Looking around my mothers garage, planning to clean it out and notice a couple things. Thinking about updating the garage.
Is it okay to use regular armored cable in the garage, you know the rope like corrugated steel cable/armor clad type? I noticed that there were a lot of cardboard boxes stored in my moms garage up against/touching these cables… is that dangerous in any way? Should I move them away? What happens if a wire inside the metal cable breaks? Does it trip a standard breaker? and Also is the breaker for the garage fed into the house? I believe the wiring was last fully replaced/done in 1988 if that helps.
Also, what is the real name of that flexible armored steel cabling?
Sorry for so many electrical questions on here, just trying to learn more
I pulled your questions out to answer individually: Is it okay to use regular armored cable in the garage, you know the rope like corrugated steel cable/armor clad type? Yes, properly installed this is a better option than the NM plastic stuff. Different code requirements require differing wire methods and parts.
** I noticed that there were a lot of cardboard boxes stored in my moms garage up against/touching these cables… is that dangerous in any way? Should I move them away?** If the boxes are not stretching or putting pressure on the wires, there is nothing inherently dangerous with it. As long as the armor sheath is a continuous unrusted uncut path, it is not an immediate issue.
What happens if a wire inside the metal cable breaks? Does it trip a standard breaker? Properly installed, the metal sheath is the ground wire for the system. If the cable connections are solid at the junction boxes and the breaker panel, a broken wire internal to the cable should arc out to the shield and blow the breaker. If it doesn’t arc out, there is no more danger than any other system with an energized broken wire inside. If the connections are not solid, the metal sheath may become energized (live / hot) instead of blowing the breaker, the same as any other ungrounded system. and Also is the breaker for the garage fed into the house? If there is not a breaker or fuse box in the garage then the breaker must be in the house. I assume the garage is detached based on this question. There should be an overhead cable or someplace where the wire goes underground. Is there more than one circuit in the garage? I believe the wiring was last fully replaced/done in 1988 if that helps.
80’s installation by a competent licensed electrician following the codes of that day should still be OK except you maybe want to read up on the usage of GFCI and AFI breakers in garages requirements. Also, are the receptacles grounded? Waterproof covers where required? Garage door opener on a dedicated outlet? Also, what is the real name of that flexible armored steel cabling? Armored cable is also referred to as BX. MC is another term that means slightly different things.
IANAE, but as I understand it, there are two types of armored cable, sometimes generically but incorrectly called BX cable. AC cable as you say uses the exterior metal cladding as ground. MC cable has an internal ground wire like Romex; the exterior cladding is not used as ground. In the event of a ground fault, the exterior cladding of AC cable may be come energized, but that’s not possible (or not very likely) with MC cable. It wouldn’t be a good idea for something conductive to be in contact with AC cable in the event of a ground fault.
This is all based on my probably imperfect understanding; I hope an electrician can correct any misstatements I’ve made.
I had a 40’ X 40’ barn built in 2012. I didn’t want to use standard “Romex” due to concerns of mice eating through the insulation. I wanted armored cabling. I learned there are two types:
armor clad (AC). This has a steel sheath with two conductors inside. The ground is provided by the sheath. It is a very old design; you often see it in old houses. I would not use AC cabling.
metal clad (MC). This has an aluminum sheath with three conductors inside. I used this. Am very happy with it.
For the MC cabling, even though the sheath is not used for the ground return, the sheath still needs to be grounded. (This is automatically achieved if you use metal boxes & clamps, and ground the boxes.) If a wire breaks inside the sheath and makes contact with the sheath, the circuit breaker will trip.
You can buy a special tool that cuts through the sheath without damaging the wires inside. I highly recommend using this tool.
Use box clamps that are approved for MC cabling. These “clamp around” the sheath - they do not use a single, radial screw. And always use the red, plastic thingy with the clamps to minimize chafing.
For standard 120 VAC branch circuits, I always run 12 AWG cabling, not 14 AWG cabling. I do this even if the receptacles are 15 A. The only time I use 14 AWG cabling is for lighting circuits that don’t draw much current.
I really wouldn’t advise putting the lighting [del] and garage door opener [/del] on a GFCI. Okay code changed when I wasn’t looking. Used to be an exemption for door openers and dedicated outlets. That was removed a few codebooks back. I’d still like my lights to stay on when the outlets trip.
Reading this has given me a lot of tips, keep them coming. I love learning this stuff. Definitely going to separate them, in case some hypothetical happens and the garage door trips a breaker, I don’t want to be in the dark.
The reason why I want to use the Armored Cable is because there are a lot of rats in this area, no in the garage, but I see them in the alley’s all the time. Have to use armored cable in Chicago anyway I just found out so I’m going with that. I doubt a Chicago sewer rat could chew through one, well I don’t doubt it but I rather it be difficult. The only reason I asked is even though I’ve heard many places that it is required in Chicago to use armored, it’s annoying to pull. If I drill holes and run it perpendicular through studs, could a broken wire inside the armor heat up the casing and set a stud on fire? If I’m going to do something I want to do it right and the most safe way possible. I like places that I live and my family living to be like fortresses. Thanks again! Never disappointed on here.
I’m not sure why you keep mentioning broken wires. Under what conditions would you expect a wire inside an MC cable to break? I can’t imagine that happening. Unless maybe someone accidentally drilled into one.
It will never be cheaper to replace that breaker if you DIY. The breakers are $30-$50, while GFCI outlets (from reputable brands) run as low as $7. You do not want to even open the panel DIY if you can avoid it, as the main lugs will still be live at a minimum. While you can change an outlet completely safely DIY so long as you make 100% sure the breaker is off.
Downside is that if the wire goes to light fixtures or something else first, the GFCI outlet won’t catch that fault. Nor will it catch faults in the wire leading to the outlet. So if you’re doing a new house, you might as well just have all GFCI breakers for the circuits where this is required or helpful. (electric hot water heaters aren’t required to have them by code, for instance, but this is helpful and sometimes required by the manufacturer’s installation instructions)
GFCI lighting protection is debatable. If the device trips, you end up in the dark and might get hurt, but it can save your life if you are sloppy replacing a bulb. What LSLguy is talking about (separate wiring for lighting) would be nice, but we have to live with the homes that we have or can reasonably purchase, and generally the same circuit gets used for both to save wire and electrician labor.
So it sounds like this issue has always been there. Quickest fix for that is a solar powered motion activated security light. Trip the power and before you get to the third word in WTF at least some lights are back on. Something like this. Throw the solar cell on the roof / wall and drill a 3/8" hole under the eaves to run the 20’ cord in.
A bigger question is the size of the garage and expected usage. One circuit from the house is fine for a smaller single car garage where you just want a garage door opener, light, and maybe a few hand tools. Setting up a shop in a 2-3 stall garage will need more power available. Think resale options at this point also. At that point you may want to rerun the power from the house to a circuit box in the garage. 220V, 30-60 amp for heavier loads and multiple circuits. There is a code requirement for grounding in detached buildings IIRC.
Don’t need to get even that fancy for emergency lighting. I have a small device that looks like an overgrown night light for kids bedrooms. But the light stays off until the power goes out. Then a real bright LED comes on to light the area. The rest of the time it charges itself off the outlet it’s plugged into.
Just for further clarification MC is metal clad. By default MC refers to steel sheath. If you want aluminum sheath that is ‘MC Lite’.
If you have the option always use MC Lite. When I was working as a commercial electrician occasionally the spec would be MC and MC lite was unacceptable. Regular MC wire is really heavy in comparison to MC Lite and most manufactures MC wire has more pronounced ridges on the sheath so it catches on everything. The aluminum usually relatively smooth and slides easier.
Actually, I believe ‘Romex’ (NM cable) is not up to code for barns (containing livestock) – concern that the moisture and ammonia in the air will weaken the insulation on the cable, leading to shorts. You have to use type UF (Underground Feeder) in a barn.
Not sure if this is applied by all local inspectors. But the local co-op electric utility was concerned about it.
If there was a livestock barn, given the nature of it, wouldn’t it decay/degrade the casing of MC cable? Or does the galvanization process stop it? Don’t wires slowly degrade inside the casing anyhow, now matter where they are?