Improper Use of Fittings

[barbeer]

I am pretty sure that I did not see any anti-short bushings shown in that fancy NEMA thingy!? Anybody think of that?

 

[roger]

I am pretty sure that I did not see any anti-short bushings shown in that fancy NEMA thingy!? Anybody think of that?

There's no requirement for "anti-short bushings" on FMC installations.

Roger

 

[barbeer]

I was if fact thinking about the AC and MC cable aspect of the presentation, not the FMC since the presentation addressed all three!

 

[hillbilly]

Hillbilly,

(s)Lowes is not exactly the shining pillar of electrical knowledge in the industry. I think if you had all the code gurus standing pointing at it, it would be considered a violation. If they were out on a job, they'd do it in a heartbeat, and file it in the"it wasn't pretty, but had no options" closet that like everyone in this industry, has "some junk in the trunk".

I have no problem with it if it is made tight and secure, and has an EGC (wire) sized per 250-122.

Anyone have a NEIS book that covers this?

Is there anyone sitting on a CMP that wants to tackle it?

I don't believe that Lowes used their own "experts" to wire their own building.
This job was done by a large local contractor in a county that is notorious for tough inspections.
It was 1 1/2" EMT and I assume the sparky had pulled a EGC in the circuit.
I saw no problem with the installation and would probably do it the same way.
steve

 

[iwire]

I was if fact thinking about the AC and MC cable aspect of the presentation, not the FMC since the presentation addressed all three!

The only wiring method that requires the use of Anti shorts is AC.

There is no NEC or UL requirement for anti shorts with MC.

That said I can not make an MC termination without a red head, it just makes sense to me.

 

[barbeer]

Bob-

I agree about the anti shorts and MC cable! That said, UL says that the connector assembly rating varies by specific connector type? I do not have a UL manual 1569 to read up on it either. NEMA(I know you are not a big fan from previously in the post) also says the NEC does not require anti shorts. I guess the question is- Do certain connectors require the bushings to achieve rating and certain ones they are not required. I do turn down a job where they are not used.

 

[roger]

Barbeer, if you are turning down an MC istallation for no anti-short bushings you are in error regardless of the fitting used.

Read 320.40 and then 330.40 for the specifics of where they are required, the only place a fitting type verses Anti-short bushing or not would come into play would be for AC installations.

Roger

 

[iwire]

barbeer

NEMA(I know you are not a big fan from previously in the post) also says the NEC does not require anti shorts.

Sorry if it came across that way, my only point was NEMA could not 'make a rule' that has any real force. I also wanted to point out whats NEMAs real mission is.

I don't consider NEMA 'evil'.

Do certain connectors require the bushings to achieve rating and certain ones they are not required. I do turn down a job where they are not used.

I can not see how you could turn the job down as long as they are using listed MC connectors.

What code violation would you cite?

NEMA has issued a bulletin (not a rule ) that clarifies the fact the neither the NEC , UL or the manufacturers require anti shorts with MC cable. They also point out that the fact MC ships with Anti shorts is more of a courtesy than anything else.

They go on to point out that any listed MC connector is designed to protect the conductors from the armor. (I personally disagree that all MC connectors accomplish this)

There is a new MC on the market (MCAP from Southwire) that one of their selling points is that no anti shorts are required.

The company I work for requires we use them and I would use them anyway.

I have 'cheated' on this with large MC 2/0-4, 4/0-4 etc but I also take a lot more care in making these terminations and will leave the Mylar with some added tape on the conductors where they pass through the connector.'

Bob

 

[davet]

Metal Conduits:How many amps?

Metal Conduits:How many amps?

Q:If running metal conduits containing your wiring system with no seperate ground wire(using cinduits as ground.Ex:3 phase circuit,no neut.) and a short results in conduit,How many amps can the conduit run handle? Is there a chart showing the different sizes of metal conduit that can handle the current fault? Ex:1 stick of this size and type can handle x number of amps.
Would the run of conduits be cummmalitive as far as handling current fault?

 

[iwire]

Q:If running metal conduits containing your wiring system with no seperate ground wire(using cinduits as ground.Ex:3 phase circuit,no neut.) and a short results in conduit,How many amps can the conduit run handle?

The conduit will handle more current than the size EGC that is usually pulled inside it.

Picture an 1.25" EMT containing a 100 amp feeder of four 3 AWG CU and a 8 AWG CU EGC. The 1.25" EMT can handle more current than the 8 AWG inside it.

If I recall correctly once you get past about 300' of EMT you need to start worrying about the fault path.

Don has a link to a calculator for figuring this out precisely.

 

[don_resqcapt19]

You can get the software Bob is talking about from the Steel Tube Institute.
Don

 

[renosteinke]

Improper use of fittings

Improper use of fittings

The law has a priciple known as "de minimus". This doctrine says, in effect, 'don't sweat the small stuff.'

Joe chose a poor example, simply because it shows something that is - whatever else you can call it - neat, workmanlike, and well supported.

This pic I took is of a very similar install that is none of those things. Indeed, while I have no problem with Joe's example, this one I felt obligated to replace:

At some point, judgement HAS to enter the equation. Not every detail can be called out by the book, and it does not inspire respect of the law when "the law is an ass."

A collection of fittings can be clever ... or an abomination. One needs to 'engage the brain' , rather than relying upon boilerplate citations.

 

[Jacob S]

I was standing in line at (s)Lowes the other day. While waiting, I look up and what do I see? A transformer installation using exactly the same parts as Joe's picture.
steve

Steve's comment along with this entire thread has reminded me of a huge pet peeve of mine at every home depot I have ever been in. In my area, the stores use large dome camera suspended using 3/4 inch emt and set screw connectors. The attachment to the structure is either a blank on a 1900 box punched for a emt connector or a swivel mount plate that you would use for high bays. I get very picky when suspending equipment over peoples heads and this just irks me. I have actually seen one snapped off at the ceiling in Charlotte hanging by only the coax conductor. I am more concerned about this improper use of fittings than the whole ridgid coupling debate.
Jacob

 

[mdshunk]

Steve's comment along with this entire thread has reminded me of a huge pet peeve of mine at every home depot I have ever been in. In my area, the stores use large dome camera suspended using 3/4 inch emt and set screw connectors. The attachment to the structure is either a blank on a 1900 box punched for a emt connector or a swivel mount plate that you would use for high bays. I get very picky when suspending equipment over peoples heads and this just irks me. I have actually seen one snapped off at the ceiling in Charlotte hanging by only the coax conductor. I am more concerned about this improper use of fittings than the whole ridgid coupling debate.
Jacob

I see a similar arrangement for suspended exit signs from time to time. I do the same installs, but with RMC or IMC down rods and jack chain for a safety chain on the exit signs. You can split a set screw fitting sometimes by cranking the set screw too hard sometimes. I certainly wouldn't want to rely on its mechanical strength to support something.

 

[Jacob S]

I see a similar arrangement for suspended exit signs from time to time. I do the same installs, but with RMC or IMC down rods and jack chain for a safety chain on the exit signs. You can split a set screw fitting sometimes by cranking the set screw too hard sometimes. I certainly wouldn't want to rely on its mechanical strength to support something.

This is especially true when they used die cast fittings. The camera I saw snapped off was where the threads joined the body of the connector.
Jacob

 

[Mike03a3]

Uh, Joe, I agree with what they've posted and I'm not been approached or brainwashed by the moderators.
<big snip>

Apparently you drank the moderators kool-aid, and then were assimilated.
:grin:

 

[George Stolz]

LOL, I was wondering when that was going to come up.

Don't worry, the comet will be here any day, and then you'll see.

 

[RayS]

Could be called: Mix and Match. Fittings shall be permitted to be used anyway you want as long as they work.

Now that is a model of clarity and practicality that should be copied.

We assume, of course, that by "working" the result will be safe.

I've gotta add that the install cited looks solid to me- What is the problem? I understand the issue may be that the fittings may not be used in complete accordance with sombody's instructions (I read the link, but did not find where NEMA said it was outlawed), but dang, I think common sense has to trump verbosity on this one.

 

[neonjoe]

Over an hour of my valuable time has been spent reading and studying this thread. An hour well spent, I might add.

I, being one of "the vast membership here" who "will sit back and take notice of this common occurrence", used to make my EMT, FMC connections in this manner after seeking the advice of the electrician on the job where the situation first occured, many years ago. Though I was never red tagged, when I first became aware of the adapters made for this, I started using them and will continue to do so.

In my trade, I never use anything but 1/2" conduit containing only one conductor, the GTO wire used for neon. This fitting provides a convenient and structurally sound method for my purpose.

But, after reading all the posts, I have to agree with those who prefer to use the 3 fittings to accomplish the same thing.

 

[joe tedesco]

2003-1-Field-Rep-Training-FittingsInstall

2003-1-Field-Rep-Training-FittingsInstall

I disagree, nothing has been presented from the NEC, NEMA or UL that prohibits this practice.


It is simply a practice that Joe does not like.

Go to www.nema.org and see the ppt file identified below on how fittings are supposed to be installed.

The use of fittings used improperly is the issue!!

Search for this 7 MB file or maybe someone already has the exact link, 2003-1-Field-Rep-Training-FittingsInstall