Hardwiring lights to a 20 amp circuit


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Old 06-29-14, 04:28 PM
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Hardwiring lights to a 20 amp circuit

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I have a 20 amp circuit running in my barn. I wish to hook 3 or 4 fluorescent lights to the circuit if i can. Each of the lights has a much smaller wire to connect to. Can i put in a junction box and use a wire nut to connect the lights to the 12 guage wire and still use a 20 amp circuit breaker? If I can do this is there a limit to the length of wire? For example I want to go from a junction box to 2 different lights each about 5 feet from the box.
 
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Old 06-29-14, 05:42 PM
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Each of the lights has a much smaller wire to connect to. Can i put in a junction box and use a wire nut to connect the lights to the 12 guage wire and still use a 20 amp circuit breaker?
If these are cheap shop lights with a cord and plug that you want to hardwire, it would void the U.L. Listing to cut the plug off and hardwire the cord. I'd suggest removing the cords entirely and wiring the fixtures internally from the junction box with an appropriate 12-2 cable.
 
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Old 06-29-14, 06:36 PM
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If they do have cords, why not just install receptacles that are switched. Then just plug them in.

If they do not have cords, then wire them directly as Joe suggests and skip the J-boxes all together. However if you do want to install junction boxes, there is no limit of how long the cable from the box to the fixture has to be. Proper support just needs to be followed.
 
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Old 06-29-14, 06:37 PM
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If you are asking if the smaller fixture wire can be used on a 20 amp circuit the answer is yes.
 
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Old 06-29-14, 10:23 PM
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The wiring coming off the ballast is usually 14 gauge, and often not high quality. Even so, this is fine for the fixture. Most 4' lamps tend to draw about 0.7a each, though you can find the specifications on the ballast itself. Wire nut them in as you would any lamp. The total amp draw will be insignificant. Just be sure to use the proper wattage bulbs and install a decent switch.

As far as that goes, I recently purchased an inexpensive Lithonia 2x40w lamp that gave me trouble at the switch, on a new install (similar to yours). The switch arc'd & I drove myself crazy as to why. I swapped out the cheap switch to a 15/20a switch, and I replaced the fixture with a different lamp. Problem gone. The only difference between those 2 fixtures is that the new one [Utilitech] explicitly states "electronic ballast", while the first one [Lithonia] said nothing about it.

Not sure if that matters, but I know what ultimately worked for me.
 
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Old 06-30-14, 03:56 AM
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iamrennie wrote:

The wiring coming off the ballast is usually 14 gauge, and often not high quality. Even so, this is fine for the fixture.
Just curious, what kind of ballast are you using that have 14awg leads? Why do you think ballast leads are not "high quality"?

The total amp draw will be insignificant.
Adding 4 fluorescent fixtures to a circuit must be calculated like any other load to assure overloading is not occurring. So you cannot comment on the significance of the amp draw without looking at the bigger picture.
 
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Old 06-30-14, 09:03 AM
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Most fixtures are coming with electronic ballast due to energy saving requirements. Magnetic ballast are on thew way out.
 
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Old 06-30-14, 10:55 AM
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Magnetic ballasts for the common T12 lamp aren't even manufactured any more. There is an electronic replacement ballast for the old T12 magnetic ballasts.
 
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Old 06-30-14, 10:57 AM
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Just curious, what kind of ballast are you using that have 14awg leads? Why do you think ballast leads are not "high quality"?
All the 4' & 8' ballasts installed in my home/shop have been 14 or smaller gauge (11 in all). I'm sure they are varied by manufacturer, but the questioner was comparing it to 12. I guess I could have just said "smaller"? The leads on most inexpensive ballasts aren't exactly high quality, as compared to new romex/dx/etc. Since it's in his barn, I'm guess he's not going high-end fixture here. The statement was only in reference to them functioning properly for the job, though perhaps unnecessary. -1 for me being flowery, I suppose.

Adding 4 fluorescent fixtures to a circuit must be calculated like any other load to assure overloading is not occurring. So you cannot comment on the significance of the amp draw without looking at the bigger picture.
As I stated, 4' lamps generally pull about 0.7a+ each. There is no bigger picture explained, so why would we guess at every possible variable? Even so, let's assume he's adding even 3-4a to the circuit here. If that overloads it, there was already a potential problem. I was assuming the poster is familiar with his amp draw, since that didn't seem to be the question. Perhaps "a minimal draw" would have been a more acceptable phrasing. Although I fully understand your points, your questions should probably be directed at the poster here.

oldman32: Be aware of your total amp draw. And as pcboss already stated, the smaller fixture wire can be used on the 20a circuit.
 
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Old 06-30-14, 11:02 AM
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oldman32: Be aware of your total amp draw. And as pcboss already stated, the smaller fixture wire can be used on the 20a circuit.
The smaller wires feeding the ballast inside the fixture are OK on a 20 amp circuit. Smaller wires between the junction box and the fixture are not acceptable.
 
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Old 07-04-14, 04:38 PM
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Thanks to all that replied to my post, I appreciate your help. The total amp draw on the circuit is small. The extra few amps due to the lights will not be a problem. The lamps do come with a 5 foot plug in cord. My initial thought was to cut the plug off near the end and just hard wire the end of the cord in a junction box (the power to that box would be switched). A better approach as was suggested would be to put receptacles in and just plug them in and I am now going to do it that way.
Thanks..
 
 

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