How to use an RCD socket?
November 9, 2019 9:26 AM Subscribe
My rented garage has this RCD power socket installed (or at least one that looks identical). It's acting like it's permanently tripped. Am I just using it wrong?
Yes, this is a stupid question. But "how to use a plug socket" is unfortunately too obvious for anyone to have written up a handy guide to check myself against.
This is a question about UK sockets specifically, but I suspect it's pretty universal.
What I think should happen:
0) The power socket is off, with a black indicator behind the little window. All is peaceful.
1) I plug something into one of the sockets
2) I press and release the "power" button
3) The little window shows a red "on" indicator, which stays in place
4) I switch on my appliance and... it works. Things get heated, cut, vacuumed, charged, etc. There is much joy to be had.
5) Pressing the "reset" button (or a power cut, or a fault in my appliance's wiring) trips the RCD, turning the power off.
What actually happens is that when I release the power button, I see the red "on" indicator for a fraction of a second (it's mechanical - a bit of coloured plastic moving behind the window, not a light) before it clicks back to the "off" state. It's not latching on then switching off, it's just passing through the "on" state as the button moves. I sometimes get an instant of power from the socket as it passes through the on state (e.g. the phone charger's LED blinks on), so I know there's power to the socket, but it never latches "on".
I don't think it can be a problem with what I'm plugging in: I've tried a heat gun (brand new), a jigsaw (brand new), a vacuum cleaner (recently passed a PAT test) and a phone charger. These all work perfectly in sockets in my flat. I've also tried it with nothing plugged in, and it behaves exactly the same.
From my understanding of what RCD sockets are supposed to do, I assumed this means it's faulty. However, I contacted my landlord who says they sent an electrician who tested it while I was out, and found it to be working perfectly.
So:
a) Is my expectation of how RCD sockets should work correct?
b) If not, how *should* I be using this thing?
c) Specifically, should I be able to switch it on (and have it stay on) without anything plugged into it? Or something that's plugged in but switched off?
d) If it seems there's a problem, is there anything I can do to further diagnose this before I start arguing with my landlord about whether this electrician they sent actually exists?
To forestall the obvious warnings: I have no intention of taking this thing apart or interacting with the mains supply beyond plugging stuff into sockets. Aside from anything else, if I fatally electrocute myself I'd probably lose the cleaning deposit.
Yes, this is a stupid question. But "how to use a plug socket" is unfortunately too obvious for anyone to have written up a handy guide to check myself against.
This is a question about UK sockets specifically, but I suspect it's pretty universal.
What I think should happen:
0) The power socket is off, with a black indicator behind the little window. All is peaceful.
1) I plug something into one of the sockets
2) I press and release the "power" button
3) The little window shows a red "on" indicator, which stays in place
4) I switch on my appliance and... it works. Things get heated, cut, vacuumed, charged, etc. There is much joy to be had.
5) Pressing the "reset" button (or a power cut, or a fault in my appliance's wiring) trips the RCD, turning the power off.
What actually happens is that when I release the power button, I see the red "on" indicator for a fraction of a second (it's mechanical - a bit of coloured plastic moving behind the window, not a light) before it clicks back to the "off" state. It's not latching on then switching off, it's just passing through the "on" state as the button moves. I sometimes get an instant of power from the socket as it passes through the on state (e.g. the phone charger's LED blinks on), so I know there's power to the socket, but it never latches "on".
I don't think it can be a problem with what I'm plugging in: I've tried a heat gun (brand new), a jigsaw (brand new), a vacuum cleaner (recently passed a PAT test) and a phone charger. These all work perfectly in sockets in my flat. I've also tried it with nothing plugged in, and it behaves exactly the same.
From my understanding of what RCD sockets are supposed to do, I assumed this means it's faulty. However, I contacted my landlord who says they sent an electrician who tested it while I was out, and found it to be working perfectly.
So:
a) Is my expectation of how RCD sockets should work correct?
b) If not, how *should* I be using this thing?
c) Specifically, should I be able to switch it on (and have it stay on) without anything plugged into it? Or something that's plugged in but switched off?
d) If it seems there's a problem, is there anything I can do to further diagnose this before I start arguing with my landlord about whether this electrician they sent actually exists?
To forestall the obvious warnings: I have no intention of taking this thing apart or interacting with the mains supply beyond plugging stuff into sockets. Aside from anything else, if I fatally electrocute myself I'd probably lose the cleaning deposit.
Best answer: "An RCD constantly monitors the electric current flowing through one or more circuits it is used to protect. If it detects electricity flowing down an unintended path, such as through a person who has touched a live part, the RCD will switch the circuit off very quickly..."
It should be able to be switched on and stay on with nothing plugged into it. If it trips immediately, then there is a ground fault or the device is defective or damaged or it is improperly wired. Talk to the landlord.
posted by the Real Dan at 9:43 AM on November 9, 2019 [1 favorite]
It should be able to be switched on and stay on with nothing plugged into it. If it trips immediately, then there is a ground fault or the device is defective or damaged or it is improperly wired. Talk to the landlord.
posted by the Real Dan at 9:43 AM on November 9, 2019 [1 favorite]
Best answer: Either the RCD is broken or it's working and correctly cutting off the current due to a fault elsewhere. Either way the landlord needs to call an electrician.
posted by EndsOfInvention at 9:45 AM on November 9, 2019
posted by EndsOfInvention at 9:45 AM on November 9, 2019
Best answer: a) Is my expectation of how RCD sockets should work correct?
Yes.
c) Specifically, should I be able to switch it on (and have it stay on) without anything plugged into it?
Yes.
Or something that's plugged in but switched off?
Yes.
d) If it seems there's a problem, is there anything I can do to further diagnose this before I start arguing with my landlord about whether this electrician they sent actually exists?
Diagnose? No. Just take a short snippet of phone footage that shows you turning the thing on with nothing plugged in and having it immediately trip. That's not normal, and video that shows it failing with nothing of yours plugged into it is going to deprive your landlord of any grounds to argue about it.
You can leave the question of the existence of the landlord's electrician open, because you have nothing to gain by calling the landlord a liar to their face. Regardless of whether it ever was working, it isn't working now, as your footage will clearly show; and getting it fixed is certainly your landlord's responsibility.
posted by flabdablet at 10:11 AM on November 9, 2019 [2 favorites]
Yes.
c) Specifically, should I be able to switch it on (and have it stay on) without anything plugged into it?
Yes.
Or something that's plugged in but switched off?
Yes.
d) If it seems there's a problem, is there anything I can do to further diagnose this before I start arguing with my landlord about whether this electrician they sent actually exists?
Diagnose? No. Just take a short snippet of phone footage that shows you turning the thing on with nothing plugged in and having it immediately trip. That's not normal, and video that shows it failing with nothing of yours plugged into it is going to deprive your landlord of any grounds to argue about it.
You can leave the question of the existence of the landlord's electrician open, because you have nothing to gain by calling the landlord a liar to their face. Regardless of whether it ever was working, it isn't working now, as your footage will clearly show; and getting it fixed is certainly your landlord's responsibility.
posted by flabdablet at 10:11 AM on November 9, 2019 [2 favorites]
Best answer: I would echo what RustyBrooks said. Make sure you push the power button firmly until it bottoms out solidly. Don't assume that just because you see the red indicator that you have pushed the button far enough. Sometimes that means pushing the button with the tip of your finger even below the surface of face.
If that doesn't fix it, then I agree that the device is probably faulty.
posted by JackFlash at 11:56 AM on November 9, 2019 [2 favorites]
If that doesn't fix it, then I agree that the device is probably faulty.
posted by JackFlash at 11:56 AM on November 9, 2019 [2 favorites]
Response by poster: Well, that's pretty resounding. It sounds like it should work the way I expected it to, and that I'm probably right to think it's faulty. I wouldn't have doubted it, but I was thrown off by my landlord saying that their electrician had tested it and said it's perfect.
I'm pretty sure I'm pressing it far enough- it goes in about 1cm (2/5 inch) then reaches a hard stop. If I hold it there I can hear a very faint buzzing sound which might not be healthy (or possibly just the coils on the live and neutral wires vibrating?) but at least seems to confirm that there's some electrical contact being made.
The reset button goes less deep -- about 5mm -- which at first made me wonder whether there was a problem with it (if it were permanently closed it'd explain the behaviour), but it springs back and moves freely above that depth so I think it's probably fine. Regardless, jiggling it around doesn't help so if it is broken there's nothing much I can do.
I've emailed my landlord again, including a video of me pressing the button without anything plugged in. Hopefully I can talk directly with the electrician.
posted by metaBugs at 2:33 AM on November 10, 2019
I'm pretty sure I'm pressing it far enough- it goes in about 1cm (2/5 inch) then reaches a hard stop. If I hold it there I can hear a very faint buzzing sound which might not be healthy (or possibly just the coils on the live and neutral wires vibrating?) but at least seems to confirm that there's some electrical contact being made.
The reset button goes less deep -- about 5mm -- which at first made me wonder whether there was a problem with it (if it were permanently closed it'd explain the behaviour), but it springs back and moves freely above that depth so I think it's probably fine. Regardless, jiggling it around doesn't help so if it is broken there's nothing much I can do.
I've emailed my landlord again, including a video of me pressing the button without anything plugged in. Hopefully I can talk directly with the electrician.
posted by metaBugs at 2:33 AM on November 10, 2019
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posted by RustyBrooks at 9:43 AM on November 9, 2019 [1 favorite]