when using those push on mc/bx connectors with the red things in top of them do you still need antishorts? The mc pushes in and the connectors push into the box. Does any one know? some people say you still need anti shorts some say you dont. I would not think you do because you are not screwing nothing in that could short out the cut part of the MC
why not install them? they really don't take any time and they are free. the red insert does NOT protect the wires from the sharp edge of the sheathing, anti-shorts do. We use alot of those connectors... the only problems are when the guys don't use the anti-shorts.
[This message has been edited by ProCircuit (edited 04-28-2005).]
I did a little searching, bushings don't seem to be required for MC cable, but manufactures recommend it. And I agree with ProCircuit, the only time I have had a problem is when someone didn't use antishorts.
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.
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