The door in my apartment has been slammed shut at extreme force on more than one occasion (by wind/draft, not anger.) It was slammed so hard, in fact, that the walls and apartment shuddered.
This has me wondering about the electrical wiring contained within the walls. How hard could you slam a door before it starts to damage the electrical wiring in the wall, and what’s the worst that could happen?
If the wiring is properly installed you’d have to slam the door hard enough to knock the wall down to cause a problem. The wires should have room to flex, clearance in holes through the studs, and bushings at the boxes that can absorb normal shaking like a slammed door.
I see. Someone had told me that earthquakes could damage internal wall wiring - I assume he meant something other than outright wall collapse and more like, what shaking or vibrations could do to internal wiring.
Properly wired, I’d really doubt you could do any damage by a single door slam without some other damage, like broken drywall. If it was a constant thing, maybe some vibration could knock something loose, but not the wind blowing the door shut here and there.
The worst that can happen depends on a lot of other things. If everything is wired properly and a bare wire is exposed. Nothing will happen if it’s just floating in there. If it touches a metal junction box, it’ll short out and blow a breaker.
Beyond that is anyone’s guess. What happened? Where did the damage occur? Is it touching anything? Is the damaged spot got hot or sparking? Is it near anything flammable?
In reality, however, it’ll likely short to ground, not touch anything so nothing happens or the connection will separate and open the circuit. It’s not something I’d be particularly concerned about.
In theory, that slam could be the “straw that broke the camel’s back.”
I’ve had outlets fail due to wires coming loose (lazy back-stab outlet installation).
Over time, the wire worked it way loose. Maybe your door slam was the final blow that caused the outlet to fail.
Right, I figure the cables are stapled well enough to not be harmed. The only issue would be if a spliced wire comes loose in one of those what-you-call-it boxes.
Sorry, confused by this part…could you elaborate?
Good handle/topic combo there…
You know, details matter when talking about technical issues like this. Same for all the car related questions sometimes posted here.
I know you said it is an apartment, that is one bit of information, but how old? This would give a better target for what building codes were used at that time. Building and electrical codes are changing all the time. I live in an old house where the electricity was added years after the house was built. But even so, my dad never told us, “you kids stop slamming that door or you’ll but the house down.”
Poorly written sentence. I was attempting to say that it’ll probably
1)short to ground.
2)The live wires won’t touch anything. Left just like that, while unsafe, aren’t going to do anything. It’s like a gun on a bed. Probably not a good place for it, but it’s not going to go off by itself.
3)The wire splice could come apart, which will open (disconnect) the circuit. What ever is downstream of that connection will turn off and then you’ll have a live wire in the box to deal with.
I’m not sure, but possibly 1980s.
Were there ever any building codes that would have allowed a bit of vibration in the structure to create a dangerous situation?
I see. Is the only issue then that the live wire might touch the metal sides of the box?
Depends what you consider an ‘issue’. The boxes are metal and grounded specifically so that a live wire can touch them and blow the breaker. Truthfully, it’s probably the best case scenario. It alerts you to a problem instead of something worse happening.
Knob and tube wiring (used in homes up until the 1930s or so) can more easily get shaken loose over time, and could much more easily short out and cause a fire than could modern wiring.
Knob and tube wiring in general is perfectly legal and it is allowed to remain in place by code as long as it is properly maintained. But as an electrical engineer the stuff just gives me the willies. If I ever had it in my house I would rip it out ASAP. Some insurance companies will also either charge a higher premium or will sometimes even refuse to insure a house with knob and tube wiring.
Aluminum wire is more susceptible to bad connections and such caused by vibration than copper wire, especially at switch and outlet connections. These days, pigtails are required to be attached to the aluminum wire instead of directly connecting the aluminum wire to an outlet or switch, but direct connections were originally allowed when aluminum wire was first used. If your home was built in the late 60s or early 70s, you might have aluminum wire and you might have issues with bad connections, which could be made worse by vibrations.
Very old wiring might also have paper or fabric insulation which could be degraded from age. A lot of vibration could shake the wires around until they touch and short out, resulting in a possible fire hazard.
For anything built in the 1980s and later, probably the only potential issue is a wire working its way loose from a screw terminal on a switch or an outlet and possibly shorting out and causing a fire. Or possibly those god-awful backstab connectors working their way loose (another thing I refuse to have in any house I own).
What’s the alternative to having a backstab connector?
But this is a door slamming, not living next to the L train. That’s what I meant when I said ‘a bit of vibration’.
Door slamming = orders of magnitude stronger right?
Edit: Ok, apparently 1985.
Vibration like this could cause 2 types of problems: opens & shorts.
Opens happen when the vibration shakes loose wires in a junction box, or shakes wires loose from their connection to a switch or receptacle. Then something will stop working: the switch won’t turn on the light, the outlet is dead, etc. That’s not really too much of a risk, and you will probably notice it quickly. But depending on how your house is wired, it could be things in the next room that stop working.
Shorts are more serious, in that a live hot wire could be shaken loose and touch a neutral or ground wire. This causes a short circuit, with sparks & heat. But that’s what fuses/circuit breakers are designed to stop, and they should break within a second or two. Then again, things will not work, and you will notice that.
There are a couple of rare possibilities that could be more dangerous.
If wires get shaken loose, but not so loose that they lose contact, it could still work, but have a weak connection. That could cause the connection to heat up when it’s on, and might cause a fire. But things inside an electrical box are all designed to withstand high heat, so this is unlikely. There isn’t much that you would notice about this, except a switch or outlet that seems too warm, or that is intermittent – you have to wiggle the plug in the outlet or the switch to get it to work. Both these are things that should have you get the wiring checked soon.
The other possibility is if a live wire comes loose, and touches a metal box that is NOT properly grounded (and older houses (pre-1962) often didn’t have 3-wire grounding). Then if you happen to touch the metal box, or metal screws holding the switch or outlet to the box, and at the same time are yourself grounded (like standing in a wet shower or touching a metal plumbing pipe), the circuit would be completed through you, and you would get a shock, and that could cause injury or even death. So getting a shock (other than static electricity) from any electrical wiring should lead to having the wiring checked immediately.