My apartment lights dim briefly when the elevator starts running
January 4, 2016 5:52 PM Subscribe
Should I be concerned that my apartment lights dim momentarily when the building’s elevator is activated?
I rent an apartment in a four-story building with a hydroelectric elevator in San Francisco, California. Electricity is provided by PG&E. When the elevator car begins moving between floors, the lights in my apartment dim for a fraction of a second. My understanding of the issue is that an electrical circuit may be overloaded.
I’m more concerned about my appliances and less concerned about the lights; the dimming of the lights is simply how I observe the issue. Some of my electronics are plugged into surge-protecting power strips, but the problem seems more like a temporary drop in voltage rather than a surge.
If this is something I should be concerned about, how should I raise the issue with the building’s owner? What problems could result by not resolving this?
I rent an apartment in a four-story building with a hydroelectric elevator in San Francisco, California. Electricity is provided by PG&E. When the elevator car begins moving between floors, the lights in my apartment dim for a fraction of a second. My understanding of the issue is that an electrical circuit may be overloaded.
I’m more concerned about my appliances and less concerned about the lights; the dimming of the lights is simply how I observe the issue. Some of my electronics are plugged into surge-protecting power strips, but the problem seems more like a temporary drop in voltage rather than a surge.
If this is something I should be concerned about, how should I raise the issue with the building’s owner? What problems could result by not resolving this?
There isn't really anything the owner can do about it. PomPomTom is correct that it can make your computers reboot.
If you're concerned about it, buy a UPS for your computer system. Stabilizing the voltage is one of the things they do.
Surge protectors don't affect under-voltage.
posted by Chocolate Pickle at 7:25 PM on January 4, 2016 [1 favorite]
If you're concerned about it, buy a UPS for your computer system. Stabilizing the voltage is one of the things they do.
Surge protectors don't affect under-voltage.
posted by Chocolate Pickle at 7:25 PM on January 4, 2016 [1 favorite]
Best answer: This is not an act of God. Of course there's something the building owner can do. They can spend a likely large sum of money getting the building's electrical service and distribution properly sized and balanced. But, they probably won't.
Complain to the building owner but also get a UPS on critical electronics and don't hold your breath.
posted by meinvt at 7:38 PM on January 4, 2016 [4 favorites]
Complain to the building owner but also get a UPS on critical electronics and don't hold your breath.
posted by meinvt at 7:38 PM on January 4, 2016 [4 favorites]
You might want to check the electric meter for your apartment before and after someone rides the elevator just to make sure that the elevator isn't wired through your apartment :-)
posted by monotreme at 7:56 PM on January 4, 2016 [6 favorites]
posted by monotreme at 7:56 PM on January 4, 2016 [6 favorites]
I wouldn't be concerned. A large induction motor for an elevator can draw five times its normal current for the first second or two while it comes up to speed -- 100 or 200 amps or more. This large current draw can cause a brief voltage drop in the building wiring. It is not dangerous. The circuit breakers are designed to handle 10 times normal current for the first second and up to 5 times normal current for the first 10 seconds. A brief dimming for less than a second is nothing to be worried about.
posted by JackFlash at 9:48 PM on January 4, 2016 [5 favorites]
posted by JackFlash at 9:48 PM on January 4, 2016 [5 favorites]
You might want to check the electric meter for your apartment before and after someone rides the elevator just to make sure that the elevator isn't wired through your apartment.
This is unlikely. The elevator motor is most likely three-phase, with its own meter, while the residential circuits are separately metered split-phase 120V and 240V. This is called high-leg-delta, in which they all share a common three-phase service entrance, hence the dimming when the elevator motor kicks on, but must be metered separately downstream where they are split out.
posted by JackFlash at 12:50 PM on January 5, 2016 [2 favorites]
This is unlikely. The elevator motor is most likely three-phase, with its own meter, while the residential circuits are separately metered split-phase 120V and 240V. This is called high-leg-delta, in which they all share a common three-phase service entrance, hence the dimming when the elevator motor kicks on, but must be metered separately downstream where they are split out.
posted by JackFlash at 12:50 PM on January 5, 2016 [2 favorites]
My building doesn't have an elevator, but has issues like this(and flakey power in general).
It killed two of my computers. Like, completely ruined dead. Fried power supplies, fried motherboards. I bought a quality line-interactive UPS(a standby UPS, which most cheap ones are, won't help here. look for "line interactive" in the description) when i got a new one for the second time. I've recommended them to anyone who mentioned power issues like this since then.
It's well known that hydraulic elevators have a really high start current draw. Most newer buildings account for this, but if it was added on later or put in to replace a different one that could be part of the issue.
But regardless, get a good UPS. Get a second one for your TV/etc too.
Another issue can also be the power spiking up higher than normal once the momentary load goes away... which a line interactive UPS will also protect against. It's STUPID how often i hear mine kick on. You'll probably be surprised if you get one.
posted by emptythought at 2:49 PM on January 5, 2016
It killed two of my computers. Like, completely ruined dead. Fried power supplies, fried motherboards. I bought a quality line-interactive UPS(a standby UPS, which most cheap ones are, won't help here. look for "line interactive" in the description) when i got a new one for the second time. I've recommended them to anyone who mentioned power issues like this since then.
It's well known that hydraulic elevators have a really high start current draw. Most newer buildings account for this, but if it was added on later or put in to replace a different one that could be part of the issue.
But regardless, get a good UPS. Get a second one for your TV/etc too.
Another issue can also be the power spiking up higher than normal once the momentary load goes away... which a line interactive UPS will also protect against. It's STUPID how often i hear mine kick on. You'll probably be surprised if you get one.
posted by emptythought at 2:49 PM on January 5, 2016
Response by poster: Thanks, all. There are individual meters within the building that I could watch, but like JackFlash states, it's unlikely that the elevator is on my meter. I can raise the issue with the owner to see where it goes. One computer and some external hard drives could be moved to an uninterruptible power supply.
The elevator seems to be part of the original design of the building, but of course the machinery could be newer.
What might happen to the TV when the voltage drops? (Sharp LED model)
posted by germdisco at 4:31 PM on January 5, 2016
The elevator seems to be part of the original design of the building, but of course the machinery could be newer.
What might happen to the TV when the voltage drops? (Sharp LED model)
posted by germdisco at 4:31 PM on January 5, 2016
This thread is closed to new comments.
If you have large voltage drops, it may be that your computer(s) will reboot - and not gracefully.
posted by pompomtom at 7:13 PM on January 4, 2016