Hard wired under cabinet fixtures


  #1  
Old 04-25-05, 04:22 PM
JohnF1444
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Question Hard wired under cabinet fixtures

I want to install under-cabinet flourescent fixtures (3 - 33" @18w and 1 - 18" 15w). I bought these today and want to 'hard wire' to a an outlet box and run them thru a central common switch.

I want to run the wire behind my drywall about 1" below my cabinets. I have studs every 16" or so, so I plan simply to notch out the drywall at the stud point and 'jump' it over. I don't want to rip out the wall and have to pass it in the stud by drilling a hole in it.

Most of these fixtures also come in a pre-wired version that simply has an 18 or 16 gauge lamp wire with a plug at the end so I figure I can use regular lamp wire or thicker low-voltage wire to accomplish the same thing. These are much more flexlible to 'fish' from one fixture to the next down to the outlet I want to grab the power from.

What wire should or can I use?
 
  #2  
Old 04-25-05, 05:19 PM
S
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Originally Posted by JohnF1444
I bought these today and want to 'hard wire' to a an outlet box and run them thru a central common switch.
This implies that you have a switched recepticle. Do you?


[/QUOTE]I want to run the wire behind my drywall about 1" below my cabinets. I have studs every 16" or so, so I plan simply to notch out the drywall at the stud point and 'jump' it over. I don't want to rip out the wall and have to pass it in the stud by drilling a hole in it.[/QUOTE]

This is illegal. The studs must be drilled and the wire passed through the holes.

[/QUOTE]Most of these fixtures also come in a pre-wired version that simply has an 18 or 16 gauge lamp wire with a plug at the end so I figure I can use regular lamp wire or thicker low-voltage wire to accomplish the same thing. These are much more flexlible to 'fish' from one fixture to the next down to the outlet I want to grab the power from.

What wire should or can I use?[/QUOTE]

On prewire fixtures, these are approved as a prepackaged unit, for use as a free standing or joined assembly with approved connectors and are not designed as "house" wiring.

You need to use a minimum of 14-3.
 
  #3  
Old 04-26-05, 12:59 AM
JohnF1444
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Hey Snoonyb!

1. Yes I have a switched recepticle. One switch for the run of flouresents.

2. Why is this illegal? The exposed slotted part of the drywall will be covered with ceramic tile once I am done and it (the slot and wire) is located 1/2" below the cabinits. No chance of ever nailing into it.

3. The units I bought do not have a prepackaged wire connected to them and are designed to be hard-wired. Why do I need 14-3? The ground? The prepacked kind do not have a ground or third wire. They use a regular 2-pronged lamp cord.

I am sure that my connections will work but I am now concerned about the 'low-voltage' 14-2 wire that I bought. The salesperson at the store said it would be OK since the fixtures are only drawing 67w total. What is the difference betweeen regular 14-2 and low-voltage 14-2?
 
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Old 04-26-05, 04:45 AM
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Originally Posted by JohnF1444
Hey Snoonyb!

1. Yes I have a switched recepticle. One switch for the run of flouresents.?
The practice is to bring the romex out of the wall at just below 54", which is the height of the bottom of the upper cabinets, in a standard installation. Which allows recepticle to be used for other appliances.

[/QUOTE]2. Why is this illegal?[/QUOTE]
Romex is required to be contained within the wall cavity with no less then 1 1/4"exposure to the wall surface. Where that cannot be maintained when crossing framing members through boring, a "DOTTIE PLATE" or nail plate is installed to protact the conductors from penetration.

[/QUOTE] The exposed slotted part of the drywall will be covered with ceramic tile once I am done and it (the slot and wire) is located 1/2" below the cabinits. No chance of ever nailing into it.[/QUOTE]
Wire lath or one of several backerboards are commomly used as substrait for ceramic tile, they require fasteners, be it nails, screws or staples and there in exists the opportunity for penetration.

[/QUOTE] Why do I need 14-3? The ground?[/QUOTE]
Yes. Within the direct wired units will be a black, white and a green wire. The green wire will be connected to the housing and is a mechanical ground, and that is the type you are using.

[/QUOTE]The prepacked kind do not have a ground or third wire. They use a regular 2-pronged lamp cord.[/QUOTE]
The prepackaged units will have in internal connection that uses the neutral as the safety device and are specifically designed as a plug-n-play unit.

[/QUOTE]I am sure that my connections will work[/QUOTE]
And I cannot advise you to accomplish this in any other than a method that is code acceptable.

[/QUOTE] but I am now concerned about the 'low-voltage' 14-2 wire that I bought. The salesperson at the store said it would be OK since the fixtures are only drawing 67w total. What is the difference betweeen regular 14-2 and low-voltage 14-2?[/QUOTE]
If it were just a matter of current draw, you could use 18-2, but it isn't. You are conduction 120V, it is high voltage, and using 14-2, it is not grounded.
 
  #5  
Old 04-28-05, 01:45 PM
Friedrich
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you would want to use 14-2 wire 14-3 is for use in a 3 way application. the "lamp cord" is usually a 14 gauge stranded wire and is not intended to be used in wall.

you also might want to notch out the stud and use a plate over the wire, so you don't drive a nail into the wire unintensionally.
 
  #6  
Old 04-29-05, 03:51 AM
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Originally Posted by Snoonyb
You are conduction 120V, it is high voltage, and using 14-2, it is not grounded.
Snooby, you have your cable designations are wrong. 14-2 contains three wires: black, white and bare (ground). It is more precisely called 14-2/g for "with ground".

14-3 contains 4 wires: black, white, red, and bare.

For this application, the OP needs 14-2.
 
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Old 04-29-05, 04:20 AM
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If you are tiling over this wall anyway, why not just do the job right and pull off enough drywall to drill the studs? Your patch job won't have to be very finely finished since you are covering with tile. Or you could pull of the drywall completely, run your wires, and replace with backerboard to get a more solid substrate for your tile.

You MUST use NM-B (Romex) inside a wall cavity.

Also, you may need to use 12-2 if the circuit you are tying into is a 20A circuit. Make sure you check! Under no circumstances can you use low-voltage wire in this application.
 
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Old 04-29-05, 04:24 AM
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As has been stated, you cannot do this.

For wire in walls (that carries 120 volts) you must use a minimum size of 14 gage. 14-2 with ground is appropriate if this is a 15 amp circuit.

You cannot notch studs. This makes them weaker, and it leaves the wire too close to the surface of the wall. Do it right. Drill holes through the center of the studs, or come up from the basement. If you are going to tile over the holes, you can make them larger.

I have no idea what you mean by low voltage 14-2 wire. 14-2 is 14-2. If it is properly sheathed cable then it is appropriate. If it is individual wires it is not appropriate. The comment about the low power requirement is allowing low voltage wire is ridiculous. No matter how much power these lights draw, they still use the same voltage, 120 volts.


The other question is, where do you intend to draw power from for these lights?
 
 

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