Kitchen - under cabinet low voltage lighting


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Old 04-04-07, 12:08 PM
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Kitchen - under cabinet low voltage lighting

As part of a kitchen remodel (that will include all new wiring and additional circuits) I will be installing low voltage counter lighting under the new cabinets. I want to install it in a way that avoids mounting a plug-in transformer under the cabinet. (I have a sofit above so cannot place it on top of the cabinet.)

My preference is to install the transformer in the joist space of the utility room below the kitchen and run low voltage wires in the stud space to the under cabinet lighting. The longest run would be 12 to 15 feet.

What is the best approach to running low voltage wiring in a wall space?

I was considering using plenum rated wire and using flexible plastic conduit (used for electronic cables) in the wall space.

Thanks in advance.

DavidJ
 
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Old 04-04-07, 02:25 PM
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I believe low voltage wires do not require anything specific regarding code, but if there are, I will be corrected shortly.

What voltage does this transformer swap it too 120 - 12-24v?

You could most likely run this however you want, in plastic conduit or not.
 
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Old 04-05-07, 08:26 AM
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You can't use a flexible cord as the fixed wiring in a structure.
Which means that you can't (without restrictions) run them inside a wall.

What is the operating voltage, wattage and number of fixtures that you want to connect to the transformer(s)?

Just because it's "low voltage" doesn't mean that it can't start a fire.

It's easy to overload a conductor using a low voltage supply.
This could result in a "hot" conductor inside your wall.

Post back with more info.
steve
 
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Old 04-05-07, 09:24 AM
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Thanks for the responses.

The lights will be 12 volt. Approximately 10 lights at 20 watts each.

I think my question should be rephrased to...

What type of cable should I use in a wall space to provide power from a transformer to low voltage under cabinet lighting? Does the cable need to be protected by conduit?

I am assuming that this is allowed as long as I use the correct cable type.

DavidJ
 
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Old 04-05-07, 09:37 AM
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David,

As long as it is allowed in your area you could run a Chapter 3 wiring method like non-metallic cable from the transformer output up the wall. Once it emerges from the wall splice it to the low voltage cables.

What lighting system are you using?
 
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Old 04-05-07, 10:14 AM
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The lights are xenon bulb, 12 volt 20 watt puck style lamps.

http://www.ylighting.com/mod88brrounb.html

My issue is that I want to place the transformer in the utility room below the kitchen so I need to run low voltage wiring in the wall to the fixtures. Also have cabinets that are separated by a window so need to run wire in the wall between them.

Could you be a bit more specific on Chapter 3 wiring?

THanks,

DavidJ
 
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Old 04-05-07, 12:13 PM
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10 lights at 20 watts each is 200 watts. Make sure your transformer is rated for at least this much.

200 watts at 12 volts is about 17 amps. So you need at least 12-gauge wire. I suggest you simply run 12/2 NM-B cable.
 
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Old 04-05-07, 01:16 PM
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The transformer is 250 watt so there is plenty of capacity and it will be fed by #12 wire on a 20 amp circuit.

My question is running the low voltage cable from the transformer (mounted in the joist space below the kitchen) to the individual lights.

What type of cable should I be using and should it be protected?

The cable that the manufacture provides is suitable for surface mounting under the cabinet but I certainly do not want to run it in the wall space unless it is protected by conduit or is a different cable type that is designed to be placed within a wall.

Thanks for the replies.

DavidJ
 
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Old 04-05-07, 01:50 PM
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And my answer was also about the low voltage cable downstream from the transformer.

The low voltage cable will be carrying ten times the current of the high voltage cable, so it needs to be pretty heavy.

This ain't no doorbell. You cannot use small wires. Use 12/2 NM-B.
 
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Old 04-05-07, 02:10 PM
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That is what I wanted to hear.

I will find some kind of enclosed terminal block to mount under the cabinet that will allow for the transition from #12 to the #18 cable that feeds the individual lights.

Thanks for the help.

DavidJ
 
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Old 04-05-07, 04:33 PM
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You may use plenum rated low voltage cable. #12 Min. (available at all supply houses).

The way I do this type of install, I run 1 cable from each fixture back to the trans. location. This allows the individual cables to only carry the current of 1 light. And makes a neat connection at each fixture.

no problems remotely locating the transformer. Pay attention to the wire length limitations, If any exceed it, enlarge the cable to # 10.
 
 

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