Lights at home stuck on, can't turn off...

EsteemedEntity

Woke up this morning to find my hallway lights on. Tried the switch the turn them off, but they stayed on.

There are 4 switches in the hallway that control them (it's a long hallway ). House built in the 70s/80s.

Usually you could just switch any of them to toggle the lights, regardless of how the others were set (as you'd expect).

None of the switches manage to turn the lights off. Different combinations of turning them on and off seem to change the brightness a little. The lights flick on and off ever so briefly (a fraction of a second) when switching any of the switches.

I'm intending to call an electrician to get this sorted. I'm wondering is there any immediate danger or urgency? Should I cut the area off with the circuit breaker? Also wondering what exactly might have gone wrong.

Diggerdunne

Sounds like the switch has arced in the on position and so wont turn off... You are in no immediate danger, more annoying than anything else. Maybe wise to turn off at the breaker once nothin else like alarm or heating is powered from the same breaker...

EsteemedEntity

Ok, will do. Thanks.

EsteemedEntity

Was just on my way to the breakers and the lights started flickering like mad. There was a distinctive sound of electrical arcs from the attic. Got them off with the circuit breaker now...

2011

cathalahern wrote: »

Different combinations of turning them on and off seem to change the brightness a little.

The changing of brightness is because the lights are getting less than mains voltage across them. This is because there is now a volt drop across the light switch. This would indicate that the switch is presenting a larger than normal resistance to the circuit.

I'm wondering is there any immediate danger or urgency?

The only urgency is to switch off the circuit because the additional resistance will have a heating effect. In theory this may have the potential to cause a fire if left switched on. By the sound of it you have taken the correct course of action and isolated the circuit.

Also wondering what exactly might have gone wrong.

I would agree with Diggerdunne, the switch has failed. Time to call an electrician.

Bruthal

Also wondering what exactly might have gone wrong.

If one switch was stuck in the on position, the others should still turn the lights on and off as normal.

The fact the lights briefly go off and back on when switching the switches means the 2 strappers are live the entire time, instead of only one line live at a time, so as the switches flick between both strappers, there is a brief off period. So it sounds like the 2 strappers are connected, probably due to one of the intermediate switches after failing and connecting both strappers together.

The changing brightness is probably because if it is an intermediate switch bridging both strappers, its making a better connection on one strapper than the other, so depending on the positions of the other switches, the lights are a little brighter or dimmer.

It is not certainly an intermediate switch failure, it could be one of the 2 ways, but it is certain both strappers are on together due to being connected together somehow.

Are all 4 switches switching smoothly? If they are then there must be another cause of the strappers being bridged together, a nail into wall? Switch recently changed?

EsteemedEntity

robbie7730 wrote: »

Are all 4 switches switching smoothly? If they are then there must be another cause of the strappers being bridged together, a nail into wall? Switch recently changed?

Switches feel as normal. No recent modifications or nails...

Bruthal

Its unusual, but certainly sounds like both strappers (a wiring method for multi switches) are shorted together somewhere. Very easy for electrician to check that with a multimeter, as at any switch only one of the strapper lines should be live at a time. Still could be a short within one of the intermediate switches, more likely than one of the 2 ways. Simple to confirm or rule out anyway.

A way to confirm the above is to go through all 4 switches and slow as you can switch each one and see do the lights flick off briefly in the middle of the switching movement. If one switch is faulty, it probably wont happen at that one. Sort of hold the top and bottom of each rocker and you might find a position where the lights are off when the switch rocker is half way between on and off.

EsteemedEntity

robbie7730 wrote: »

A way to confirm the above is to go through all 4 switches and slow as you can switch each one and see do the lights flick off briefly in the middle of the switching movement. If one switch is faulty, it probably wont happen at that one. Sort of hold the top and bottom of each rocker and you might find a position where the lights are off when the switch rocker is half way between on and off.

Did this. Interesting results. There are actually 5 switches, I missed one earlier. The lights have also stopped flickering like they did a few hours ago.

When holding the rockers in the half way position for switches 1-4, the lights dim very low (much lower than discussed before), but are still illuminated. The current varies slightly; they flicker, but are never fully off.

When holding rocker 4 half way, the lights are fully off.

Bruthal

cathalahern wrote: »

Did this. Interesting results. There are actually 5 switches, I missed one earlier. The lights have also stopped flickering like they did a few hours ago.

When holding the rockers in the half way position for switches 1-4, the lights dim very low (much lower than discussed before), but are still illuminated. The current varies slightly; they flicker, but are never fully off.

When holding rocker 4 half way, the lights are fully off.

Well it seems like all switches are working properly. Could be some sort of short between wires behind one of the switches then. You could turn off the MCB and check for this by unscrewing the switches from the wall one at a time and inspecting the wiring visually.

You said you heard arcing from attic while the lights were flickering earlier, sometimes its hard to tell where arcing is actually coming from, but maybe there is a junction box in the attic either, and the short between strappers is in there. or it was from one of the switches and sounded like it was from the attic. Its a bungalow?

If there was arcing between strappers due to a short between them, this arcing would stop when you flick any of the switches over, as the arcing is where the strappers are bridged together and are keeping the lights on while the switching positions should have the lights off, but if the switching positions actually had the lights on this arcing would stop.

EsteemedEntity

robbie7730 wrote: »

You could turn off the MCB and check for this by unscrewing the switches from the wall one at a time and inspecting the wiring visually.

Will try this.

robbie7730 wrote: »

Its a bungalow?

Yes.


By the way, thanks for all the comprehensive responses guys!

Davy

cathalahern wrote: »

Will try this.

Dont touch the wiring or the backs of the switches unless you can confirm the loss of voltage

ltdslipdiff

Poltergeist maybe? Sorry unhelpful I know..carry on sparkies !

EsteemedEntity

Didn't seem to be anything wrong with the wires when I looked. I'll just call an electrician tomorrow. Thanks again for all the help.

Bruthal

Davy wrote: »

Dont touch the wiring or the backs of the switches unless you can confirm the loss of voltage

Yes just a visual check, one switch at a time and screw it back up and onto the next one.

Bruthal

Where are you in dublin?

Bruthal

cathalahern wrote: »

Was just on my way to the breakers and the lights started flickering like mad. There was a distinctive sound of electrical arcs from the attic. Got them off with the circuit breaker now...

If you are leaving the MCB on and that arcing happens happens again, you can switch one of the switches and that should stop the arcing if it was between the 2 strappers causing it.

If it was from the attic then its probably the switches have been connected together in a junction box and there is another possible location for the strappers problem.

Bruthal

2011 wrote: »

The changing of brightness is because the lights are getting less than mains voltage across them. This is because there is now a volt drop across the light switch. This would indicate that the switch is presenting a larger than normal resistance to the circuit.

More likely the different brightness is caused because the strappers are connected together by some fault either in a switch (although the switches seem ok from OPs earlier test) or the wiring. So when the switches are set so the light should be off, the light is only on because of the fault between strappers which is probably not a good connection between the strappers, hence the dimming and flickering etc at times.

But when a switch is now switched, the light is now on through the switches instead of the fault between strappers, as switching any switch would now eliminate the fault from the circuit (until a switch is switched again) so now the light will have a proper connection and be brighter.

The fact he said different combinations rather than a single switch caused different brightness supports this.

Anyone can try bridging 2 strappers together and try switching the switches on and off, the light will flicker off briefly as the switch changes between strappers, but cant be switched off.

If you bridge the strappers at any position with a resistor or another bulb as an experiment (or just draw the circuit out), when you switch either 2 ways or intermediates, in one position the main light will be fully on, but switch any switch over and the main light and the bridging bulb will be on in series at half brightness, just like the above fault with both strappers shorted or lightly in contact as it seems here. One switched position has the light on through switches, the other has it off but the bridging fault is keeping the light on through the fault.

A poster said maybe a switch is stuck on, but this should not affect the other switches from switching the light on and off.

Anyway too many drinks so maybe its none of the above:D

crossmolinalad

Had years ago something like that
It was a mouse what did eat pieces out of the wiring at the attic

Bruthal

crossmolinalad wrote: »

Had years ago something like that
It was a mouse what did eat pieces out of the wiring at the attic

Yea it could be something like that, something shorting the 2 way strappers together anyway. Whether it be a faulty intermediate switch, junction box in attic for the lights with a short between strappers, another live wire shorted to and keeping a strapper live although it would still be possible to switch off the light in some switch combinations with that, or strappers mixed up with feed and loop in a 2 way and both strappers put into same terminal etc.

I think mice will actually eat the pvc insulation on wiring.

EsteemedEntity

There's an electrician coming in an hour so hopefully he'll shed some "light" on the situation. I'll let you guys know what it was. Thanks again for the comprehensive replies!

Bruthal

None of the above probably:D

Although some sparks will just change a switch for example, and if it works then thats it, some will want to see what the actual events were that caused the problem. Its an interesting one.

EsteemedEntity

Well, the electrician has come and gone. Spent about 2 hours fiddling around, looked at all the switches, and couldn't pin it down to anything. He said the wiring was pretty bad; no conduits and everything was just plastered over. As some here have already suggested, the strappers and neutral were all live.

Good news is he managed to set it up so that one of the switches manages to turn the lights on and off, but the other 4 are obsolete. He didn't have the equipment with him to investigate any further. We're planning to sell in a few months anyway so no point in having the place rewired now.

Wasn't really impressed with him to be honest. He wasn't very forthcoming with info, you had to ask him a lot to get anything out of him. All his answers were half-hearted mumbles. Anyone know, or is anyone here, a good electrician, for future reference?

Bruthal

cathalahern wrote: »

Well, the electrician has come and gone. Spent about 2 hours fiddling around, looked at all the switches, and couldn't pin it down to anything. He said the wiring was pretty bad; no conduits and everything was just plastered over. As some here have already suggested, the strappers and neutral were all live.

Good news is he managed to set it up so that one of the switches manages to turn the lights on and off, but the other 4 are obsolete. He didn't have the equipment with him to investigate any further. We're planning to sell in a few months anyway so no point in having the place rewired now.

Wasn't really impressed with him to be honest. He wasn't very forthcoming with info, you had to ask him a lot to get anything out of him. All his answers were half-hearted mumbles. Anyone know, or is anyone here, a good electrician, for future reference?

Were are you living. I would of had a look myself. Im in navan but up to blanch regular. All that had to be done to get one light switch working was disconnect one of the strappers at a switch and it will be possible to use a switch to turn them on and off so thats probably what he done.

While it may be hard to find the exact problem location if its within a switch drop , it should be simple to find which switches its between if its not actually one of the switches themselves. That should be straight forward.

EsteemedEntity

robbie7730 wrote: »

Were are you living. I would of had a look myself. Im in navan but up to blanch regular.

That's good of you. I'm in Killiney though, so a good bit out of the way...

Bruthal

cathalahern wrote: »

That's good of you. I'm in Killiney though, so a good bit out of the way...

Is it a bungalow? Strange he said the neutral is live as well. If the light is on properly all the time, how would that be i wonder.

EsteemedEntity

robbie7730 wrote: »

Is it a bungalow? Strange he said the neutral is live as well. If the light is on properly all the time, how would that be i wonder.

It is a bungalow. Not sure how the neutral being live works either. Anyway, it seems sorted for now.

Bruthal

cathalahern wrote: »

It is a bungalow. Not sure how the neutral being live works either. Anyway, it seems sorted for now.

If the light was on all the time, the neutral cant really be showing as live as well as both strappers.

Bruthal

cathalahern wrote: »

It is a bungalow. Not sure how the neutral being live works either. Anyway, it seems sorted for now.

Have to be careful its not an unearthed metal back box behind a switch that has the strappers shorted.

Its not that great leaving a fault not identified anyway.

Sparks 1

Maybe you should have expressed your concerns to the Electrician when he was there instead of complaining about him when he was gone - it gives us Electricians a bad reputation.

Bruthal

Sparks 1 wrote: »

Maybe you should have expressed your concerns to the Electrician when he was there instead of complaining about him when he was gone - it gives us Electricians a bad reputation.

You would think finding which 2 switches the fault is between at least would be simple enough though. Who knows though.