Moved into an old house from 1950s, in Austria. The wiring is fairly old, I assume. In the upstairs master bedroom I replaced the ceiling light fixture today. There are three wires, one blue and two grey - which I’ve never seen before and installed the lighting fixture, after i assumed that one of the grey wires as the Earth wire.

I had to drill two 6mm holes in the ceiling and use plugs for the fixture. Although I didn’t use a wire detector, it didn’t seem like i drilled through any wires. Once i put in a Bulb, the light fixture seems to work fine. But now some of the the lights and outlets that are on the same circuit are no longer working.

I will call an electrician tommorow - but was just wondering if anyone might have an idea what it could be? A short circuit? I left the breaker off in case there is a risk of fire etc., any other safety precautions I could take?

  • I’m from UK originally, and ground is also green with Yellow stripe. This is two grey wires which are exactly the same colour. The fixture that was in before was a multiple light, and both grey wires went into the same input. Input not big enough on this fixture. It seemed to work ok when I connected one grey wire to ground input. However, when i found that other lights were not not working I removed the newfixture and disconnected everything - but those other lights still dont work. Also there was nothing connected to it before - I removed the old light fixture when I was painting a while ago
    – Udawg
    Commented Jun 25, 2023 at 21:07
  • Beyond that, maybe a picture of the actual house wiring, the new lamp wiring, and the instructions may be useful for getting you a good answer.
    – FreeMan
    Commented Jun 25, 2023 at 21:21
  • Thanks mate, I think you might be right. I will post some pics tommorow, but late here at the moment. The two grey wires went into the same input, so perhaps they either need to be combined - like they were before on the previous input - or I need to get a three input connector. The thing is when I switched it on it never tripped the breaker etc. Everything is disconnected now, so will it be ok if I just leave that circuit off over night?
    – Udawg
    Commented Jun 25, 2023 at 21:28
  • You're fine leaving the breaker off over night. Unless, of course, there is something critical on that circuit (fridge, medical equipment, etc.). If there is, use an extension cord to plug it into a working circuit for the night.
    – FreeMan
    Commented Jun 25, 2023 at 21:29
  • No it’s just lights - all good. Thanks!
    – Udawg
    Commented Jun 25, 2023 at 21:33

1 Answer 1


To consolidate the comments into an answer:

How was it wired before you removed the old fixture? That is, most likely, exactly how you should have wired in the new one. My guess is that you left one of the grey wires disconnected, and that's the one that takes power to the things now not working. Also, if grey was ground, there's a very strong chance it was wired incorrectly. I'm in the US, but I believe it's universal world-wide that a ground wire is one of

  • Bare,
  • Green, or
  • Green with a Yellow Stripe

If the connector on the new fixture doesn't have room for the two wires, the solution would be to get another connector that can handle 3 wires - the two grey ones from the ceiling and the one (whatever color) coming from the fixture. Again, though, I'm 99.99% certain that grey shouldn't be ground and that when you connected it that way, you energized the portion of the house wiring that's never supposed to have power on it except in an emergency/error situation. This is dangerous.

Earth/ground has nothing to do with the type of bulb in use, but is dependent on the device. If the device itself does not have a ground connection, then it has (or at least should have been) certified by your national electrical safety body (it should have a BSA Kitemark logo since you're in the UK) as not needing a ground. If it does have a ground wire/screw terminal, then you definitely should use it. (Of course, that's dependent on there being a ground to the box the device is attached to, and if it doesn't have a ground, it probably should.)

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