Question about Lutron 7-C cable for Motorized Shades

[Tim Shady]

Hopefully someone can help me shed some light on this or lead me in the right direction. The now one generation older Lutron QED motorized shading system uses a 7 conductor (2) 16AWG (5) 18AWG cable, Liberty Cable markets it as their Lutron-RED brand. The motors use 24VDC, but are fed 24VAC from the 10 motor power panel (which runs on 110VAC) through a 3A circuit breaker (for each motor), down through 2 conductors (16AWG) in the cable to the motor where it is rectified into 24VDC to run the motor and/or a wall keypad.

The specification on the Liberty Lutron-RED is show here:
https://secure.libertycable.com/prod_details.php?pitem=LUTRON-P-RED
(click on the specification tab)

Summary here:
LIGHTING CONTROL: LUTRON SIVOIA QED 18/4 stranded twisted shielded + 16/2 stranded twisted + 18/1 stranded 300V CL3 jacketed .340 OD

So you can see that the wire is rated at 300V and does run low voltage AC power.

My question is if I can run 110VAC on this wire to run 110VAC Shade Motors? The 110VAC Somfy shade motors range from 1A to under 2A depending on lift capacity. Also shades typically do not run more than 30 seconds up or down, if that makes any difference.

The job is in Las Vegas, NV, but we do work nationwide so I am curious if something in the NEC will allow what I am asking (realizing that it still may not satisfy the inspector).

I want to make sure I am safe, clean, and legal. Other shading companies have approved and recommend using the Lutron Cable with 110VAC, but I am not so sure and Liberty isn't very sure either. Do you think I could ask the LV Electrican Inspector or some other official body if the answer isn't found here?

Thank you very much for your help. -Tim

 

[texie]

Far as I know (I've done a few) the 120 volt Somfy units require a Chapter 3 wiring method. The Lutron cable would not be suitable for Chapter 3 methods. I'm sure lots of the LV guys out there would say they use it all time. I've seen lots of scary shade/shutter installs that would never pass an inspection.

 

[hbiss]

That cable is CL3 and unless there is a power supply for those shades that has "class 3 wiring may be used" printed on it the answer is no. I'm sure there is no power supply and the power is taken right from the line. So you must use a chapter 3 wiring method.

-Hal

 

[Dennis Alwon]

I have used liberty cable for window drapes but I don't remember the voltage of the motor. I am sure the cable is listed for the use. I did a Lutron grafik eye system for lighting and the cable was listed for 120v and low voltage- looks a bit like the one shown.

 

[Tim Shady]

I have used liberty cable for window drapes but I don't remember the voltage of the motor. I am sure the cable is listed for the use. I did a Lutron grafik eye system for lighting and the cable was listed for 120v and low voltage- looks a bit like the one shown.

If it was Lutron motors you installed then they were most likely 24VDC or 24VAC.

I appreciate your responses it has helped cement this for me (and shown that one of our competitors is wrong in promoting it) that the cable cannot be used with higher voltage. I guess in order to run 120VAC the cable would have to be rated for 600V and not just the 300V it is rated for, aside from all of the other things you have pointed out.

Thanks again.

 

[hbiss]

I guess in order to run 120VAC the cable would have to be rated for 600V and not just the 300V it is rated for...

Well in a word-no. The voltage rating for CL2 and CL3 listed cables isn't printed on the jacket for a reason and that is so people won't think it is actually suitable for use at those voltages. In other words you are not supposed to consider the voltage rating of the those cables.

While there is flexible cordage like SJ cord, It cannot be used for fixed wiring. There is no cable that can be used for fixed wiring at 120 volts. You have to use a Chapter 3 wiring method unless the 120 volts is derived from a power supply that allows CL3 or CL2 wiring.

I am sure the cable is listed for the use. I did a Lutron grafik eye system for lighting and the cable was listed for 120v and low voltage

I don't think so unless the cable is part of a factory assembly all of which is approved.

-Hal

 

[Dennis Alwon]

If it was Lutron motors you installed then they were most likely 24VDC or 24VAC.

I appreciate your responses it has helped cement this for me (and shown that one of our competitors is wrong in promoting it) that the cable cannot be used with higher voltage. I guess in order to run 120VAC the cable would have to be rated for 600V and not just the 300V it is rated for, aside from all of the other things you have pointed out.

Thanks again.

If the voltage is 120V why would the cable need to be listed for 600V?

 

[texie]

If the voltage is 120V why would the cable need to be listed for 600V?

I don't believe that just because it is 300 volt rated it is an approved cable/wire type/size for chapter 3.

 

[hbiss]

If the voltage is 120V why would the cable need to be listed for 600V?

Again, the voltage rating of a CL3 or CL2 listed cable is not to be used to determine it's use.

-Hal

 

[Tim Shady]

I guess in order to run 120VAC the cable would have to be rated for 600V and not just the 300V it is rated for, aside from all of the other things you have pointed out.

This is what Liberty Cable told me, and also why I came here to ask the experts as I knew there was more to it.

So it is really about the wiring method, (and this may not be possible but for the sake of discussion), if the Lutron cable had been run in accordance with Chapter 3 then we could discuss if the cable could handle the current, but since it wasn't run in accordance with Chapter 3 wiring methods then it would fail inspection based on that alone. If Chapter 3 was somehow overlooked then it would still likely fail inspection due to the Class of the cable, etc.

Thank you for the education.

 

[hbiss]

So it is really about the wiring method

Exactly. A CL3 cable (it is actually a CL3 wiring method) can only be used with a CL3 (or CL2) source. Power and light must use one of the more stringent Chapter 3 wiring methods. The only way I could imagine someone attempting to install a CL3 cable as Chapter 3 is in raceway but that doesn't change anything. It's still a CL3 cable- in a raceway.

-Hal