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Joined: Oct 2000
Posts: 2,749
Member
We have been officially advised by NEMA that anti-short bushings are not required when Type MC cables are installed.
http://www.nema.org/DocUploads//8B117E35-EFF9-4B09-B6E4722E1E6DFEF3/BULL90.pdf

The picture here shows a Type AC 90 degree fitting, and the inspection hole shows where the anti-short bushing "redhead" was installed to comply with the Code.

Question: If this fitting was also permitted to be used to terminate Type MC cable would you require an anti-short "redhead" bushing? I think that it would enhance safety and should be installed.

[Linked Image]

I cannot imagine the true or real reason for the different rules!!

[Linked Image]


Joe Tedesco, NEC Consultant
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Joined: Nov 2002
Posts: 558
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Member
We still use them Joe. I can't think of a good reason not to.
The "red devil" as we call them,will just about eliminate any chance of damage from the rough edges of the armor.

Russell

Joined: Sep 2003
Posts: 650
W
Member
What is your preferred technique for cutting the armor. I use the rotary cutting saw (MC goes into a hand-held clamp, you squeeze, and rotate the handle, and the blade cuts the armor. Works _great_, except that the cut goes the long ways and leaves a very sharp point to the armor. I'd think that a 'redhead' is absolutely essential with this sort of cut. I much prefer the _results_ that I get when using a hacksaw...but the rotary cutting saw is ever so much faster.

-Jon

Joined: Aug 2003
Posts: 1,374
R
Moderator
Joe: When you ask "...would you require...", are you talknig from an inspection point of view or an installer's point of view?

As an inspector, I can not require it. See the definition of assualt and malicious prosecution.

As an installer, yes I would ask that my employees use them. Even it eliminates one service call, if was worth the money and time.


Ryan Jackson,
Salt Lake City
Joined: Sep 2003
Posts: 650
W
Member
There is a third perspective: the customer's.

I as a customer would require them, even if code does not.

Further question along these lines: when you are wearing your inspectors hat, do you verify that the installation is up to code, or do you also verify that the installation is up to whatever additional requirements the customer has specified? So, for example, if I as a customer requested anti-short bushings, and this was agreed to in the bid, is it the business of the inspector to report this if they are noted to be missing?

-Jon

Joined: Oct 2000
Posts: 2,749
Member
If this fitting was used as I asked, "I would insist on the "Redhead" and would dare the Judge and Jury to yank the cable while it was energized feeding this furnace.

Let's not have the new kids become brainwashed by the code, those with only a short time in the field with the tools.

Most "seasoned mechanics" would agree "put the red devil" in and be done with it!

This is another issue that will grow so old it will be able to vote!


PS: I used the hacksaw for the time when I worked in the field and the tool that cuts the armor is good too, but still leaves a sharp edge.


Joe Tedesco, NEC Consultant
Joined: Jan 2003
Posts: 4,391
I
Moderator
Joe you have me totally confused.

It was you that posted a statement from NEMA or UL that clearly stated they are not required.

The NEC does not require them.

So what are you saying with this post?

By the way I use them and expect the workers under me to. [Linked Image]

Bob


Bob Badger
Construction & Maintenance Electrician
Massachusetts
Joined: Oct 2000
Posts: 2,749
Member
Bob:

If the fitting I posted above was used it would expose the end of any Type AC or MC, cable and I would call for the bushing.

I am sure that the NEMA report is what everyone in the field understands and believes.

I would challenge each of the members of that committee to install a piece of AC and MC cable in the same box and expose the MC to a fault at its termination in a fitting, however you want, and the lack of the bushing will prove a point --- it will cause an arc, and a fire and create a hazard.

I call for a public meeting in a place where we can perform this test and see the results, or maybe someone would agree to do a video of the same test?

PS: I am glad you do approve of the use of the busings anyway, you are a "seasoned mechanic"!


Joe Tedesco, NEC Consultant
Joined: Oct 2000
Posts: 5,392
S
Member
Joe,
'yanking' live wiring through any number of raceways would probably result in fireworks despite the best of installs...

of course, should NEMA choose to pursue this manner of testing, i'm sure there will be an accomodating NRTL

~S~

Joined: Jan 2003
Posts: 4,391
I
Moderator
Joe how can you say "I would call for the bushing"

You have no code article to cite.

Now in reality if I was presented with this situation it would be easer to put the bushing in than fight the inspector on this.

But an inspector is to enforce the code and not his or her own preferences right? [Linked Image]

Bob


Bob Badger
Construction & Maintenance Electrician
Massachusetts
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