Code Compliant Cable Tray?

[CAM]

Since wire mesh basket tray first came to the US in the mid-90's, the standard practice for installing has been this:

Followed by this:

The installer starts with a straight 10' stick of tray then cuts it with bolt cutters then bends it into desired shape then uses bolts to hold it together for hanging.

In most cases, these are UL Classified parts and the UL label is specific as to the "cross-sectional area" of the tray (from 2008 NEC 392.7(B)) for use as an Equipment Grounding Conductor. After the field modifications, however, the cross sectional area is drastically reduced (in the case of the photos above reduced to .11 square inches although the label says a minimum of .20 square inches).

Most AHJ's I have spoken with on the subject say it is definitely a Code violation, but hasn't been enforced.

Additional potential violations:
1. Sharp edges - NEC 392.5(B)
2. Corrosion Protection (where cut) - NEC 392.5(C)
3. Rigidity (this flexes like flex conduit) - NEC 392.5(A)
4. Side Rails (cut and patched?) - NEC 392.5(D)
5. Fittings (is this a "fitting"?) - NEC 392.5(E)

Again, I haven't seen enforcement on this despite the fact that most AHJ's confirm it's a violation. I see this practice in virtually every commercial or industrial building and ALL new construction.

Considering the importance of cable tray systems, especially as Equipment Grounding Conductors, why do you think there is so little enforcement?

 

[Buck Parrish]

Although used for different voltages, it appears to have been designed for comunications cable. 24 volts or less.

 

[clausb]

My opinion is that this is not "cable tray" per the definition. This is more along the lines of "basket" and is not a "structural system" per the definition of cable tray in NEC 392

 

[CAM]

Cable Tray is Cable Tray

Cable Tray is Cable Tray

My opinion is that this is not "cable tray" per the definition. This is more along the lines of "basket" and is not a "structural system" per the definition of cable tray in NEC 392

Can you provide a Code reference illustrating the difference you see?

As I understand it, a basket tray is identical in form, fit, and function to any other tray type with the differences only being in the amount of metal each contains and the type of metal which dictates the current they can carry. A basket tray installed today for copper Cat6A cables can be used tomorrow for 500MCM 600VAC cables as long as a divider is installed.

 

[paul]

The cross sectional area is not reduced. Stop looking at the area of the bottom of the tray and look at the cross section.

Additional potential violations:
1. Sharp edges - NEC 392.5(B)
2. Corrosion Protection (where cut) - NEC 392.5(C)
3. Rigidity (this flexes like flex conduit) - NEC 392.5(A)
4. Side Rails (cut and patched?) - NEC 392.5(D)
5. Fittings (is this a "fitting"?) - NEC 392.5(E)

1. File
2. They recommend and sell in their catalogue some enamel spray and zinc.
3. It is actually quite rigid when installed correctly.
4. There are a variety of products they sell other than the couplings you show that can be used.
5. Is what a fitting?

 

[cadpoint]

Welcome to the Forum!

Nice first post right out of the gate.

It seems that you could have used 110.13 too, to state how incorrect of the equipment that got altered.
Having read the individual Articles I understand where your coming from.

But I think over all, most all of the work is sad, the fixes I see as are follows.

1. they could have cut closer to the transverse member and
....angle away from the bed of the tray.
2. A can of spray paint
3. & 4.& 5. Just more assembly for the various equipment that will make it one. Great do all that and still fail, fuel for the Inspector!

... It will sure make me think about it next time I'll spend time in front of it...

Thank for the Thoughts!

I'm not voting

 

[jim dungar]

Almost all of 392.5 is ttoo vague to enforce based on a picture of an item that has not been completely installed.

392.5(A) says the cable tray only needs to be 'strong' enough to support what is in it. This means that tray used to support Cat 6 comm cable does not need to be built and supported as that carrying 500kcmil.

392.5(B) says you can't have sharp edges that can damage insultation. If the conductors are bundled on the outside edge of tray, in your picture, they are not affected by the sharp edges.

392.5(C) This cable tray needs to be protected against corrosion just like any other metallic enclosure per 300.6, just like any filed cut in any ladder style tray needs to be.

392.5(D) If the tray has any type of side it meets this requirement.

392.5(E) If the manufacturer has UL classified components, it seems that they would satisfy the "other suitable" means.

392.7(B) says tray shall be permitted, but does not require it, to be a grounding conductor, therefore its whether or not its cross sectional area meets 392.7(B)(2) is optional.

 

[CAM]

Cross-Sectional Area of Basket Tray

Cross-Sectional Area of Basket Tray

The cross sectional area is not reduced. Stop looking at the area of the bottom of the tray and look at the cross section.

NEC 392.7(B)(a):  Total cross-sectional area of both side rails for ladder or trough cable trays; or the minimum cross-sectional area of metal in channel cable trays or cable trays of one-piece construction.

A tray made of continuous welded wire is considered a 1 piece tray for UL testing and the total area is calculated as the area of the longitudinal wires running continuously through the piece. If you cut the longitudinal wires then you have to make sure you have enough to continue to meet whatever cross-sectional area claimed on the UL label don't you?

 

[CAM]

Wire Basket Tray as Equipment Grounding Conductor

Wire Basket Tray as Equipment Grounding Conductor

392.7(B) says tray shall be permitted, but does not require it, to be a grounding conductor, therefore its whether or not its cross sectional area meets 392.7(B)(2) is optional.

Of course that's optional, BUT, here's the problem:

From UL's White Book:

This category covers cable trays intended for assembly in the field and for use in accordance with Article 392 of ANSI/NFPA 70, "National Electrical Code" (NEC). They have been Classified as to their suitability for use as equipment grounding conductors in accordance with Sections 392.3(C) and 392.7(B) of the NEC. The cable trays are marked on the outer surface of the sidewall of the tray indicating the cross-sectional area of the grounding metal.

So if the only basis of the "listing or labeling" is performance as an Equipment Grounding Conductor, any modification that alters that performance would be a violation wouldn't it???

 

[jim dungar]

Of course that's optional, BUT, here's the problem:

From UL's White Book:

This category covers cable trays intended for assembly in the field and for use in accordance with Article 392 of ANSI/NFPA 70, "National Electrical Code" (NEC). They have been Classified as to their suitability for use as equipment grounding conductors in accordance with Sections 392.3(C) and 392.7(B) of the NEC. The cable trays are marked on the outer surface of the sidewall of the tray indicating the cross-sectional area of the grounding metal.

So if the only basis of the "listing or labeling" is performance as an Equipment Grounding Conductor, any modification that alters that performance would be a violation wouldn't it???

All field modifications may 'void' the UL listing, even the field cutting of ladder type cable tray, the only people that can tell us is UL. If the AHJ has questions as to the suitability of a wire basket cable tray installation they should contact the listing agency for assistance.

If the tray is not being used as an EGC then the amount of cross sectional area is moot. Everything depends on how it is actually installed, not how it may someday be misused.

 

[CAM]

UL Role in Basket Tray vs AHJ Role

UL Role in Basket Tray vs AHJ Role

All field modifications may 'void' the UL listing, even the field cutting of ladder type cable tray, the only people that can tell us is UL. If the AHJ has questions as to the suitability of a wire basket cable tray installation they should contact the listing agency for assistance.

If the tray is not being used as an EGC then the amount of cross sectional area is moot. Everything depends on how it is actually installed, not how it may someday be misused.

The basic requirements for cable tray under NEC don't change depending on what cable or raceway is installed in it. The only variables dictating use are load capacity and ampacity for use as an Equipment Grounding Conductor right? And since load capacity is NOT subject to any NRTL verification this is just a big liability issue for the engineer and contractor rather than a Code issue.

The cross-sectional area is only moot if the UL label is also moot. Cross-section is the ONLY information printed on the label other than the manufacturer's name and UL logo.

Lastly, if you carefully real UL's position on Field Modification, they lay the liability for it on the AHJ. UL does have a Field Inspection program, but I've never seen it deployed. Again, 90%+ of the inspectors I have contacted on this issue have strongly stated that cut/bend basket tray installation is a Code violation and that the only remedy is UL approved fittings for changes in direction.

http://www.ul.com/global/eng/pages/offerings/perspectives/regulator/electrical/fieldcertification/fieldmodification/

 

[jim dungar]

392.7(B)(2) is the only code section I see that mentions the cross sectional area requirements. 392.7(B)(3) is the section that requires the tray to have a marked, or labeled, with its cross sectional area.

But 392.7(B) is an optional code section. If the tray is not being used as a EGC then there is no code violation.

UL labels only validate the state of the equipment when it shipped from the factory. Field installations always need to be acceptable to the AHJ.
For example, if a UL Type 12 industrial enclosure is field modified, by cutting a rectangular opening to accept a cable tray, its UL label has now been voided. But, the AHJ may still accept the installation if the 'environmental tightness' of a Type 12 is not required.

 

[roger]

Cam, what you are showing in your OP is basically what Hoffman includes with their instuctions for their wire mesh tray, see pages 8 and 9 of this document. With that being said, what is included in their instructions would permitt altering their tray and be allowed per 110.3.

Roger

 

[CAM]

110.3(B) Not Relevant

110.3(B) Not Relevant

Cam, what you are showing in your OP is basically what Hoffman includes with their instuctions for their wire mesh tray, see pages 8 and 9 of this document. With that being said, what is included in their instructions would permitt altering their tray and be allowed per 110.3.

Roger

Do a manufacturer's instructions override Code? If a manufacturer tells you to remove the circuit breaker and replace it with a coin is that okay? If a manufacturer tells you to cut your cable tray to shreds and bolt it back together is that okay?

110.3(B) Installation and Use. Listed or labeled equipment shall be installed and used in accordance with any instructions included in the listing or labeling.

Again, UL does NOT look at installation instructions for wire mesh basket tray. They look at cross-sectional area and splice hardware (if supplied - if not supplied UL assumes it will be done correctly). UL has not tested or approved anything like the modifications made in the photos I attached to my original post. Nothing like that is or can be listed or approved. There are no instructions included in the listing or labeling!

 

[CAM]

392.7(B)(3) is the section that requires the tray to have a marked, or labeled, with its cross sectional area.

And if that cross-section is changed by the installer would you then agree that the product is no longer correctly labeled? And isn't an incorrect or false label worse than no label or listing at all?

UL labels only validate the state of the equipment when it shipped from the factory. Field installations always need to be acceptable to the AHJ.

Are there not a multitude of products which require field assembly, in a prescribed manner, WITHOUT modification? If so, then it stands to reason that products modified would necessarily be treated differently than products not modified right? And since our friends at UL have no idea what the installer might do in modifying a listed or labeled product then it cannot stand behind that product's performance and it is then up to the AHJ to accept liability for himself or to red-tag the work.

For example, if a UL Type 12 industrial enclosure is field modified, by cutting a rectangular opening to accept a cable tray, its UL label has now been voided. But, the AHJ may still accept the installation if the 'environmental tightness' of a Type 12 is not required.

Exactly! And then it is no longer a Type 12 enclosure is it? The AHJ has assumed all liability for the injury or death that might result if the product then fails in a spectacular fashion.

 

[cadpoint]

....Exactly! And then it is no longer a Type 12 enclosure is it? The AHJ has assumed all liability for the injury or death that might result if the product then fails in a spectacular fashion.

If the Local AHJ adopts Annex H, 80.29, then no

 

[jim dungar]

And if that cross-section is changed by the installer would you then agree that the product is no longer correctly labeled? And isn't an incorrect or false label worse than no label or listing at all?

No, I would not.
The label says how the device was shipped not how it was installed.
The UL label also says it is a classified product, so it must be used as part of an overall assembly. So, the entire method of installation needs to be considered.

Are there not a multitude of products which require field assembly, in a prescribed manner, WITHOUT modification? If so, then it stands to reason that products modified would necessarily be treated differently than products not modified right? And since our friends at UL have no idea what the installer might do in modifying a listed or labeled product then it cannot stand behind that product's performance and it is then up to the AHJ to accept liability for himself or to red-tag the work.

I think there are many more products that require field modification than don't.

Exactly! And then it is no longer a Type 12 enclosure is it? The AHJ has assumed all liability for the injury or death that might result if the product then fails in a spectacular fashion.

Unless a device has integral threaded conduit connections, almost every installation of conduit requires field modification. The simple act of "punching" a hole in an enclosure must be acceptable to the AHJ. Even the removal of a factory knockout is not covered by the UL label, after all UL has no way of knowing if the enclosure was damaged/distorted in the field during the knockout extraction. The cutting of an enclosure may impact the UL Type 12 rating but it may not impact the Type 1 rating that is also on the label.

 

[iwire]

The simple act of "punching" a hole in an enclosure must be acceptable to the AHJ. Even the removal of a factory knockout is not covered by the UL label, after all UL has no way of knowing if the enclosure was damaged/distorted in the field during the knockout extraction.

For example I try to order all wireway, pull boxes and cabinets without any KOs at all so I have to make my own holes.

 

[roger]

Do a manufacturer's instructions override Code? If a manufacturer tells you to remove the circuit breaker and replace it with a coin is that okay? If a manufacturer tells you to cut your cable tray to shreds and bolt it back together is that okay?

The manufacturers instructions are in fact part of the code, once again 110.3

110.3
Installation and Use. Listed or labeled equipment shall be installed and used in accordance with any instructions included in the listing or labeling.

Again, UL does NOT look at installation instructions for wire mesh basket tray. They look at cross-sectional area and splice hardware (if supplied - if not supplied UL assumes it will be done correctly). UL has not tested or approved anything like the modifications made in the photos I attached to my original post. Nothing like that is or can be listed or approved. There are no instructions included in the listing or labeling!

Maybe you should start using Hoffman which includes instructions with their listed and labeled tray.

Roger

 

[CAM]

The manufacturers instructions are in fact part of the code, once again 110.3


Maybe you should start using Hoffman which includes instructions with their listed and labeled tray.

Roger

Really? And I read something very different in my copy

110.2 Approval.
The conductors and equipment required or permitted by this Code shall be acceptable only if approved.
FPN: See 90.7, Examination of Equipment for Safety, and 110.3, Examination, Identification, Installation, and Use of Equipment. See definitions of Approved, Identified, Labeled, and Listed.

And again, if the part has been field modified to the extent where the label is completely incorrect (ie claiming .20 square inches cross section when only .10 remains) you believe that's okay?