Could a short piece of EMT be used as a sleeve to protect MC cable. A two foot piece protects the MC cable which then is terminated to a hot water heater. I was going to tell the Electrician to Re-do it, but I wanted to throw it out there for a Code Interpretation. Thanks
If just a sleeve, then the way 300.15[C] is worded, itís okay to do this with any cable type as long as there are fittings on the ends of the EMT to protect the cable from abrasion. Iíve used those plastic push-on bushings made by Arlington for that purpose before.
But, at least IMO, if actually changing wiring methods I feel that at least a changeover connector on the end of the EMT should be used as allowed in 300.15[F]. This may be up for debate though.
I agree. They should have ran the EMT to a junction box and then directly to the control box. The EMT is floating and I don't like it. Chances are the EMT will not get energized but ya can't tell the judge that. Good Weekend
I can imagine circumstances where you might want to sleeve a piece of MC; perhaps there's a particular section that might be subject to damage, or that you want to 'keep out of the way' and lack support points. Finally, theres the issue of penetrations, especially where you want to allow for future replacement of the cable.
Indeed, you would have to use a sleve if you had multiple cables to address.
I'm not worried at all about the sleeve becoming energized. Here's why:
First, we are not required 'structural metal that is unlikely to become energized.'
Second, there is the jacket of the MC, which is bonded. If the EMT is going to become energized, don't you think that the electricity is most likely to originate in that MC?
If you're a purist, you could assemble a fitting to make a direct MC -> EMT transition. If you're worried about abrasion, a connector or coupling on the ends of the EMT can address that concern.
What about dissimaliar metals? I would just use and EMT connector to a threaded half coupling to a M/C connector remove the sheath and install. I have done this in commercial building were M/C is run in the ceiling then surfaced mounted down the wall.