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Joined: Jan 2003
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Thanks "Big Guy" I do not see that 110.7 requires Red heads, 110.7 tells us we will not intentional leave any short circuits, at least that is how I read it. Not using a redhead does not guarantee a short circuit, it does make me wonder if there will be one. Tradition is why the makers send redheads. ![[Linked Image]](https://www.electrical-contractor.net/ubb/smile.gif) Here is a NEMA statement on Anti-Short bushings. You can download it from NEMA here. NEMA Bulliten 90 Use of Anti-Short Bushings (pdf) NEMA ENGINEERING DEPARTMENT BULLETIN No. 90
August 14, 2002
Use of Anti-Short Bushings for Terminating Type MC Cable
There has been much confusion within the Installation and Inspection communities regarding the use of anti-short bushings for terminating Type MC cable. The confusion stems from the fact that some MC cable manufacturers include anti-short bushings with their cable. The inclusion of anti-short bushings with coils or reels of MC cable is based on historical practice relating to the requirements of 320.40 of the NEC, which mandates the use of anti-short bushing or its equivalent protection for Type AC Cable.
Fittings used with Type MC Cable are required to be listed per 330.40 of the NEC. NEMA supports the use of listed fittings for MC Cable. The design of these fittings may or may not include an insulated throat however, they are required to be provided with a smooth, rounded end stop so that the metal sheath of the cable will not pass through and the wires will not be damaged in passing over the end stop. Whether or not an insulated throat is part of the listed product, these listed MC fittings do not require an additional anti-short bushing. Anti-short bushings that may be supplied by MC Cable manufacturers are for optional use by the installer, however they are not required.
ROP #7-116 from the May 2001 Report on Proposals (ROP) for the 2002 NEC was a proposal seeking to require anti-short bushings on all MC Cable termination installations.
The following is an excerpt from the Panel statement rejecting the proposal:
Anti-short bushings are not required for Type MC cable in accordance with the listing for the product. The termination fittings approved for use with Type MC cables are designed such that the wires will not come in contact with the cut edge of the armor; the throat of the fitting is small enough to prevent contact with the armor. Type MC termination fittings perform the same function for Type MC cable as Type AC terminations plus the anti-short bushing do for Type AC cable.
NEMA supports the uniform adoption and enforcement of the NEC and recommends that local Authorities Having Jurisdiction follow the requirements of NEC Section 330.40, Boxes and Fittings for MC Cable. Section 330.40 requires that the fitting be listed, but does not mandate the use of an anti-short bushing.
Distribution List:
Standards and Conformity Assessment Policy Committee
Codes and Standards Committee
NEMA Executive Staff
Bob Badger
Construction & Maintenance Electrician
Massachusetts
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Joined: Feb 2004
Posts: 62
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Iwire, Thanks for the NEMA statement. I have been looking fr something in writing that states that anti-shorts aren't required. BTW, I still use them.
Good looking job. One question. Are you doing a lot of strictly MC commercial jobs in your area? We are still using mostly EMT here.
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Joined: Oct 2000
Posts: 2,723 Likes: 1
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Darn good job, Bob!!!
As to the clean jobsite, if the place becomes messy and no one from the GC's staff can / will sweep / clean up, I have no problem grabbing brooms / shovels / rolling dumpbins / 1-2 Apprentices for additional help, and cleaning the place up.
Can't stand a messy workplace!
Scott35
Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!
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110.7 Insulation Integrity.
Completed wiring installations shall be free from short circuits and from grounds other than as required or permitted in Article 250.
ok that is what it says
do you know how many time's i have had to move a 2x4 trofer and BOOM
IF you don't use them it will happen
what do i know I just do this for a living
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Joined: Aug 2001
Posts: 466 Likes: 1
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Bob,
I noticed that you are using the deep boxes for the LV wiring also. When I took a LV course the instructor said to use rings only, so as to leave enough room for all the cables and to maintain the bend radius. He was talking about at least a foot on all the LV cables. Your thoughts?
PS, nice looking job.
Jim
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Jim, normally I would use rings. This one as a matter of fact. ![[Linked Image from erico.com]](http://www.erico.com/public/images/products/FF-Datacomm/NorthAmerica/13656667.jpg) This one acepts 3/4" EMT. Job specs called for boxes, the engineer knows best. ![[Linked Image]](https://www.electrical-contractor.net/ubb/wink.gif) Of course at the office cubicle Data drop locations the plans called for a 2" EMT into a 2 gang box. ![[Linked Image]](https://www.electrical-contractor.net/ubb/biggrin.gif) The Data contractor is doing fine with these and they are certifing the work. Bob
Bob Badger
Construction & Maintenance Electrician
Massachusetts
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Looks good Bob. I too like a clean jobsite. Makes life easier for everyone. Unfortunately it seems to be the exception rather than the rule. Big Guy why the hostility?
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Joined: Dec 2000
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Bigguy, Do you move the troffer while it's turned on? We do this for a living as well, and I think the general consensus has been that although not required, we still use the bushings. I contacted a couple of manufacturers about this about 2 years ago, and found out that they weren't required. I don't think I've put in 1 piece of cable without them since, tho.
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Joined: Jan 2003
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One question. Are you doing a lot of strictly MC commercial jobs in your area? We are still using mostly EMT here. Almost all jobs here go out to bid with EMT specified. Then the customer gets 'sticker shock' and value engineering starts. Cables are king here in MA, MC, NM, AC etc.
Bob Badger
Construction & Maintenance Electrician
Massachusetts
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On jobs with literally miles of MC, what technique do you use for cutting the stuff?
For smaller jobs I just use the rotary cutters, but these leave an ugly sharp point that screams 'fix me'. Cutting this point off with kleins seems to make things worse. The only solution that I find acceptable is to use the red heads.
Knowing that the red heads are not required, I wonder if for UL testing they have some sort of uber-clean cut on the end of the armor...I could imagine a tool which makes a nice, clean, de-burred edge giving vastly different results in terms of safety versus a standard saw cut.....
-Jon
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