Is there a code provision that prevents the use of a 3R pullbox to enclose a 480V. 3 pole contactor? I need to order this ASAP and can't find anything on it.

Is this being used also as a pull box?? Or just a 3 R junction box being used to enclose the Contactor?? If its the latter then I;d say its done all the time.

I've done it as a mater of routine .... but some folks have run into issues with their AHJ - who wants a hinged door.

IMO, there's no code issue, and trying to apply 'listing and labeling' is quite a stretch. Heck, I've even had folks object to cutting holes in the boxes, rather than using the factory KO's. Go figure.

As Reno said, it's routine. Contactors/relays in NEMA1 are also routine (in compliant locations) as using any other enclosure.

Could the issue be the 'opinion' that the complete assembly is not 'listed/labeled'? Or could there be an issue with conductor volume, or bend radius?

It's just that I had an inspector in the LA area tell me I couldn't enclose a contactor in a pull box because the box wasn't listed for that use. It was a long time ago and I never did find the code section. I guess it doesn't exist.
Thanks for the help!

OK, try this scenario...

Enclosure has a UL label/listing as a pull or junction box, based on the UL White Book? If that is/was the case then by the 'book' he's technically correct.

Did the enclosure you used have a backplate? Mounting studs?

Did you have a Sq D (or other mfg) that has a 'factory' enclosure in their catalog?

From your last post, sounds like that AHJ may have had a UL White Book with him

It was just a regular pull box with the contactor mounted using tech screws. I see what you're getting at though. If there is a specific box made for that contactor then it seems
reasonable that the inspector would want the approved box to be used. In this case I'm looking at a 5 day lead time if I want it in a specialized contactor box. Uhggg!!

We:

"mounted using tech screws" ??

That could have been a factor.

I have one of those Greenlee tap kits now. Boy those are sure nice with the all in one drill and tap.

What is the code issue with tek screws?

Drilled and tapped is nicer and more professional but you make less money. From all the jobs I've seen, 99.532% of all contractors use Tech screws to mount things in their pull boxes. Come to think of it, I guess it could possibly fall under grounding 250.8. A sheet metal screw is not allowed for grounding the frame of the contactor to the box.

I guess I'd like to kick in on this one. I think "tek" or "tech" screws are some sort of sheet metal screws either self taping or self threading and you may or may not have to drill a hole first. Bad way of mounting relays or any other component that has moving or vibrating features associated with it. If we look in Article 250.8 for grounding we need two full threads for acceptable grounding connections. Any J-box or "Hoffman" type box designed for mounting equipment contains a back plate feature and a back plate that is about 1/8th inch thick so equipment can be mounted on it with machine thread type screws. The back plate is raised so that the screw does not bottom out and also so it can be loosened, tightened or removed and replaced when the equipment is installed. If you are using any other method your standard is less than mine and probably most inspectors. Maybe a quick JIC standards class would help. As for pulling wires through the box in addition to the relay being properly mounted, I see no problem with that since it is permitted elsewhere in the code. See: 312.8 or 404.3(B)

I have never written 110.12 in 20+ years as an inspector but using "tek" screws to mount a relay would certainly be considered here.

Don't read more into 250.8 than is there. It says



There is nothing there about mounting equipment, even equipment that has to be grounded like the case of a washing machine. That is put together with sheet metal screws.

I also disagree that a contactor is going to cause that much vibration. 4 Tek screws in a 16 gauge box will not be coming loose. I wouldn't use them for a motor but that is not what we are talking about.

You can always argue it is not good workmanship and looks sloppy but I am not sure that rises to the level of a violation.

The OP doesn't give us enough information. If this relay is large enough it certainly will have a vibration if and when it its energized. Don't know if this is something that needs grounding either. This is pig work when they start installing equipment this way and I'm just the guy to use 110.12 and let them prove me wrong. I guess I better apologize for my standards but the NFPA 70 and NFPA 72 and the JIC Standards are minimum in my life.

Gentlemen:

IMHO, I did not quote any article, 110.12 (neat/workmanlike) is subjective and NJ does not recognize it. 110.13 may be a 'stretch', based on the interpertation.

I mentioned a 'list' of possibilities, and without info from Wewire, we are kind of shooting from the hip.

Professional craftsmanship, neat and workmanlike manner, etc., are considered 'gray areas'.

Another possibility? the tek screws projecting thru the back of the box, hindering mounting? Or the box being deformed? Or, the teks being pushed out by the box mounting? Or the teks protruding thru the back of the box which may cause injury to someone?

I'm sure if we all think hard enough, there are more possibilities! My judgement of the 'quality' of any install unfortunatley cannot be cited, although there may be something(s) that can be cited.

How do they mount boxes on steel studs?

Sorry bout that. I thought I made it clear that the only thing the inspector said was that is was not listed for that use, meaning that the box was not officially a contactor enclosure. I was jogging my memory since this was in late 90's when he called me on it. It was actually a 120V. relay that he was concerned about. I found a contactor and an approved box for this job I'm working on. It is interesting to see what issues come up here. Seems like most customers are looking for the
lowest price on jobs these days so doing things the absolute most bestest top quality time consuming way isn't
always a customer's priority. However, it does need to be a safe installation. That leaves lots of room for argument though. I guess if screwing a contactor in a box with tech screws is "pig work" then I plead guilty. :0

I have been watching this discussion, and being an inspector myself, I tend to agree with George on this one. My first thought is that I would want to see some documentation that by enclosing the relay in the enclosure it would not be in violation of 110.3(B). There may be heat issues here and ventilation and size could be a factor. In regards to using tek screws, they are not approved as an equipment grounding means. The relay base would have to be grounded or bonded per 250.8 and tek screws do not qualify. The fact that washing machines use sheet metal screws does not give any validity to this discussion. Washing machines are listed by a testing laboratory where as the relay in an enclosure is not listed. If you will look at 110.2 it state that equipment required or permitted by this Code shall be acceptable only if approved. Approval lies with the AHJ and the requirements are spelled out in 110.3(A). In lieu of doing their own testing most AHJ’s require listing and labeling. I often put the burden of proof on the contractor and that’s the way I would handle this one. If he could show me documentation where the relay and box are compatible, and he uses a 250.8 method of grounding or bonding, I would then accept it, but otherwise I would not.

Regards,

Tony

Tony, where does it say you can't use tek screws to mount hardware. 250.8 says "conductors and bonding jumpers".

Teks screws - good heavens, if you're going to try to paerse things, get the name right! "Teks" is a brand name / trademark of fastener made by ITW. That's TekS, not TeK.

I'll make the same point I made in the 'sheet metal screws for bonding' dispute: Using the correct fastener for the application that it was designed for is perfectly proper. It's only when you use the wrong fastener that you have problems. For attaching things to sheet metal, a Teks screw is perfectly proper - that's why the last code cycle modified the 'no sheet metal screws' rule to where I believe that the rule no longer applies to Teks screws - but that's another discussion.

There has certainly never been a rule against using Teks screws for uses besides attaching a bonding wire. Don't try to 'infer' this because think the box should be bonded to the metal wall, etc ... because these are the very screws that hols metal stud walls (light steel framing) together.

Now, if someone is using Teks screws to attach things to drywall, masonry, or wood, there's an issue.

As for the enclosure issue .... IMO all that matters is your fill factor, and that the enclosure do it's job.

We've become spoiled by our ability ot make custom products. One need not go far back in time - indeed, there are likely still some example around - where the 'factory made' items used the same enclosures as you might get from a supplier. Only later did the manufacturers start gettig fancy, with custom features like hinged doors, mounting flanges, and custom sizes.

Yet, this topic is the equivalent of disqualifying the winner of the Boston Marathon because it was found he wore "Cross trainng" shoes, rather than "running" shoes.

Holy cow Reno!! If you're gonna write a reply at least spell the words right!It's It's "getting" not "gettig", it's "to"
not "ot" (OT is when you work late for more money)and
trinng shoes aren't available anywhere. Aside from that, your
reply was A+ and you had some great points. Especially the
steel stud part even though you spelled holes wrong. Keep up the good work sir!!

Well, I sure had that coming ....

I also really miss the edit button - oh well. Point made, and reply accepted with grace.

I believe that 250.8 still applies here because the base of the relay must be grounded or bonded to the enclosure. Teks screw( so sorry for the improper moniker ) are a form of sheet metal screw and to my knowledge are not thread-forming machine screws that engage not less than two threads in the enclosure as required by the code. I believe that they may work fine for holding studs together but they are not approved for grounding or bonding. I have written many violations where someone has used a “Teks” screw to secure a lug to a panel or enclosure and will continue to do so until someone shows me where they are rated for that purpose.

Regards,

Tony

The base of that contactor is not a conductor nor a jumper.
I am forced to read the words of the code and enforce them. I can't make things up.
I also wonder how much evidence there is that these provide a less than satisfactory mounting strength.
I asked before, how do you attach boxes to metal studs?
I see them using self drilling thread forming screws.
There is certainly a lot more direct force applied to a receptacle box with plugging and unplugging than you have with a contactor making and breaking. In Florida that is also how you bond the steel studs.

To drag this back on topic I will agree with those who say there may be a difference between a pull box and a cabinet.
I am just not sure what it is.
If you were concerned you would be looking for proof that the enclosure was evaluated to UL50 standards.
The same standard applies to Junction and Pull boxes (BGUZ) and Cabinets and Cutout boxes (CYTV) so this seems to be a distinction without a difference.
Personally I would be a lot more concerned with the weather rating, wire bending space and the usual stuff. I might think the self drilling thread forming screws were an expedient but I would be hard pressed to see the violation.
I don't like tywraps either but I hold my nose and let them go.

Greg:
So we don't get off on the wrong foot here..

Teks (Tek) screws are what is used for metal stud assembly, and what is commonly used to mount boxes to metal studs.

I think if my within comments were read, I eluded that I would not write a 'red' for what the OP said, all I was getting into is reasoning why it was an issue for a 'red'.

I am a bit confused .... I've never seen any sort of relay / contactor / starter / overload / whatever where the base had to be grounded. That is, the body of the device was grounded by its' mounting screws.

All I can remember seeing were components made of some non-conducrive material. The only terminals provided were for the load-carrying conductors and control wires - not even a place for attaching a bonding jumper.

Now, if you're saying that the enclosure must be bonded, pull boxes have their own points that are specifically prepared for accepting a green screw. This location is distinct from the mounting holes.



Maybe we're thinking different thinngs when we say 'contactor.'

I don't think there is a requirement for the base to be grounded, it just happens incidentally in a metal box.

That's my point, Greg ... I don't care how you fasten plastic, or bakelite, or whatever they make contactor of, to a metal bok .... what are you grounding? The only conductive parts that are exposed are 'live,' and you surely wouldn't want them bonded.