LV wiring in wall for LED Lighting

[gravitydrno]

Working on a commercial restaurant where they want LED tape lighting on the underside of each shelf on a two shelf hanging wine display. I was hoping to mount the transformer in the crawl space (using a weatherproof transformer for extra protection) and enter the wall up to a dimmer then from the switch up inside the wall to a wood beam, run along the top and then down through the beam onto the display. Reading through 725 it is my understanding that since the secondary is 12v drawing 1.1a I am running a class 2 circuit and any CL2 wire would be compliant inside the wall and need not be in conduit. I want a small cable size and was looking for suggestions,would a 18/2 thermostat cable work in this situation and be compliant?

 

[hbiss]

Reading through 725 it is my understanding that since the secondary is 12v drawing 1.1a I am running a class 2 circuit

Mmmm no. It's a class 2 circuit only if it says Class 2 on the transformer or power supply. What you read in 725 IMO shouldn't be there because it causes confusion. The load does not determine the circuit class, it is determined only by the power source which will have a label indicating the class. If there is no label then it is assumed to be class 1 and you have to use a Chapter 3 wiring method.

-Hal

 

[PetrosA]

There are plenty of Class 2 power supplies you can use with your LED tape, and if it's a reputable brand of LED tape, they'll even be available from the same manufacturer. If you're concerned about moisture, you can always mount the power supply in a PVC junction box or use a weatherproof enclosure. I use 14/2 CL2 speaker cable for my LED installations. I don't think I'd trust 18/2 to protect me from voltage drop, especially if there's a chance they might add more tape later on.

The bigger problem I see in your plan is how you're expecting to dim the load side of a 12V power supply? That dawg ain't gonna hunt.

 

[gravitydrno]

Sorry I misstated, I know it's a class 2 circuit because I am using a class 2 transformer and THAT the voltage is 12v drawing 1.1a.

Petrosa- In rechecking the source (SuperbrightLEDS.Com) the tape is "UL Listed" but their transformer is "UL Recognized". This company offers a dimmer switch that states: Specifications:
Input Voltage : DC 12~24V
Output Voltage: DC 12~24V
PWM Dimming Range: 0% ~100% Maximum Load: 100W

I will be calling them for more information. and thanks for answering my question.

 

[hbiss]

Sorry I misstated, I know it's a class 2 circuit because I am using a class 2 transformer and THAT the voltage is 12v drawing 1.1a.

Petrosa- In rechecking the source (SuperbrightLEDS.Com) the tape is "UL Listed" but their transformer is "UL Recognized". This company offers a dimmer switch that states: Specifications:
Input Voltage : DC 12~24V
Output Voltage: DC 12~24V
PWM Dimming Range: 0% ~100% Maximum Load: 100W

Then it looks like you are good to go. 18/2 thermostat is CL2 and 18ga should be fine unless the length is long.

-Hal

 

[PetrosA]

Sorry I misstated, I know it's a class 2 circuit because I am using a class 2 transformer and THAT the voltage is 12v drawing 1.1a.

Petrosa- In rechecking the source (SuperbrightLEDS.Com) the tape is "UL Listed" but their transformer is "UL Recognized". This company offers a dimmer switch that states: Specifications:
Input Voltage : DC 12~24V
Output Voltage: DC 12~24V
PWM Dimming Range: 0% ~100% Maximum Load: 100W

I will be calling them for more information. and thanks for answering my question.

Ok, now I feel stupid. I've never seen a dimmer like that. I've seen cabinet mounted dimmers from Hafele, but that's a whole other beast. I wonder whether these can be mounted into an LV-1 or whether they need a box. They also don't seem to have a UL listing, but would they need it?

 

[hbiss]

Ok, I wonder whether these can be mounted into an LV-1 or whether they need a box. They also don't seem to have a UL listing, but would they need it?

That Decora style dimmer? CL2 doesn't need a box so a LV-1 should be fine. Don't think it needs a UL listing.

-Hal