[NA] Sparky Q [NA]

Let'sgoflying!

Let'sgoflying!

Touchdown! Greaser!
Joined
Feb 23, 2005
Messages
20,315
Location
west Texas
Display Name
Display name:
Dave Taylor
I have a ~dozen new shop LEDs to install; T8 x 8' and as is typical the (Chinese) manufacturer does not reveal the amp draw; best as I can tell they are going to be around a half amp each. 1A max.
My question is about the cable choice; it seems like way overkill to run 12awg to each lamp from the existing incandescent fixtures. (6' run for each. One lamp on each connection; no daisy chaining)
However if I use anything smaller, the cable will not have the protection which the CB is designed for.
(I'm interested in what code says although such things are not subject to code inspection where I live.) [I accept the legal ramifications of my choices, so let's press on to the practicalities]
 
Use 16AWG and change breaker to 15amps?
 
i think a 8 or 10 amp breaker is code for 16 awg
 
Real question is what is the real savings in wire cost? Is it worth it to even bother? What if you need to add to it in the future?
 
Are these lights the only devices on this circuit?
 
For AC mains, under code, you fuse or CB for the wire size. You shouldn't use smaller wire without reducing the breaker as well.

The code requires that the breaker will positively trip before the wire could overheat and start a fire
 
Always thought it interesting that the in-wall wire up to each receptacle is protected by CB, but a homeowner can plug any device into it, of any size wire; and that wire is unprotected - an impracticality, I presume.
 
Let'sgoflying! said:
Always thought it interesting that the in-wall wire up to each receptacle is protected by CB, but a homeowner can plug any device into it, of any size wire; and that wire is unprotected - an impracticality, I presume.
Click to expand...

I agree. But then again, how many times have you read or heard of someone burning their house down with an inadequate extension cord? Think about it. The cord got hot enough to set the carpet on fire and the breaker on the outlet never noticed. It's expected (hoped) (wished) that the consumer will use common sense. :D

That said, UL (and equivalent) listings do require certain minimum sizes on cords. Don't quote me on this, but I suspect that's why you still see at least 18 gauge on LED lights. That will (hopefully) trip a 15A max breaker before it gets too hot. Length plays a part, too. It can get complicated.

We recently installed a new LED system on our 1,300' tower near Cullman, AL. The guy who installed it complained that we had a 30 A, 3-phase breaker (for the old strobes, which ATE power). I told him that the LED controller was supposed to have its own protection.

But like I said, it can get complicated. Just re-use the existing wire. Buy some of those nice firm-grip wire nuts or crimp fasteners that will work to connect the LEDs to what's already there.
 
You might think, the EE’s don’t give a flip about the consumer, about what happens past the outlet - but:
It would be impossible for a household electrical system to accommodate protection for every connected device & its wiring.
They could have a 1500W hair dryer (12.5A) or an iphone charger (a few amps). I think a dead short on the charger or something like that could generate enough heat to start fire.
 
Stephen Poole said:
I agree. But then again, how many times have you read or heard of someone burning their house down with an inadequate extension cord? Think about it. The cord got hot enough to set the carpet on fire and the breaker on the outlet never noticed. It's expected (hoped) (wished) that the consumer will use common sense. :D
Click to expand...
Happens more often than you think. especially in winter with space heaters.
 
Duh. I reread your initial. Just put outlets in the existing fixtures and put plugged cords to the LEDs. It'll look like you meant to.
 
hotprops said:
i think a 8 or 10 amp breaker is code for 16 awg
Click to expand...

Fixture wiring in the NEC says 16g is good for 8 amps. It doesn't however mandate a circuit breaker that small. 50 feet of 16 gauge is acceptable on a 15 or 20A branch circuit.
 
You must log in or register to reply here.
Back
Top