I want to run 20-30 feet of 12 gauge BX from the service panel up the wall and along a 10 foot high ceiling to reach my new jointer. Any reason in the NEC that this would not be allowed? Thanks
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Replies
Armored cable is for use inside the walls, you'll need to use conduit (pipe) for a surface install.
If this isn't a commercial space where you're expecting an inspection and having to comply with the NEC, I'd seriously consider using the BX as you've asked, but with the modification noted below.
Yes, the NEC does stipulate that BX is not for use on the surface of walls (as mj has noted above), largely because it can be damaged by something heavy banging into it causing the armored sheath to cut into the conductors and causing a short. That said, is this really likely in a residential environment (I'm assuming this is your home shop)? I've seen lots of older homes where BX was used on basement walls with no problems over many, many decades. Does that make it right? No, not from the NEC's view, but their charge is to promote safety in many POTENTIAL situations, however unlikely.
My suggestion in your situation would be to run the BX out of the top of the panel box (assuming that it's about 5'-6' above the floor) up to the 10' ceiling, then along the wall/ceiling corner until you get to the position of your jointer. Terminate the BX in a junction box at the wall/ceiling and bring conduit (with 12-gauge wire inside of it) down the wall to another junction box with a receptacle where you can plug in your jointer. Will this meet code? No. Is this safe enough? Yes. And, I would venture to guess that even a picky home inspector when you sell your house in the future won't really have a problem with it.
I've used this method many years in several professional shops that I've had and never had a problem. Basically, you're keeping the already fairly robust BX up out of harm's way, and then using conduit far enough down on the wall where a "collision" is far more likely to occur. Don't push the envelop and attempt to do this with Romex instead of BX -- that's just bad faith on your part and asking for trouble.
As a sidebar to when it comes time to eventually sell your house -- you'll hafta fill out a disclosure form stating if ANY additional work was done and by whom. If you install the BX yourself, then you should disclose it and it will prolly trigger a secondary inspection by a qualified electrician to satisfy the Buyers expectation of moving into a safe, code compliant home.
If the inspection reveals any code deficiencies, then you'll be responsible for the time delay and the cost of repair (or a price reduction without the repair). If you don't disclose the work and the new owner then discovers it, there's a two-year arbitration period where they can legally come back at you if they wish to pursue it.
As MJ mentions, it's often not worth installing electrical circuits yourself as it can trip up the sale for yourself or your heirs; or cause insurance claim headaches.
Options are to have a qualified electrician install it and save the invoice; install it yourself and consider removing it before putting the house on the market; or install it yourself and then have an electrical inspection done before going on the market and include the results in the disclosure.
All in all, you're at the mercy of Buyers and their inspectors if you eventually put the house on the market with a known code violation. What is often a non-issue to us woodshop owners can easily snowball into a huge deal to an overly nervous, first-time home buyer.
Will the BX work?... yes. But if you have a kitchen fire and an inspector finds the faulty cable install they could deny your claim. What are you possibly saving by fudging with the rules? The cost savings of the naked conductors vs the BX might even pay for the conduit. Even if you have the bx given to you and installed for free it's not worth it. ...Just my opinion as a homeowner, business owner, and landlord paying premiums on all three.
You may be authorized to do it with Teck cable, it looks and feel like BX but has an additional black coating .
FWIW. Conduit is code here even for residential so I have to run pipe for everything. Honestly it's pretty fast and easy to run a 20-30ft circuit to that new jointer. Give it some love and a proper place to plug in.
use liqui-tight flex conduit and THHN for the conductors.
BX is not a NEC recognized cable designation. Two types of metal armored cables are described in NEC-2023; Articles 320 Type AC and 330 Type MC (the difference is in the equipment grounding conductor) are permitted for exposed runs of cable. [320.15 and 330.15] Neither are permitted where subject to physical damage. [320.12(1) and 33.12(1)] Physical damage is not defined in Article 100, use your own judgment. I would submit wall and ceiling installation is safe. A tidy, workmanship-like installation with proper securing (12 inch and 4-1/2 foot) will be code compliant. Be sure to use termination devices listed for the product. Another consideration is how do you make the connection to your jointer? You can drop from the ceiling with a Kellems supported SOx cord or continue the AC/MC to a wall box receptacle. One other alternative. You may not wish to invest in a conduit bender, but HD an Lowes have 90 degree elbows and box connection offsets that would allow a first class EMT conduit installation. DKH, PE, Master Electrician