Code Compliant Cable Tray?

[jim dungar]

And you will note that their last entry, the one for the 90 degree kit, which requires cutting the tray IS NOT UL Classified!

Only one of their methods for making 90? bends is not UL Classified.
The method you posted in your original photos uses UL Classified splice plates.

I can not find anything in the NEC and our state code, that requires 'tray' to be UL Classified unless it is being used as an EGC.

 

[CAM]

I'll let them challenge NEMA then. Let me direct you to (and maybe you should show this to the AHJ's you say agree with you) page 32 and 33 of this NEMA document so regardless of the NEC allowing it so does NEMA

You will have to set up an account at the NEMA site, it's easy and free.

In short, you don't have to ask installers anything, you're real battle is going to be with NEMA and the NEC 110.3(B)


Roger

NEMA VE-2 is a voluntary standard that may or may not have any applicability on a job depending on the plans and specs. But since you mention VE-2, you should read the fine print on page 33 under section 4.7 and then the NOTE. Wire mesh basket tray, under the current VE-2, should not be used as an equipment grounding conductor because it is going to be cut/bent.

That is self-contradictory with the UL Classification of the product as an EGC.

It is a reflection of the FACT that NEMA is an *association of manufacturers* and it's standards are developed by majority vote. VE-2 concedes that wire mesh basket tray, when cut and bent, doesn't function under the one actual and impartial standard to which it could be compared (performance as EGC under NEC).

You might also know that the committee responsible for VE-2 meets this month to review the document and you can see the manufacturers who will be responsible for the content thereof at http://cabletrays.com/members.html

 

[CAM]

Only one of their methods for making 90? bends is not UL Classified.
The method you posted in your original photos uses UL Classified splice plates.

I can not find anything in the NEC and our state code, that requires 'tray' to be UL Classified unless it is being used as an EGC.

I challenge you to find anything from any major manufacturer claiming that what is shown in my original post photos will or remotely could pass UL testing.

While you're looking you will undoubtedly come across technical bulletins and installation instructions explicitly telling you NOT to do what the photos show if the tray will be used as EGC. And, again, UL looks ONLY at whether tray can perform as EGC - nothing else (at least in US).

If you have trouble finding relevant documents send me a private message with your email and I will email them to you.

 

[roger]

Having taken the weekend off and given this a little thought, I'd like to get my question back on track. I'm here for market research purposes primarily. And the market for wire mesh basket tray is 100% commercial and predominantly in big cities. The "commercial" electrical guys in the small town where I lived for the last 20 years wouldn't know a basket tray from a shelf.

And I've been around the block a time or two and know how unnecessarily and pointlessly argumentative most online forums are. This one seems a little better than most, but I still see some argument only for the sake of argument.

Is there anybody here who is an active engineer or commercial contractor (and here I am looking for PM's not inside wiremen - we all know the inside wiremen get stuck with whatever the PM chooses most of the time regardless of whether it's right or wrong) who uses or has used basket tray on a large job?

And for the sake of full disclosure, for those who didn't look at my profile to see where my interests are, I am on the sales side of the business for a manufacturer. I have a deep understanding of what it takes to develop a product, get it through UL, and get it to market successfully. I also have around 10 years experience on the commercial side of electrical contracting in business development roles.

I'm interested in all constructive opinion, but if you're a residential electrician in farm country please don't argue about the Code applicability or how UL evaluates products - it's not helping anybody.

Have you even taken the time to look at the profiles of those in this thread?

There are engineers and PM's replying to you in this thread, I am a PM for a fairly large company with offices in two states, one of my current projects has more than 7,000 feet of wire mesh tray.

We install tray of all types regularly.

Roger

 

[CAM]

Have you even taken the time to look at the profiles of those in this thread?

There are engineers and PM's replying to you in this thread, I am a PM for a fairly large company with offices in two states, one of my current projects has more than 7,000 feet of wire mesh tray.

We install tray of all types regularly.

Roger

Excellent, then you will be directly effected if your AHJ is paying attention. And this goes right back to my original post and question: why have they not paid attention in the past? Every one I have spoken with or corresponded with has said what my photos show is a violation, but the few I thought to ask about why it's been allowed to continue for a decade could only say, "it's telephone wire and we haven't paid much attention."

But what is today used as a pathway for "telephone wire" is still a cable tray and still allowed for all the different cable types listed in 392.3(A). So when that "telephone wire" is removed because it's abandoned and isn't permanent plenum rated the tray sits empty until somebody needs it for electrical service. Then it carries 500mcm energized to 600V and 400A or more. Then what was overlooked becomes deadly.

 

[roger]

NEMA VE-2 is a voluntary standard that may or may not have any applicability on a job depending on the plans and specs. But since you mention VE-2, you should read the fine print on page 33 under section 4.7 and then the NOTE. Wire mesh basket tray, under the current VE-2, should not be used as an equipment grounding conductor because it is going to be cut/bent.
That is self-contradictory with the UL Classification of the product as an EGC.

No big deal, most designers specify grounding jumpers on tray, so with this being the case, using the tray as an EGC isn't much of a concern, and in my case most wire mesh tray is only used for LV wiring.

It is a reflection of the FACT that NEMA is an *association of manufacturers* and it's standards are developed by majority vote. VE-2 concedes that wire mesh basket tray, when cut and bent, doesn't function under the one actual and impartial standard to which it could be compared (performance as EGC under NEC).

You might also know that the committee responsible for VE-2 meets this month to review the document and you can see the manufacturers who will be responsible for the content thereof at http://cabletrays.com/members.html

And the group that voted for the document are the same ones that will be there.

Is the company your associated with in the group.

Roger

 

[roger]

Excellent, then you will be directly effected if your AHJ is paying attention. And this goes right back to my original post and question: why have they not paid attention in the past? Every one I have spoken with or corresponded with has said what my photos show is a violation, but the few I thought to ask about why it's been allowed to continue for a decade could only say, "it's telephone wire and we haven't paid much attention."

The inspectors here definitely pay attention and they know that this is not a problem.

But what is today used as a pathway for "telephone wire" is still a cable tray and still allowed for all the different cable types listed in 392.3(A). So when that "telephone wire" is removed because it's abandoned and isn't permanent plenum rated the tray sits empty until somebody needs it for electrical service. Then it carries 500mcm energized to 600V and 400A or more. Then what was overlooked becomes deadly.

After it is installed for a particular use, if it is changed later it would be up to the installer to make sure any deficiencies are corrected before it used for something else. For example, I install a 200 amp fusible disconnect with 150 amp fuses for a particular load, if somebody comes after that to replace the load and upgrade the fuses to 200, it would be their responsibility to verify all the wiring is correct.

Roger

 

[jim dungar]

...this goes right back to my original post and question: why have they not paid attention in the past?

Probably, because the tray is not being used as an EGC.

None of the wire mesh tray installations I have been involved with used the tray as the EGC, therefore no violation of anything.

 

[iwire]

But what is today used as a pathway for "telephone wire" is still a cable tray and still allowed for all the different cable types listed in 392.3(A). So when that "telephone wire" is removed because it's abandoned and isn't permanent plenum rated the tray sits empty until somebody needs it for electrical service. Then it carries 500mcm energized to 600V and 400A or more. Then what was overlooked becomes deadly.

What if an installer decided to reuse the "telephone wire" for line voltage?


As far as the cable tray it would be up to the installer and inspector of the 500Kcmil conductors to make sure the tray is suitable for the new use.

 

[CAM]

What if an installer decided to reuse the "telephone wire" for line voltage?


As far as the cable tray it would be up to the installer and inspector of the 500Kcmil conductors to make sure the tray is suitable for the new use.

Is "telephone wire" defined as being suitable for line voltage? Because the cable tray, by definition, is.

There is no such thing as "low voltage cable tray". It does not exist as far as either NEC or UL. Cable tray is cable tray. The differences between aluminum ladder, center rail, trough, and basket are span (capacities unverified by UL) and ampacity (verified by UL).

If the tray is existing, why would it be inspected? And if it had already been approved by an inspector when originally installed that might be the one case where, as a contractor, it would pay to argue with an inspector. "You (or somebody in your office) approved it and I am simply using it for one of it's intended uses per NEC when I install my 500mcm tray cable."

 

[CAM]

No big deal, most designers specify grounding jumpers on tray, so with this being the case, using the tray as an EGC isn't much of a concern, and in my case most wire mesh tray is only used for LV wiring.
Roger

Jumpers aren't going to help if the guts of the tray have been removed mid-span. Bonding Jumpers are required by 392.6(A).

And, great segue, 392.6(A) also requires:

Field bends or modifications shall be so made that the electrical continuity of the cable tray system and support for the cables is maintained.

Now has anybody ever seen load ratings for basket tray with the longitudinal or rib wires cut out? Obviously, if you remove the side longitudinal wires and can then hand bend the tray the capacity has been vastly diminished. So too if you cut the longitudinal wires and then use splice-washers to patch it back together. There are no load ratings published because they would be so ridiculously low that nobody would ever consider hanging anything from it.

And the group that voted for the document are the same ones that will be there.

Is the company your associated with in the group.
Roger

Almost, there have been some membership changes since last publication. And aren't you the one who chastised me for not reading the profiles here? Unlike most everyone else's, mine actually says where I work and that would lead you to the obvious answer to your question. We do support NEMA (it has the potential to do very good things for our very young market segment) and I am the technical committee member from our organization (meaning I vote on standards).

 

[CAM]

Odd - no reply?

Odd - no reply?

I challenge you to find anything from any major manufacturer claiming that what is shown in my original post photos will or remotely could pass UL testing.

While you're looking you will undoubtedly come across technical bulletins and installation instructions explicitly telling you NOT to do what the photos show if the tray will be used as EGC. And, again, UL looks ONLY at whether tray can perform as EGC - nothing else (at least in US).

If you have trouble finding relevant documents send me a private message with your email and I will email them to you.

How very odd that nobody has come up with anything in response to this direct challenge...

 

[roger]

There is no such thing as "low voltage cable tray". It does not exist as far as either NEC or UL. Cable tray is cable tray. The differences between aluminum ladder, center rail, trough, and basket are span (capacities unverified by UL) and ampacity (verified by UL).

I may have missed it, where did anyone say there was "low Voltage Tray"?

If the tray is existing, why would it be inspected?

Have you ever been involved with renovations?

And if it had already been approved by an inspector when originally installed that might be the one case where, as a contractor, it would pay to argue with an inspector. "You (or somebody in your office) approved it and I am simply using it for one of it's intended uses per NEC when I install my 500mcm tray cable."

And after seeing you istalled bonding jumpers around the field modification the inspector would sign off again

Roger

 

[CAM]

I may have missed it, where did anyone say there was "low Voltage Tray"?
Roger

in my case most wire mesh tray is only used for LV wiring.
Roger

<p>
<p>

And after seeing you istalled bonding jumpers around the field modification the inspector would sign off again
Roger

So you concede the point that there is a danger to cutting/bending where you remove enough metal so the label is no longer accurate? Why else put a band-aid over that section?

And how many inspectors have you come across who don't care about UL labeling? I have had inspectors demand UL labels on items like a rack shelf for a 19" TIA equipment rack.

 

[iwire]

Is "telephone wire" defined as being suitable for line voltage? Because the cable tray, by definition, is.

OK point taken, but not all tray is suitable for grounding.

If the tray is existing, why would it be inspected?

If I was instilling 500 Kcmil conductors in a building using existing infrastructure you can bet there would be an inspection. To even suggest otherwise tells me you have not been in the field working with inspectors.

And if it had already been approved by an inspector when originally installed that might be the one case where, as a contractor, it would pay to argue with an inspector. "You (or somebody in your office) approved it and I am simply using it for one of it's intended uses per NEC when I install my 500mcm tray cable."

I can tell you with certainty that tray in your pictures would not pass inspection if converted from 'phone wire' use to power wiring use.

 

[iwire]

How very odd that nobody has come up with anything in response to this direct challenge...

I guess you got us then, we did not step up, or is it that you have not read the responses?

From Jim

Cable tray is not a UL Listed item, it is only UL classified. As such it is not a standard alone product and must be used with other UL devices. At least one manufacturer (Cooper B-Line) shows how many splice kits are required for their UL classification.
http://www.cooperbline.com/pdf/Flyer...ed-Splices.pdf
pages 2 and 3.

 

[roger]

How very odd that nobody has come up with anything in response to this direct challenge...

Well, the problem is, until someone agrees with you, you will not listen to any reasonable counterpoint to your's, so why should anyone bother?

Now, why haven't you answered the following direct questions?

Once again, what is your real issue with this? Can you provide some documentation that shows catastrophic events, personal injury, property damage, or death that can be contributed to this practice?

There are more in this thread you haven't answered as well? Then you take cheap shots at demeaning the members here in your post # 40 taking the position that unless they work in some large commercial or industrial capacity they are wasting your time. I would say you would be praising these same people if even one came forward to back your position.

Now,

And I've been around the block a time or two and know how unnecessarily and pointlessly argumentative most online forums are. This one seems a little better than most, but I still see some argument only for the sake of argument.

Back to my opening sentence in this post. :grin:



Roger

 

[CAM]

If I was instilling 500 Kcmil conductors in a building using existing infrastructure you can bet there would be an inspection. To even suggest otherwise tells me you have not been in the field working with inspectors.

I can tell you with certainty that tray in your pictures would not pass inspection if converted from 'phone wire' use to power wiring use.

Ah, but you are a conscientious guy and Codes weren't written for guys like yourself. They were written for the morons who would do everything as cheaply and as dangerously as possible if the Code and enforcement did not exist.

Now let's make a list of all the times when one of *those* guys could get some line voltage into that existing pathway *without* inspection or with absolute bare minimum inspection..

THAT'S the problem. As an engineer said to me during discussion (unrelated to this) about a competitor's products - "it's not stupid-proof enough". Meaning if you don't remove every possible way for "stupid" to electrocute himself - he will electrocute himself.

And what most here are doing is saying, "Okay, let's have two *classes* of cable tray. One will be legacy type for line voltage and one will be basket which *can* be used for line voltage if installed correctly but will be mainly for LV and there it doesn't matter so much how it's installed."

You are smart enough to tell the difference and deal with each properly and safely. And I will bet the farm you know hundreds if not thousands of guys who aren't that smart.

 

[roger]

I may have missed it, where did anyone say there was "low Voltage Tray"?
Roger

in my case most wire mesh tray is only used for LV wiring.
Roger

<p>
<p>

Go back and read again, I said "in my case most wire mesh tray is only used for LV wiring" I never said it was only used or listed for LV wiring did I? If you are going to use a quote try to read it in full.

And after seeing you istalled bonding jumpers around the field modification the inspector would sign off again
Roger

So you concede the point that there is a danger to cutting/bending where you remove enough metal so the label is no longer accurate? Why else put a band-aid over that section?

Not at all, I also don't see bonding around plumbing fittings as being a band-aid fix.

And how many inspectors have you come across who don't care about UL labeling? I have had inspectors demand UL labels on items like a rack shelf for a 19" TIA equipment rack.

Depends on where you are, in NC all electrical items must be listed so heck, this might end up not being an issue in any capacity here in NC, it may be outlawed altogether, see NC GS 66-25

Roger

 

[jim dungar]

How very odd that nobody has come up with anything in response to this direct challenge...

What relevant documents are there for installations that do not use the tray as an EGC?

392.2 says that the primary function of cable tray is "a structural system used to securely fasten or support cables or raceways".

392.3(C) allows, but does not require, tray to be used as an EGC if the conditions of 392.7 are met.

392.7(A) requires metallic trays to be grounded the same as all other conductor enclosures per 250.96(A), if they are grounding conductors, or 250 Part VI, if the they are not grounding conductors.

392.7(B) are the requirements that must be met if the tray is intended to be an EGC.

I am still looking for the code that requires the tray to be 'UL labeled'. 392.3 simply requires the tray to be "identified".

The UL White book says their classified label on the cable tray is only applicable if the tray is being used as an EGC.

UL Classified items have only been labeled for specific applications and/or installation conditions. This means that every use and reuse of cable tray needs to be fully evaluated to see if the installation meets the conditions under which the items were classified.

If the tray is not an EGC, the UL label is meaningless.