NM Raceway?

[tom25]

Re: NM Raceway?

The cable fill chart is part of the listing, we also have a calculation chart to calculate for combinations of cables. The 40% was something that I wanted due to heat dissipation.
An example of one of the temperature test:

38-14/2 NM cables (40%)installed in the system with
12 amps on every conductor.(80% of overcurrent device) 912 amps flowing through the system without over heating the conductors or the product.
The verbiage has been changed to state that it was tested to 80% of the overcurrent device.

 

[don_resqcapt19]

Re: NM Raceway?

Tom,
In my opinion the listing has no effect on the code rules. The derating rules for more than 3 current carrying conductors still apply to the product. You need to submit a change proposal with the UL test results if you want installers to be able to use this product without derating.
Don

 

[websparky]

Re: NM Raceway?

Tom,

How can the "cable fill" apply to this product which is listed as "The UL category is UL 2239,
Hardware For The Support Of Conduit, Tubing, And Cable." when it isn't listed as a cable tray or conduit?? You are mixing the code references to fit your sales pitch.

How do you get around 2002 NEC 310.15 (B)(2)(a) and how do you explain 14AWG NM - 40% reduction of 25A = 10A when installed stacked or bundled longer than 24 in. ??

How about some actual UL listing proof!! I'm not asking for any trade secrets, just proof that your product is listed by UL as you suggest it is.

 

[George Little]

Re: NM Raceway?

The product in question is an excellent product and I've been very impressed with it's quality and ease of installation. The Listing of the product is very different and doesn't really fall in the standard wiring methods of wiring as we typically think of them. The limited use (1 & 2 family) is probably due to the fact that it wouldn't be suitable for conductors under continous load. If any person needs addition information they can contact UL and I'm sure the Listing can be verifyied.

As an inspector, I am a sceptic by nature and this product get's approved in my area (Michigan).

 

[tom25]

Re: NM Raceway?

Remember we are talking about (1&2 family).
I agree the NEC needs to change as new products are developed, and technology changes.
Quote : "The road to success is always under construction"
The state of Wisconsin has had an exception to the derating for 1&2 family for more than 20 years.

With a product like this, there has to be peramiters on fill to reduce confusion, and possible overheating.
At 40% fill, any combination, 80% of each overcurrent device, this product will not overheat with continuous loads, (as tested)
In a dwelling you will never see a load like that.
Look at exception (5)of 310.15 for MC cable.
If someone wanted to list bored holes, they would have to come up with a fill chart, then the product would be tested to the chart.
As of now, I often wonder how many 14/2 NM cables can be installed in a 3/4" bored hole or a 4"x6" homemade box installed on the bottom of the joists. How many cables can be installed under a staple?
UL Category 2239 products are tested as per the installation instructions submitted by the manufacture. This product is not a cable tray, non-metallic raceway etc. due to the open top, and is listed only for cable types NM,UF, and SE/SER.

I will not post the UL test on any website.
Read your PM's.

The product is listed for it's application.
With todays manufactured lumber, no structural integrity is lost.

I have a question:
How many times have you seen a big box store with EMT painted white in the ceiling, or a night club with the ceiling painted black?
Where in the NEC is that allowed? What other type of derating can be enforced due to the paint and the lack of heat dissipation?
I have seen temperature tests with painted EMT, and was surprised by the results.
1/2" EMT 3-phase circuit in a white, black, and unpainted piece of EMT.
Which one recorded the hottest temperatures?
The white one, the black ran the coolest.
White paint insulated the EMT, while the black was a heat sink and wicked the heat.

 

[don_resqcapt19]

Re: NM Raceway?

Tom,
That is fine that Wisconsin has a rule that permits the use of this product, but without such a rule the code derating rule applies. The UL testing and listing does not change the code rule. Until you get the code rule changed to allow the use of this product, its use, without applying the adjustment factors in Table 310.15(B)(2)(a), is a code violation.
Don

 

[tom25]

Re: NM Raceway?

Don

I understand the difference between the NEC and a UL listing. As an AHJ I'm open minded to change and when I see a product that has been evaluated
for it's installation (by a testing laboratory) and installed in the manner it was tested and listed, I don't see a problem. (my opinion)
The NEC is constantly changing trying to keep up with our changing industry ,but that is every 3 years.
This product is basically bridal rings with a cover.

Tom

 

[iwire]

Re: NM Raceway?

Originally posted by tom25:
I understand the difference between the NEC and a UL listing. As an AHJ I'm open minded to change and when I see a product that has been evaluated
for it's installation (by a testing laboratory) and installed in the manner it was tested and listed, I don't see a problem. (my opinion)

Tom now I am confused.

"I'm open minded to change" does this mean you let code violations slide if you feel it's OK? The NEC is just behind the times.

An in use cover is UL listed for use in a wet location. Does that mean I can install it in a shower space?

It's UL listed for that type of use but the NEC still will not allow it.

 

[LarryFine]

Re: NM Raceway?

Originally posted by tom25:
I have a question:
How many times have you seen a big box store with EMT painted white in the ceiling, or a night club with the ceiling painted black?
Where in the NEC is that allowed?

Just to play devil's advocate, where is it prohibited?

I would like a UL PM.

 

[websparky]

Re: NM Raceway?

Tom,

UL did not test your product and does not have anything to do with your home-made tests and your home-made conductor fill chart.

According to the NEC, when we use the calculations for NM square inches, we find that your chart is way over-stated. Maybe you could show us the math you used to determine conductor fill?

George Little,

As an inspector, I am a sceptic by nature [Smile] and this product get's approved in my area (Michigan).

It is not a matter of getting the UL listing information, that is published in the UL Books. What UL does not publish is the claims that Tom makes and provides with his product. The claims are mis-leading and do not line-up with the NEC.
By the way George and Tom, if this product was such a wonderful item as you both claim, and has been around for a few years now, why is it that it is only used and sold in certain locations around the country?? Why does it draw so much negative attention from many locations?? Why does Tom need to travel from state to state and attend inspector meetings to try and "sell" this product?? Don't get me wrong, the product is a very good product. I like the idea and the ease of installation. It saves a lot of time. However..... it is not immune to the NEC.