I noticed a slight fizzling sound when I turned on the landing light.
So, I undid the switch and had a look inside.

First of all, I should say it was a double switch. One side was for two
way switching to the floor above, and the other side was three way
switching for this floor. That's an awful lot of wires to cram into a
back box, even quite a deep one.

Anyway, it turned out that two of the conductors were completely loose.
They pulled out as soon as I eased the switch away from the wall. Also,
the earth wire was loose, although it stayed in its terminal.

This switch was fitted in 1998, and AFAIK it had not been touched since.
It has worked fine since then, and it's working now since I tightened it
up. So, what's going on?

My guess is that it's all so congested with all those cables that it was
never properly tightened in the first place. But, how come it's worked
okay for 20 years?

On Thursday, 5 December 2019 11:46:32 UTC, GB wrote:
I noticed a slight fizzling sound when I turned on the landing light.
So, I undid the switch and had a look inside.

First of all, I should say it was a double switch. One side was for two
way switching to the floor above, and the other side was three way
switching for this floor. That's an awful lot of wires to cram into a
back box, even quite a deep one.

Anyway, it turned out that two of the conductors were completely loose.
They pulled out as soon as I eased the switch away from the wall. Also,
the earth wire was loose, although it stayed in its terminal.

This switch was fitted in 1998, and AFAIK it had not been touched since.
It has worked fine since then, and it's working now since I tightened it
up. So, what's going on?

My guess is that it's all so congested with all those cables that it was
never properly tightened in the first place. But, how come it's worked
okay for 20 years?

Brexit :-)

Anyway, the conductors have been loosening over time, but not so much to degrade the connection, until just now when critical level of resistance was obtained and it started fizzing.

Could even have been because it's colder today.

Owain

On 05/12/2019 12:02, Jethro_uk wrote:


Repeated mechanical shock of heating/cooling (exacerbated by arcing if
the wires were loose to start with) leading to the screw slowly following
the thread ?

Is that why, spring, wago style connectors are mandated for inaccessible
junctions.

On 2019-12-05, Pancho wrote:

On 05/12/2019 12:02, Jethro_uk wrote:


Repeated mechanical shock of heating/cooling (exacerbated by arcing if
the wires were loose to start with) leading to the screw slowly following
the thread ?

Is that why, spring, wago style connectors are mandated for inaccessible
junctions.

....and that's today's holy war started!

"Jethro_uk" wrote in message
...
On Thu, 05 Dec 2019 11:46:28 +0000, GB wrote:

I noticed a slight fizzling sound when I turned on the landing light.
So, I undid the switch and had a look inside.

First of all, I should say it was a double switch. One side was for two
way switching to the floor above, and the other side was three way
switching for this floor. That's an awful lot of wires to cram into a
back box, even quite a deep one.

Anyway, it turned out that two of the conductors were completely loose.
They pulled out as soon as I eased the switch away from the wall. Also,
the earth wire was loose, although it stayed in its terminal.

This switch was fitted in 1998, and AFAIK it had not been touched since.
It has worked fine since then, and it's working now since I tightened it
up. So, what's going on?

My guess is that it's all so congested with all those cables that it was
never properly tightened in the first place. But, how come it's worked
okay for 20 years?

Repeated mechanical shock of heating/cooling (exacerbated by arcing if
the wires were loose to start with) leading to the screw slowly following
the thread ?

If it was that they'd all be loose in the house. None of mine are and
they were done in 1972. Much more likely that whoever did that
one forgot to tighten the screws and the contact was good enough
to work fine for 20 years until repeated heating due to a less that
tight contact ended up with too much corrosion and arcing.

On Thursday, 5 December 2019 12:07:51 UTC, Pancho wrote:
On 05/12/2019 12:02, Jethro_uk wrote:


Repeated mechanical shock of heating/cooling (exacerbated by arcing if
the wires were loose to start with) leading to the screw slowly following
the thread ?

Is that why, spring, wago style connectors are mandated for inaccessible
junctions.

Yes, surely you shouldn't be using spring connectors in autumn.

On 05/12/2019 14:46, Ray wrote:


"Jethro_uk" wrote in message
...
On Thu, 05 Dec 2019 11:46:28 +0000, GB wrote:

I noticed a slight fizzling sound when I turned on the landing light.
So, I undid the switch and had a look inside.

First of all, I should say it was a double switch. One side was for two
way switching to the floor above, and the other side was three way
switching for this floor. That's an awful lot of wires to cram into a
back box, even quite a deep one.

Anyway, it turned out that two of the conductors were completely loose.
They pulled out as soon as I eased the switch away from the wall. Also,
the earth wire was loose, although it stayed in its terminal.

This switch was fitted in 1998, and AFAIK it had not been touched since.
It has worked fine since then, and it's working now since I tightened it
up. So, what's going on?

My guess is that it's all so congested with all those cables that it was
never properly tightened in the first place. But, how come it's worked
okay for 20 years?

Repeated mechanical shock of heating/cooling (exacerbated by arcing if
the wires were loose to start with) leading to the screw slowly following
the thread ?

If it was that they'd all be loose in the house. None of mine are and
they were done in 1972. Much more likely that whoever did that
one forgot to tighten the screws and the contact was good enough
to work fine for 20 years until repeated heating due to a less that
tight contact ended up with too much corrosion and arcing.

There can't be a lot of heating on a lighting circuit. I suppose there's
a bit of vibration every time the switch is turned off and on.

Its the juxtaposition of the wires in the holes, then as the copper squashes
eventually something gets unwedged and the connection is loose. Seen it on
sockets as well. Indeed any electrical connection seems to suffer from this
if there are multiple wires in a hole.
Brian

--
----- --
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please
Note this Signature is meaningless.!
"GB" wrote in message
...
I noticed a slight fizzling sound when I turned on the landing light. So, I
undid the switch and had a look inside.

First of all, I should say it was a double switch. One side was for two
way switching to the floor above, and the other side was three way
switching for this floor. That's an awful lot of wires to cram into a back
box, even quite a deep one.

Anyway, it turned out that two of the conductors were completely loose.
They pulled out as soon as I eased the switch away from the wall. Also,
the earth wire was loose, although it stayed in its terminal.

This switch was fitted in 1998, and AFAIK it had not been touched since.
It has worked fine since then, and it's working now since I tightened it
up. So, what's going on?

My guess is that it's all so congested with all those cables that it was
never properly tightened in the first place. But, how come it's worked
okay for 20 years?

"GB" wrote in message
...
On 05/12/2019 14:46, Ray wrote:


"Jethro_uk" wrote in message
...
On Thu, 05 Dec 2019 11:46:28 +0000, GB wrote:

I noticed a slight fizzling sound when I turned on the landing light.
So, I undid the switch and had a look inside.

First of all, I should say it was a double switch. One side was for two
way switching to the floor above, and the other side was three way
switching for this floor. That's an awful lot of wires to cram into a
back box, even quite a deep one.

Anyway, it turned out that two of the conductors were completely loose.
They pulled out as soon as I eased the switch away from the wall. Also,
the earth wire was loose, although it stayed in its terminal.

This switch was fitted in 1998, and AFAIK it had not been touched
since.
It has worked fine since then, and it's working now since I tightened
it
up. So, what's going on?

My guess is that it's all so congested with all those cables that it
was
never properly tightened in the first place. But, how come it's worked
okay for 20 years?

Repeated mechanical shock of heating/cooling (exacerbated by arcing if
the wires were loose to start with) leading to the screw slowly
following
the thread ?

If it was that they'd all be loose in the house. None of mine are and
they were done in 1972. Much more likely that whoever did that
one forgot to tighten the screws and the contact was good enough
to work fine for 20 years until repeated heating due to a less that
tight contact ended up with too much corrosion and arcing.

There can't be a lot of heating on a lighting circuit.

There is with mine,, I used to use 150W PAR38s before I change to Hue leds,

I suppose there's a bit of vibration every time the switch is turned off
and on.

Doesnt explain why mine did much longer with no loosening.

Can attest to screw connections working loose over time. I recently posted about a junction box I had installed on a floor joist about 5years ago only to find when I added a spur to it I found the screws gripping OK but definitely not tightened to my usual torque of one grunt + 1. At the moment it is easily accessible as the floor is carpeted but SWAMBO is talking about replacing the covering with Amtico or Karndean so will probably replace it with a Wago box before that.

Richard

"Brian Gaff (Sofa 2)" wrote in message
...
Its the juxtaposition of the wires in the holes, then as the copper
squashes eventually something gets unwedged and the connection is loose.
Seen it on sockets as well. Indeed any electrical connection seems to
suffer from this if there are multiple wires in a hole.

Doesn’t happen here and almost all the terminals have multiple wires in the
holes.

"GB" wrote in message
...
I noticed a slight fizzling sound when I turned on the landing light. So,
I undid the switch and had a look inside.

First of all, I should say it was a double switch. One side was for two
way switching to the floor above, and the other side was three way
switching for this floor. That's an awful lot of wires to cram into a
back box, even quite a deep one.

Anyway, it turned out that two of the conductors were completely loose.
They pulled out as soon as I eased the switch away from the wall. Also,
the earth wire was loose, although it stayed in its terminal.

This switch was fitted in 1998, and AFAIK it had not been touched since.
It has worked fine since then, and it's working now since I tightened it
up. So, what's going on?

My guess is that it's all so congested with all those cables that it was
never properly tightened in the first place. But, how come it's worked
okay for 20 years?

On Thu, 5 Dec 2019 06:47:29 -0800 (PST), whisky-dave wrote:

On Thursday, 5 December 2019 12:07:51 UTC, Pancho wrote:
On 05/12/2019 12:02, Jethro_uk wrote:


Repeated mechanical shock of heating/cooling (exacerbated by arcing if
the wires were loose to start with) leading to the screw slowly following
the thread ?

Is that why, spring, wago style connectors are mandated for inaccessible
junctions.

Yes, surely you shouldn't be using spring connectors in autumn.

"'tis the Winter of our disconnect..."
--
Peter.
The gods will stay away
whilst religions hold sway

On Fri, 6 Dec 2019 01:46:52 +1100, Ray, better known as cantankerous
trolling senile geezer Rodent Speed, wrote:

FLUSH the sleepless senile idiot's latest troll**** unread

01:46??? LOL

--
Website (from 2007) dedicated to the 85-year-old trolling senile
cretin from Oz:
https://www.pcreview.co.uk/threads/r...d-faq.2973853/

On Fri, 6 Dec 2019 02:17:32 +1100, Ray, better known as cantankerous
trolling senile geezer Rodent Speed, wrote:

FLUSH the sleepless, trolling senile asshole's latest troll**** unread

02:17??? LOL Just swallow your Nembutal finally, you useless idiot! Or what
did you buy it for? tsk

--
dennis@home to retarded senile Rot:
"sod off rod you don't have a clue about anything."
Message-ID:

On Fri, 6 Dec 2019 02:33:09 +1100, cantankerous trolling geezer Rodent
Speed, the auto-contradicting senile sociopath, blabbered, again:

FLUSH senile idiot's latest troll****

02:33??? AGAIN? LOL

--
addressing nym-shifting senile Rodent:
"You on the other hand are a heavyweight bull****ter who demonstrates
your particular prowess at it every day."
MID:

"Adam Funk" wrote in message
...
On 2019-12-05, Pancho wrote:

On 05/12/2019 12:02, Jethro_uk wrote:


Repeated mechanical shock of heating/cooling (exacerbated by arcing if
the wires were loose to start with) leading to the screw slowly
following
the thread ?

Is that why, spring, wago style connectors are mandated for inaccessible
junctions.

...and that's today's holy war started!

I bought lots of GU10 light fittings. Each one was supplied with a spring
connector for the incoming wires, and permanent connections to the fitting.

The spring connectors were just about OK for single twin-and-earth
solid-core wires: the springs retained the wires OK. But some of the
existing fittings that I was replacing had two or even three sets of T&E
going to the screw-terminal junction boxes. The springs were nowhere near
strong enough to retain two or three solid-core wires: at least one wire
would always pull loose.

I quickly learned that the spring connectors were not up to the job, so I
cut each one off and used the existing screw-terminal junction boxes. Much
more secure and certain to clamp all the wires - but I will check them every
few years to make sure that the screws aren't working loose...

So I'm in the screw-is-better-than-spring camp ;-)

Brian Gaff wrote:

any electrical connection seems to suffer from this
if there are multiple wires in a hole

An argument in favour of Wago connectors, with a hole per wire.

On Fri, 6 Dec 2019 10:21:46 +0000, Andy Burns wrote:

any electrical connection seems to suffer from this if there are
multiple wires in a hole

An argument in favour of Wago connectors, with a hole per wire.

I though wago and similar spring connectors were stricly 1 wire per
hole. That fact that the larger sizes can accept more than one
smaller wire was improper use. You might get away with two wires but
three or more is asking for trouble.

--
Cheers
Dave.

Dave Liquorice wrote:

Andy Burns wrote:

An argument in favour of Wago connectors, with a hole per wire.

I though wago and similar spring connectors were stricly 1 wire per
hole. That fact that the larger sizes can accept more than one
smaller wire was improper use.

I'd say so.

On 06/12/2019 10:21, Andy Burns wrote:
Brian Gaff wrote:

any electrical connection seems to suffer from this
if there are multiple wires in a hole

An argument in favour of Wago connectors, with a hole per wire.


Or fit an AFDD that does not work?

--
Adam

On Friday, December 6, 2019 at 2:19:36 AM UTC+11, Tricky Dicky wrote:
Can attest to screw connections working loose over time. I recently posted about a junction box I had installed on a floor joist about 5years ago only to find when I added a spur to it I found the screws gripping OK but definitely not tightened to my usual torque of one grunt + 1. At the moment it is easily accessible as the floor is carpeted but SWAMBO is talking about replacing the covering with Amtico or Karndean so will probably replace it with a Wago box before that.

Richard

Screw connections tend to loosen over temperature cycles, vibration in the frame ie.,a large "thud" of a tree felling, roadside rammer or even a mild land tremour. It would be a good practice to open and clear dust and use hot air from blower across terminals,AND, tighten them all once periodically, typically when we change smoke-alarm batteries