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#215109 - 03/04/15 04:44 PM "Forbidden" Fittings?
renosteinke Offline
Cat Servant
Member

Registered: 01/22/05
Posts: 5299
Loc: Blue Collar Country
I figure it's time we had a thread to specifically address the use of fittings that accomplish, as best I can tell, things you're not allowed to do.

Now, it's possible that my understanding of the NEC is flawed. After all, all of the fittings I intend to bring up are UL listed- and UL, as a matter of policy, will NOT list something for which there is no code-compliant use.

Today's fitting is a new one, proudly introduced by Bridgeport Fittings. The fitting is intended to allow for the direct connection of MC to EMT. Look at it here: http://www.bptfittings.com/Home/ProductDetail?id=00781747944562

Now, the existence of this fitting brings up any number of tangents ... but I'd like to limit our discussion to one: namely, is there EVER a circumstance where you can use this fitting?

Some might say "sure- I can eliminate a box and just extend the MC wires back into the pipe, as far as I need to go, until I get to a box I really need."

The problem is- and feel free to correct me here- I think the NEC requires the wires to be marked with insulation type, etc. .... and NO ONE makes MC with marked wires.

What do you think?

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#215112 - 03/04/15 09:01 PM Re: "Forbidden" Fittings? [Re: renosteinke]
HotLine1 Offline

Member

Registered: 04/03/02
Posts: 6785
Loc: Brick, NJ USA
Common acceptable practice is the use of 'from-to' fittings to eliminate the need for a box. Over the many years I have been in the trade, I have seen, used, made up many a transition from cable to raceway, etc.

To get to the core of your topic, the markings on conductors IMHO in a situation would not raise a question.

I seem to remember seeing markings on some #12 or 10 MC. It was stranded for sure. I'll reach out for the EC who is on that job to check. I'm not disputing what you say Reno, I just feel it is something that just gets by without ????
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John

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#215122 - 03/05/15 10:02 AM Re: "Forbidden" Fittings? [Re: renosteinke]
gfretwell Offline

Member

Registered: 07/20/04
Posts: 9012
Loc: Estero,Fl,usa
I agree if you extended the conductors from MC cable through the EMT it is a technical violation. I also think that, presented with it, I would say it was better than another splice.
There should be marking on the MC cable that will suffice to tell me what the conductors are.

If this is FMC that they are using, no foul at all.
You should be pulling a marked discrete conductor anyway.

Since you don't have a firmly mounted box it will make strapping that EMT termination more important. (assuming you are transitioning to a whip)
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Greg Fretwell

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#215125 - 03/05/15 07:33 PM Re: "Forbidden" Fittings? [Re: renosteinke]
Tesla Offline
Member

Registered: 06/16/04
Posts: 1280
Loc: Sacramento, CA
The only thing missing is the markings...

But, since they erupt from a listed cable assembly -- MC -- and the EMT is even more protection than the aluminum 'tape' used by the MC...

I don't see a problem.

I've never heard "boo" about it from any inspector.

Now, obviously, if the MC was internally marked you'd be satisfied...

Of course, the wire used is THHN or better. These days THWN-2 is the norm.

It's required by the standards of the MC -- which is pitched as being able to handle generally wet conditions -- but not submerged conditions. (There's PVC coated MC for that.)
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Tesla

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#215126 - 03/05/15 09:25 PM Re: "Forbidden" Fittings? [Re: renosteinke]
electure Offline

Member

Registered: 12/24/00
Posts: 4225
Loc: Fullerton, CA USA

They said the "Use of Antishort bushings is required on AC/MC" too.

AC yes, MC no.

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#215127 - 03/05/15 09:53 PM Re: "Forbidden" Fittings? [Re: renosteinke]
gfretwell Offline

Member

Registered: 07/20/04
Posts: 9012
Loc: Estero,Fl,usa
There are still guys who want to see the bushing on MC but I agree it is usually not necessary.
OTOH if this connector actually says you need bushings in the instructions it is a 110.3(B).

I am still trying to think of where I would use this fitting.
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Greg Fretwell

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#215128 - 03/06/15 01:13 AM Re: "Forbidden" Fittings? [Re: renosteinke]
Tesla Offline
Member

Registered: 06/16/04
Posts: 1280
Loc: Sacramento, CA
Scott,

In Sacramento County, the AHJ DOES insist on red hats for MC.

BTW, the various listed fittings ALWAYS have a port so that - said red hat can be viewed.

&&&&

The reality that red hats are not needed everywhere has caused the trade to ship MC coils with either no anti-short bushings at all -- or just a teaser baggie -- with just enough red hats to be suggestive.

Inserting the red hats is such an insignificant labor burden that I pay the issue no heed.

Hereabouts, no-one ever uses AC -- except where mandated. (Hospitals, for the most part.)

&&&&&&&&&&&

For those wondering why AC instead of MC -- AC has a MUCH heavier 'tape' wrapped around it... and always did.

THAT'S the original, primary, reason why it was spec'd.

Then, as time went by, and low voltage electric devices became universal in hospitals, the redundancy of a belt and suspenders approach was deemed THE way to go.

Lest anyone forget, half of these gadgets are hooked indirectly into the blood stream! This makes the patient part of the equipotential ground plane.

So, hospital grade AC became endowed with additional grounding conductors.

Even with additional grounding conductors, MC tape is simply not deemed enough protection against physical abuse -- which you should read to mean: earthquakes and nuclear blasts.
_________________________
Tesla

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#215129 - 03/06/15 07:58 AM Re: "Forbidden" Fittings? [Re: Tesla]
electure Offline

Member

Registered: 12/24/00
Posts: 4225
Loc: Fullerton, CA USA
Originally Posted By: Tesla
Scott,

In Sacramento County, the AHJ DOES insist on red hats for MC.


http://www.southwire.com/commercial/nema-bulletin-90.htm

All of California is on basically the 2011 NEC, with CA Energy Code Amendments (2013 CEC)
They are only allowed to add their own local amendments to Building Codes under certain very limited conditions (seismic, climatic, etc)

I'd be willing to bet that the requirement isn't written down anywhere.

I personally use them even though they aren't required

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#215133 - 03/07/15 04:08 PM Re: "Forbidden" Fittings? [Re: renosteinke]
HotLine1 Offline

Member

Registered: 04/03/02
Posts: 6785
Loc: Brick, NJ USA
I see about 60-70% of MC installs with red heads. I guess IF the MC comes with the red heads, why not use them.

Back to Reno's fitting.......
_________________________
John

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#215135 - 03/08/15 10:09 AM Re: "Forbidden" Fittings? [Re: renosteinke]
renosteinke Offline
Cat Servant
Member

Registered: 01/22/05
Posts: 5299
Loc: Blue Collar Country
"Red heads" are, strictly speaking, outside the range of this thread. After all, there's no rule AGAINST using them.

By contrast, let's look at this clip made by Caddy:
http://www.erico.com/category.asp?category=R1106

This fitting is one of many that are designed specifically to attach conduit and boxes to suspended ceiling grids. I've seen installations that used these clips, so it's possible that they were allowed at some time.

Today, though, I can see no situation where the NEC allows anything to be supported by any suspended ceiling.

I don't buy the "for positioning only" disclaimer.

What about the lack of a UL listing? As best I can tell, supports are not required to be listed. Caddy lists its' "minerallac" style hanger, but not the one-hole straps. As best I can see, code allows you to hang pipe using rubber bands, shoe laces, and bubble-gum ... as long as you're not hanging it from the ceiling grid!

IS there any 'legal' use for these t-bar fittings?

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