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gcan 09-29-2012 03:12 PM

under cabinet lighting wire size
I have a switch that was wired for an outlet under the sink maybe for a disposal which I don't have instead I used the switch to power four 12" flouresant T-5 under cabinet lights. I direct wired the lights together one to the other then but I ran out of 12/2 wire and instead ran 9' of 14/2 wire to the last light, it was late Sunday night and I wanted to get done. From the switch to the first light is in the wall the rest of the wire is exposed, inside the cabinet's. This is all that I can find on the 20 amp circuit.
I've since read here that 20 amp breakers normally use 12/2 wire.

Do I need to go back and change the 14/2 to 12/2 for the last light?
I ask because:
  1. it's a pain in the but to fit all those wires in those small lights
  2. they came with lamp cord that could have been used to jump from one to the other
  3. they're on a switch that is off 90% of the time.
Thanks in advance

Jim Port 09-29-2012 03:20 PM

You cannot protect a #14 with a 20 amp breaker. You can either replace the #14 or change the breaker to 15 amps.

bobelectric 09-29-2012 03:24 PM

Read about tap rules. You are legal.

gcan 09-29-2012 03:54 PM

bob - I'll read the tap rules - thank you

Jim - protect it? surely the 14/2 can handle more than the lamp cord that comes with these lights

I do not know how to change a breaker, actually being a DIY'er I have always avoided working in the main panel

gcan 09-30-2012 07:13 AM

what gauge is standard lamp cord? With the code requiring certain gauge wire for safety are the cords also regulated?

My point being on my garage I used the lamp cord provided to plug in the undercabinet lights and then daisy chained two other lights again with the wire provided.

Should I change those lighs as well?

k_buz 09-30-2012 07:48 AM

If those lights came as a kit and the instructions say you are able to do it that way, they also probably give you a limit of how many lights you can wire together using the lamp cord. If you stay within those manufacturer specs, you are fine.

Jim Port 09-30-2012 07:52 AM

The load on the fixture wires is known. This is why they are allowed to be smaller. The load on building wiring is not known and needs to be sized properly in order to be protected by the breakers.

gcan 09-30-2012 08:09 AM

(just trying to understand) - how is it different using the supplied cord between two lights and using 14/2 instead of 12/2 between two lights? my original post has 12/2 from the switch to all but the last light which I jumped to with 14/2, all tied together and the wire is exposed, but now it has ti be changed?

k_buz 09-30-2012 08:15 AM

Because the lamp cord supplied with the undercabinet lights were approved by UL for certain specifications/uses. Those are stated in the instructions. There are probably special connectors that have to be used that came prefabbed on the cords as well. When you extend the circuit with your own 14-2 romex, you are giving the impression that this wiring is part of the house wiring and someone in the future can connect more lights/receptacles off this circuit. If more lights are connected, that lamp cord which may be as small as 16-2 now could have 20A of current running thru it causing a fire hazzard.

Jim Port 09-30-2012 08:17 AM

It may seem to be an issue of semantics, but the electric code is not written to allow the last portion of the circuit to be smaller like in your example.

Jim Port 09-30-2012 08:19 AM


Originally Posted by bobelectric (Post 1020037)
Read about tap rules. You are legal.

Could you please expand on how this would be legal?

k_buz 09-30-2012 08:19 AM

Also, consider if someone did connect to that last fixture to install say a shop light, that shop light will not be grounded. Your typical lamp cord does not carry a ground.

stickboy1375 09-30-2012 01:26 PM

12 Attachment(s)

Originally Posted by bobelectric (Post 1020037)
Read about tap rules. You are legal.


frenchelectrican 09-30-2012 05:26 PM


Originally Posted by bobelectric (Post 1020037)
Read about tap rules. You are legal.

Vous êtes sérieux ? :huh:

( You are serious ? )


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