UL 758 (AWM) Wire in NEC Installation 4

[dtn6770]

Does the use of UL 758 (AWM) wire prohibit claims of NEC compliance?

I work at a compressor packaging company and am engaged in what is essentially a review our our design and assembly practices. There's generally held belief that our electrical and control systems comply with NEC even though there isn't a electrical engineer on staff. Our electrical systems are pretty simple: 24vdc power with basic control wiring to and from panels.

Despite my admittedly limited reseach and understanding, I'm campaigning to NOT make NEC compliance claims for several reasons. The one reason on topic is our use of AWM wire in instrument and control circuits. In the NEC I can find references to the MTW, THHN, and THWN wire we use in power circuits but no mention of AWM.

There's a lot of text printed on the insulation other than AWM, like CSA 208394 but I haven't been able to decipher its meaning. CSA is referenced a lot wrt the engines we use and I understand it to have some parallel function to the NEC, parallel but not equal.

Anyway, this post is just a sanity check on my position and I thank you in advance for your feedback.

 

[dpc]

If you are producing an engineered package assembly, NEC compliance may not be an issue. NEC applies to field wiring.

Does your equipment or control panel have a UL label? If so, I wouldn't worry about NEC.

 

[dtn6770]

The panels we purchase are NEMA 3 and are built and tagged as being CSA compliant for Class 1, Group D, Division 2 hazardous areas.

I agree that NEC compliance probably isn't required; my position is in opposition to folks that want to say our product is NEC complant. Basically, I don't want us to say it if it isn't true.

If I make my case, I fully expect I'll have to entertain follow up questions along the lines of how to achieve NEC compliance since people want to use it as a selling point, applicable or not.

Right now I'm gathering ammunition to illustrate why we're not NEC Compliant. The AWM wire is just one gap I'm trying to confirm.

 

[dpc]

AWM is not mentioned in the NEC - at least the 2002 version that I can search electronically.

I don't think "AWM" used by UL is referencing a single type of wire, but rather a group of wiring insulation types that listed as "Appliance Wiring Material".

There should be another designation for the wiring other than AWM.

 

[dtn6770]

I scored the answer to my question on UL's FAQ site.

1 - What is the relationship between the UL Standards for Wire and Cable and the National Electrical Code?

The large majority of UL's wire and cable Standards are intended to be compatible with the installation requirements of the National Electrical Code (NEC). Some exceptions are Boat Cable, Marine Shipboard Cable, and Appliance Wiring Material.

Tada...

 

[stephenw22]

If the CSA you refer to is the Canadian Standards Association, then it's the Canadian equivalent of the NEC. Even though the CSA and NEC standards may be similar, having CSA approval does not guarantee NEC approval, and vice-versa.

 

[dtn6770]

Canadian standards Association, yes. Agreed, not equal to NEC.

It looks like the CSA has a wider base than the NEC. That is the CSA appears to dabble in more than just electrical related issues.

 

[stephenw22]

The Canadian Standards Association is a massive group. An organization like the CSA might be better compared to the ANSI or ISO. There is one division of the CSA that is specifically dedicated to electrical standards, and they publish the CEC (Canadian Electrical Code). They also certify all electrical equipment in Canada.

 

[waross]

As stephenw22 says, CSA, Canadian Standards Association is not limited to electrical standards.
The CSA publishes the Canadian Electrical Code part 1, which is parallel but not equal with the NEC.
The CSA also publishes other specific electrical codes.
respectfully

 

[dtn6770]

Thanks everyone...

CSA & NEC parallel, not equal...my original and 4th post (I get it)

AWM not mentioned in NEC...my original post

CSA more than just an electrical post...my 4th post

answer to my own original question...my 3rd post

Now help me out with this one....are hazardous areas defined the same by NEC and the Canadian Electrical Code, Part 1?

 

[dtn6770]

Survey says...

Pretty much. The Zone classifications system muddies the waters some but even they appear to be common between NEC and CSA/CEC...North American practices.

Thank you Cooper Crouse-Hinds!!!!!!!!!!

Later

 

[HCBFlash]

You should research the actual wire you use. AWM is in fact "Appliance Wiring Material", and may be used within appliances, control panels etc. The particular AWM that you use MAY be MTW/AWM, or meet other engineering standards which may be applicable to obtaining UL listing for that particular cable. Perhaps the most important questions for you should be: temperature rating, chemical resistance (including oil and water), voltage rating. If a wiring (or associated electrical) component is UL listed and used as listed on a machine, it is thereby NEC compliant, in that regard.

NFPA 70 has no notes or tables for AWM as a category, including conduit fill, ampacity when buried directly in earth, etc, etc, etc. because it is not made or listed for those uses. As I don't have my copy of NFPA70 handy, I'll just have to venture to say that it has no similar references to MTW (machine tool wiring) either.

NEC compliance is only applicable to installation and assembly of wiring and electrical equipment in buildings and other occupancies specified by the AHJ (Authority Having Jurisdiction). It is a construction standard. A given piece of equipment CANNOT be "NEC" compliant, because "NEC" isn't a standard for the internal wiring of appliances or machinery. You should carefully read the entire first part of the code book, it explains much of this. You might be interested in looking at NFPA79, as it is intended to address your concerns.

I had an old inspector tell me a long time ago "It doesn't matter if there's scotch tape, razor blades and popsicle sticks inside there, as long as it's got that UL label". I think you get the point.

It is becoming increasingly common for AHJs to require UL (or other NRTL) listing of ANY machine/appliance. Building inspectors WILL NOT inspect such machinery, only the installation. Custom machinery manufacturers in the past rarely had to deal with this, but leaving it to whatever "electrical inspector" had to inspect the installation proved to be a poor risk. You probably realize that you can have 1 piece of equipment UL listed. If you make more than 1 (exact copy) of a given machine, listing expenses (per machine) fall proportionately.

I've been down this path, both as a machinery manufacturer, an installer, an inspector, and owners representative,,,, but not a lawyer.

BTW, MTW/AWM is by far my preffered wiring for machinery and control panels and systems. What everyone overlooks is the damage and partial insulation failure of the omnipresent ***N types of wiring, that is to say the splitting of the nylon jacket of the insulation. Does the cracking and splitting (and penetrations from scuffing) actually compromise the installation? Actually yes, typically, practically no. The AHJ would make that determination.

Please let us all know how this works out for you! and don't forget faq731-376

 

[dtn6770]

HCBFlash,

First off, thanks for the constructive response.

I'll do my best to check out NFPA79 but it may not be any more applicable to our "product" than the NEC. Some informaiton I have volunteered just to try to keep the discussion on track is that the compressor [systems] we package are industrial natural (or other) gas compressors. The skid we assemble contain the compressor, scrubbers, pulsations bottles, coolers, and the prime mover which is usually a natural gas fuel engine. These things are used in in natural gas transmission lines, gas gathering systems, and gas well injection/extraction. Think remote, unsupervised, and stand-alone installations. We pretty much buy all the parts and then assemble them on the skid which includes running conduit and pulling wire between the control (UL/CSA/UL/NEMA) panel (UL/CSA/UL/NEMA) and the sensors (thermocouples, switches, etc) and other end devices (valves).

We wire our electircal systems with MTW/THWN/THHN but when we get to what I term instrument & control wiring I find our guys pulling the AWM. I'd like to say the AWM has MTW listed on it as well but it doesn't. 106C, 600V, VT-1 (vert. flame) and some other junk is all it other than. The fact its a UL type wire is an improvement over our practices a few years back, from what I'm told.

Anyway, what I've got are folks that want to advertize our packages as "NEC compliant" relative to hazardous area classification (Cl. 1, Gr. D, Div. 2). I've got issues beyond the AWM wire. Only some of the engines we use have "CSA certification", others don't. And don't even get me started on our battery compartments.

The subject matter and all that comes with it is fairly intimidating but I'm picking up some speed. It's still safe to say I'm still in a blind leading the blind situation. Where I see this going is me offering my list-o-recommendations with the disclaimer that we should shell out for a electrical engineering consultant to evaluate one or two of our packages.

 

[HCBFlash]

Look also at NFPA70 300.1 (b).

Maybe dropping this thread and other links to someone with substantial input or control regarding specific wording of advertizing would help them.

I hate to come off as somehow rude or facetious, but I see a parrallel between claiming "NEC Compliant" and "Homeland Security compliant". Both have impact on conditions surrounding an installation of your equipment, but not the equipment itself.

 

[dtn6770]

I hear ya but you're preaching to the quire. I'm battling a long held perception.

It doesn't help matters when a couple of American Petroleum Institute (API) standars reference NFPA 70 in the context of hazardous area electrical systems.

None of us want packages that are unsafe for their intended application but I need to educate and convince some folks that we're trying to cram a round peg through a [smaller] square opening.

 

[stevenal]

http://nfpa-acs-01.gvpi.net:8080/rrserver/browser?title=/NFPASTD/7907

 

[dtn6770]

Nice link stevenal, I'll keep it around for reference.

At first glance, 1.1.2 ducks the issue(s) of hazardous areas installations,"...shall not include the additional requirements for machines intended for use in hazardous (classified) locations." But that's not to say I won't gain some useful information out of it.

If there's was to attach/insert/paste a picture to these posts I be thrilled to do so just to convey a better understand of our stuff. I'd just assume not list our web site address to avoing the promoting and selling issues.

 

[stevenal]

faq238-1161

 

[dtn6770]

Thanks stevenal! Here's an example of what all the fuss is about.

 

[HCBFlash]

I think a simple, straightforward fact has gotten lost by now, or not clearly enough spelled out; If an item with an electrical connection is UL (or other NRTL) listed, it [red]IS[/red] "NEC" compliant.