I was replacing an electrical socket in my (UK) house, and I noticed that the previous occupant had wired live and neutral backwards. However, I've used a variety of appliances and devices on that socket in the past without any issue.

So - does it actually matter which way around they are connected? As long as you obviously don't connect live from one part of the ring with neutral from the other, what difference does it make?

  • Yep - it's a similar question, but it doesn't really give a straight answer. Does it matter - if so, why?
    – xorsyst
    Commented Apr 27, 2015 at 13:53
  • 1
    The answer is fairly clear. Yes it matters, because it reduces the possibility of an appliance/device becoming a shock hazard.
    – Tester101
    Commented Apr 27, 2015 at 13:59
  • Thanks - but why does it? Why does having them the wrong way around make something a shock hazard?
    – xorsyst
    Commented Apr 28, 2015 at 8:25
  • 1
    Because when it's the wrong way around, the device is energized (the internal wiring is at a voltage potential higher than 0). So if there's a fault somewhere, you could potentially become a path to ground. Also in some older appliances, the grounded (neutral) conductor was bonded to the chassis of the device. If this type of appliance was plugged into a reversed receptacle, the entire chassis would be energized.
    – Tester101
    Commented Apr 28, 2015 at 11:21
  • Live/neutral swap plus neutral earth swap = live case. Either on its own, no immediate hazard. Commented Jul 2, 2018 at 8:15

1 Answer 1


Not for many appliances, but for some that are sensitive it could cause problems.

  • many UPSes will refuse to accept it
    – Skaperen
    Commented Apr 27, 2015 at 11:51
  • 3
    for function, backwards often works, but for safety it is always a bad idea ... do it right
    – Skaperen
    Commented Apr 27, 2015 at 11:53

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