Yes, but now the receptacle has be GFCI (as per 210.8 (B) 8). The conductor to the receptacle (served from the 20 C/B) has to be #12Awg, and a single receptacle on a 20A branch service has to have a 20 amp (not 15A) rating too! (as per 210.21(B))

Just swap the 20A C/B for a 15A C/B.... or....

Will your LED lights drawing __amps ever overload /overheat the #14 Awg cable?
Will you be able to sleep at night if it's not to code? ....but somehow be able to sleep at night if it's to code but you use the loophole that still uses the same ___amps running down the same #14 cable?
This is where someone mentions liability and ...and the "What if's" & getting lawyers involved!

I'm pretty sure just about all of the lamps in my house have 18 gauge lamp cord and they're UL listed. This is what I meant by the loophole -- the outlet can be 20 amps with 12 gauge wire, but it's perfectly legal to have 18 gauge between the outlet and the lamp.

Find a lamp that is UL listed and the manufacturer's instructions provide for a plug in power cord and for daisy chaining. This is really common with LED fixtures now. Something like this:
Commercial Electric 4 ft. White LED Linkable Shop Light-5413161 - The Home Depot

According to the description you can chain up to nine of them together. They can be chained end-to-end, they come with a 14-inch linking cable and longer cables are available. Put in a single switched outlet on your existing 20-amp circuit and call it a day.

 

[mbohuntr]

I'm pretty sure just about all of the lamps in my house have 18 gauge lamp cord and they're UL listed. This is what I meant by the loophole -- the outlet can be 20 amps with 12 gauge wire, but it's perfectly legal to have 18 gauge between the outlet and the lamp.

Find a lamp that is UL listed and the manufacturer's instructions provide for a plug in power cord and for daisy chaining. This is really common with LED fixtures now. Something like this:
Commercial Electric 4 ft. White LED Linkable Shop Light-541�3161 - The Home Depot

According to the description you can chain up to nine of them together. They can be chained end-to-end, they come with a 14-inch linking cable and longer cables are available. Put in a single switched outlet on your existing 20-amp circuit and call it a day.

I believe that's because the end load is fixed, (nothing more can be added) is approved by the UL.. a simple branch with an outlet can easily be overloaded and exceed the ampacity of the wire and smoke the wire before the oversized breaker trips. So It's not really a loophole... you can plug 2 microwaves into a 15 amp outlet, but the 14 guage feed is still protected by the 15 amp breaker, so no smoke...

 

[RNeumann]

I believe that's because the end load is fixed, (nothing more can be added) is approved by the UL.. a simple branch with an outlet can easily be overloaded and exceed the ampacity of the wire and smoke the wire before the oversized breaker trips. So It's not really a loophole... you can plug 2 microwaves into a 15 amp outlet, but the 14 guage feed is still protected by the 15 amp breaker, so no smoke...

Exactly correct. If you have a 15,20,40,100 or 200 amp circuit, all the wires must be sized accordingly.

But each appliance or device is wired or sized for that individual device. That is why you can plug your tiny cell phone cord into a 15 or 20a circuit.

 

[LD1]

If all that's going on is lighting, how freaking hard is it to change to a $5 15a breaker? Why is this question being ignored by the op?

 

[RNeumann]

Because of the OPs original post. He is continuing the existing plugs circuit in the shop. If OP changed a breaker he is losing amperage on the plug circuit.

We are on the same page on this though. How hard is it to run 12/2 vs 14/2 up to some new lights?

 

[LD1]

Are the rest of the plugs being heavily loaded?


I have had my shop built for 2 years now. The 40x40 section that has power has probably 20-25receps on 6 or 7 circuits. Some things never get unplugged, ever. Like wood burner blower, air conditioners in the windows, cord reel, shop light, etc. But that's only a few things. There are probably 1/2+ of the outlets I have never used.

So to me this is a no brainier and you really only have two choices (other than a new circuit).

1. 15a breaker and 14ga wire
2. 20a breaker and 12ga wire.

Yes, it really is that simple.

 

[quicksandfarmer]

Because of the OPs original post. He is continuing the existing plugs circuit in the shop. If OP changed a breaker he is losing amperage on the plug circuit.

We are on the same page on this though. How hard is it to run 12/2 vs 14/2 up to some new lights?

OP says it's a garage. He doesn't say it's detached but my bet is it is. There is a special provision for running a single 20-amp circuit to a detached building, if it is GFCI-protected it doesn't have to be trenched very deep and the wiring is much simpler. So adding another circuit is a big deal. Losing the full 20-amp capacity could also be a big deal.

 

[LD1]

OP says it's a garage. He doesn't say it's detached but my bet is it is. There is a special provision for running a single 20-amp circuit to a detached building, if it is GFCI-protected it doesn't have to be trenched very deep and the wiring is much simpler. So adding another circuit is a big deal. Losing the full 20-amp capacity could also be a big deal.

If so, it's just a few lights then. And cost difference is nil. Just run the 12 ga

 

[JPRambo]

Yes, but now the receptacle has be GFCI (as per 210.8 (B) 8).

The receptacle does not need to be GFCI if it is NOT 'readily accessible'. As in mounted 6 feet or more above grade. ( On the ceiling? ).