AWG size for Fluorescent Lighting

[Luzhin]

 I'm in the process of wiring some fluorescents and would like advice on wire size. 

I am wiring 8 two-tube T8 fixtures (total amperage = 4.5) on a 20-amp circuit.  I will run 12 awg wire to the first fixture, but after that (meaning from fixture to fixture) do I need to continue to use 12 awg?  The leads coming off the electronic ballasts are only 18awg.  The fixtures themselves will be butted end to end, minimizing travel.  Is it all right, once "inside" the fixtures, to only use 18awg?  (The total travel from the first fixture to the eighth will be about 32 feet.)

Thanks in advance,

Luzhin

[nbrodar]

 All wiring on a 20 amp circuit must be 12 AWG.

Nick

[cacole]

 You must comply with the National Electrical Code and any local supplemental electrical requirements for all house wiring, regardless of the purpose.

Most municipalities (at least here) publish a home owner's construction code pamphlet.  Check with your local City or County Building Inspection department where you live.  You may even need a permit.

If you do your own wiring without a permit and use the wrong type of wire which subsequently results in a fire, that could invalidate your homeowner's insurance.

Asking for professional electrical wiring advice on a forum of this type is almost as dangerous as asking for advice on performing your own brain surgery, because you don't say where you live and we don't know your local building code.

[60YOKID]

The 2008 National Electrical Code Art 402.6 "Minimum Size. Fixtures wire shall not be smaller than 18 AWG."

Once inside the fixture you can use #18 for not over 6 amps. It must be a type listed as fixture wire.  Most Electricians would just use #14 and be done with it.

Bill

Master Electrician & Inspector

[Allegheny2-6-6-6]

Check your local code but here code specifies #14 for lighting and interior receptacles.I wired my entire shop with #14 and used #12 for the 220 line for the compressor and the electrical inspector went away smiling so I guess I did it right.

[mfm37]

 What size is the breaker for that lighting circuit?

20 amp will require 12 gauge wire, 15 amp will need 14 gauge. Don't run larger wire into the panel if it's 15 amp. The inspectors in my area would fail it.

Best to call a licensed electrician to hook op those lights because quite frankly, your original question leads me to believe that 110 wiring is not your forte'.

 

[jeffrey-wimberly]

 If the house wiring that you connected the first fixture to a 12 AWG then that's what you continue with,

[IRONROOSTER]

Since you are asking, I recommend you get a professional.  Doing it wrong can have serious consequences.  The risk isn't worth the money you save

Enjoy

Paul 

[HaroldA]

I had thoughts of installing additional outlets and lighting myself but I did the smart thing and called an electrician.  What took him a couple hours would have taken me a couple days and it's neat, bu tmost importantly, it's up to code.  It's one thing to wire a layout, it's a totally different thing to wire 110.  Suggest you call a professional.

[ATLANTIC CENTRAL]

Allegheny2-6-6-6

Check your local code but here code specifies #14 for lighting and interior receptacles.I wired my entire shop with #14 and used #12 for the 220 line for the compressor and the electrical inspector went away smiling so I guess I did it right.

Obviously I can't speak about your local code for sure (since local jurisdictions can ad or change code requirements), BUT, the NEC does not PREVENT one from using 20 amp/#12 wiring for lighting and receptacle circuits. It simply allows 15 amp/#14 to be used for that purpose.

Most residential wiring is done with mostly #14 for economy and speed/ease of installation, but larger, higher end homes often take advantage of the reduced number of circuits required by using 20 amp circuits. My completely restored 1901 Queen Anne home has all the lighting and receptacle circuits wired with ALL 20 amp circuits/#12 wire, installed by me during the complete restoration of the home and the Inspector said it was one of the best jobs he had ever seem - quite the oposite from "specifies #14 for lighting and receptacles". 

To the OP, as the other qualified electrican on here said, a 15 amp circuit with #14 wire would be fine, but if you want you can use the #12 with a 20 amp or 15 amp breaker.

To the other poster who commented about too large a wire size and failing an inspection - not completely true, you have over simplified the facts. Virtually all 15 amp breakers are rated for up to #12 or #10 wire, which in commercial applications may be needed for long runs because of voltage drop. SO, if I bring a #12 wire into a pannel, and connect it to a 15 amp breaker who's connections are rated for #12 wire (or larger in some cases), it would be completely code legal and pass inspection.

Every time one of these questions come up on here, there is lots of miss-information, but, as many do suggest, if you don't know, get an skilled professional.

Sheldon

Electrical Designer, Electrician, Residential Architectural Designer, Old House Restoration Consultant, HVAC Designer, Old House Master Carpenter, Plumber 

[Lee 1234]

If you hardwire the 110 to the layout then the entire layout is subject to the local building codes and your home insurance. Run all layout wiring to a receptacle in the 20 amp circuit. From the receptacle plug you only need to run the wire size required for the lighting. Add a switch after the plug so you are constructing what amounts to a giant lamp. Enclose all connections in fixtures or boxes. I'd use 12 gage solid house wiring with the ground connected.