I've been using loads of Wago connectors recently, including a couple of maintenance-free locations, and it got me wondering why the wire connections on the backs of sockets etc aren't using this sort of technology? Screw terminals seem rather poor in comparison with a number of issues that could be improved upon with spring connectors. What am I missing as to why this hasn't happened?

On Tuesday, 14 July 2020 12:53:35 UTC+1, Mathew Newton wrote:
I've been using loads of Wago connectors recently, including a couple of maintenance-free locations, and it got me wondering why the wire connections on the backs of sockets etc aren't using this sort of technology? Screw terminals seem rather poor in comparison with a number of issues that could be improved upon with spring connectors. What am I missing as to why this hasn't happened?

Probably because each terminal on a socket is designed to accept at least three 2.5mm2 wires whereas each terminal on a Wago accepts a single cable. In view of this I think it is matter of space available to provide enough spring loaded terminals to achieve the same.

Richard

In article ,
Mathew Newton wrote:
I've been using loads of Wago connectors recently, including a couple of
maintenance-free locations, and it got me wondering why the wire
connections on the backs of sockets etc aren't using this sort of
technology? Screw terminals seem rather poor in comparison with a number
of issues that could be improved upon with spring connectors. What am I
missing as to why this hasn't happened?


What makes you think a spring is going to provide a better connection than
a screw? It would have to be a *very* powerful spring to get even near the
same pressure.

--
*I can see your point, but I still think you're full of ****.

Dave Plowman London SW
To e-mail, change noise into sound.

On 14/07/2020 13:11, Tricky Dicky wrote:
On Tuesday, 14 July 2020 12:53:35 UTC+1, Mathew Newton wrote:
I've been using loads of Wago connectors recently, including a couple of maintenance-free locations, and it got me wondering why the wire connections on the backs of sockets etc aren't using this sort of technology? Screw terminals seem rather poor in comparison with a number of issues that could be improved upon with spring connectors. What am I missing as to why this hasn't happened?

Probably because each terminal on a socket is designed to accept at least three 2.5mm2 wires...

or 2 x 4mm so the connectors would have to cope with a wide range of
solid and stranded


--
Robin
reply-to address is (intended to be) valid

On 14/07/2020 13:57:16, Dave Plowman (News) wrote:
In article ,
Mathew Newton wrote:
I've been using loads of Wago connectors recently, including a couple of
maintenance-free locations, and it got me wondering why the wire
connections on the backs of sockets etc aren't using this sort of
technology? Screw terminals seem rather poor in comparison with a number
of issues that could be improved upon with spring connectors. What am I
missing as to why this hasn't happened?


What makes you think a spring is going to provide a better connection than
a screw? It would have to be a *very* powerful spring to get even near the
same pressure.

Given you can use these spring type connectors in inaccessible places
does suggest they are more reliable long term.

One thing about a spring is it can take up movement which will be caused
by continual temperature cycling and consequential thermal expansion and
contraction.

I have come across screws that need to be tightened on shower
connections and their associated ceiling switches. In fact if you use
aluminium cable the IET regs says you need to service the screw
connections on a regular basis.

Otherwise, I agree it does feel counter-intuitive.

Dave Plowman wrote:

What makes you think a spring is going to provide a better connection than
a screw? It would have to be a *very* powerful spring to get even near the
same pressure.

Have you looked inside a wago connector?

On 14/07/2020 12:53, Mathew Newton wrote:
I've been using loads of Wago connectors recently, including a couple
of maintenance-free locations, and it got me wondering why the wire
connections on the backs of sockets etc aren't using this sort of
technology? Screw terminals seem rather poor in comparison with a
number of issues that could be improved upon with spring connectors.
What am I missing as to why this hasn't happened?

Inertia - i.e. its always been done that way, and perhaps cost.

(BS1363-2 does have quite extensive chapter and verse on use of
screwless terminals - so the standards do support the use of them (at
least of 2016 - II have not checked earlier versions)

On a practical level they would need to be the leaver type rather than
just "push in" to allow for easy dismounting of wires when doing
inspection and test.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On 14/07/2020 14:20:04, Andy Burns wrote:
Dave Plowman wrote:

What makes you think a spring is going to provide a better connection
than
a screw? It would have to be a *very* powerful spring to get even near
the
same pressure.

Have you looked inside a wago connector?

I have and wondered about the limited contact area between the spring
and cable.

On Tuesday, 14 July 2020 13:57:29 UTC+1, Dave Plowman (News) wrote:

What makes you think a spring is going to provide a better connection than
a screw? It would have to be a *very* powerful spring to get even near the
same pressure.

It was the prevalence of such connectors being used in junction boxes, light fittings etc and the fact that they can be used in maintenance-free situations unlike screw terminals that gave me the though and properties such as foolproof method of connection (no torque issues to consider) and low (zero?) risk of the connection coming loose that appealed.

In case you are not familiar, this is the sort of thing I was thinking of:

https://www.wago.com/gb/installation...ctor/p/221-412

Regarding pressure, either the spring does in fact apply the similar pressure as a screw or (more likely) it provides sufficient pressure for electrical contact and relies on mechanical barbing to prevent pullout.

Whilst anecdotal and subject to sample size bias, but I often hear/read about loose screw terminals but have never hear of Wago failures.

On Tuesday, 14 July 2020 13:11:19 UTC+1, Tricky Dicky wrote:

Probably because each terminal on a socket is designed to accept at least three 2.5mm2 wires whereas each terminal on a Wago accepts a single cable. In view of this I think it is matter of space available to provide enough spring loaded terminals to achieve the same.

Yes, that'd have to be a consideration but there is a lot of space within the internals of a socket and looking at the size of a Wago 221 - particularly the innards - they're not exactly bulky.

I see the need for one-cable-per-terminal to actually be an advantage as it'd avoid the potential issue that arise from compressing multiple cables in a screw terminal e.g. variation of contact pressure if sitting side-by-side etc.

On Tuesday, 14 July 2020 14:00:11 UTC+1, Robin wrote:

or 2 x 4mm so the connectors would have to cope with a wide range of
solid and stranded

Yes, but I guess that's where the inherent properties of a spring loaded terminal makes it a non-issue as they usually do accept a wide range of cable types.

On Tuesday, 14 July 2020 15:28:49 UTC+1, John Rumm wrote:

Inertia - i.e. its always been done that way, and perhaps cost.

...and judging by the responses received not everyone (i.e. no one!) is convinced as I am. Maybe it's one for Dragon's Den... ;-)

On a practical level they would need to be the leaver type rather than
just "push in" to allow for easy dismounting of wires when doing
inspection and test.

Yes, and I must admit to preferring the lever type anyway - far easier to use even for a wire connector where twisting to remove isn't so much of an issue.

Have you ever encountered sprung connections on the back of speakers? Crap
connections.
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.!
"Mathew Newton" wrote in message
...
I've been using loads of Wago connectors recently, including a couple of
maintenance-free locations, and it got me wondering why the wire connections
on the backs of sockets etc aren't using this sort of technology? Screw
terminals seem rather poor in comparison with a number of issues that could
be improved upon with spring connectors. What am I missing as to why this
hasn't happened?

Brian Gaff wrote:

Have you ever encountered sprung connections on the back of speakers?

different animals, I'd send you a picture, but ...

Yes, but they're not the sort of thing I had in mind. Wago, and other manufacturers, make screwless wire connectors which can be more regarded as spring loaded 'clamps' which, whilst similar in function to a speaker connector, are designed and implemented to be suitable for high current mains voltage connections.

On Tuesday, 14 July 2020 20:32:05 UTC+1, Brian Gaff (Sofa) wrote:
Have you ever encountered sprung connections on the back of speakers? Crap
connections.
Brian

On Tuesday, 14 July 2020 19:50:51 UTC+1, Mathew Newton wrote:
On Tuesday, 14 July 2020 13:57:29 UTC+1, Dave Plowman (News) wrote:

What makes you think a spring is going to provide a better connection than
a screw? It would have to be a *very* powerful spring to get even near the
same pressure.

It was the prevalence of such connectors being used in junction boxes, light fittings etc and the fact that they can be used in maintenance-free situations unlike screw terminals that gave me the though and properties such as foolproof method of connection (no torque issues to consider) and low (zero?) risk of the connection coming loose that appealed.

if only.

In case you are not familiar, this is the sort of thing I was thinking of:

https://www.wago.com/gb/installation...ctor/p/221-412

Regarding pressure, either the spring does in fact apply the similar pressure as a screw

no chance. none.

or (more likely) it provides sufficient pressure for electrical contact and relies on mechanical barbing to prevent pullout.

connections also need to be gastight.

Whilst anecdotal and subject to sample size bias, but I often hear/read about loose screw terminals but have never hear of Wago failures.

There are many million screw connectors in use, far fewer spring connectors.. Springs are widely used in US sockets and are notorious for high resistance failures.

I don't know why no-one uses spot welding.


NT

On Tuesday, 14 July 2020 19:58:44 UTC+1, Mathew Newton wrote:
On Tuesday, 14 July 2020 15:28:49 UTC+1, John Rumm wrote:

Inertia - i.e. its always been done that way, and perhaps cost.

..and judging by the responses received not everyone (i.e. no one!) is convinced as I am. Maybe it's one for Dragon's Den... ;-)

you don't have a patent on them

On a practical level they would need to be the leaver type rather than
just "push in" to allow for easy dismounting of wires when doing
inspection and test.

Yes, and I must admit to preferring the lever type anyway - far easier to use even for a wire connector where twisting to remove isn't so much of an issue.

easier if the wire's straight and clean. But reliable? not especially.


NT

On Tuesday, 14 July 2020 13:11:19 UTC+1, Tricky Dicky wrote:
On Tuesday, 14 July 2020 12:53:35 UTC+1, Mathew Newton wrote:
I've been using loads of Wago connectors recently, including a couple of maintenance-free locations, and it got me wondering why the wire connections on the backs of sockets etc aren't using this sort of technology? Screw terminals seem rather poor in comparison with a number of issues that could be improved upon with spring connectors. What am I missing as to why this hasn't happened?

Probably because each terminal on a socket is designed to accept at least three 2.5mm2 wires whereas each terminal on a Wago accepts a single cable. In view of this I think it is matter of space available to provide enough spring loaded terminals to achieve the same.

Richard

It has always seemed wrong to stuff multiple wires into one terminal.

I know there would be issues, but I have always wanted one terminal per wire.

On Tuesday, 14 July 2020 22:24:50 UTC+1, wrote:
I don't know why no-one uses spot welding.

Never seen a Proteus MCB? ;-)

Owain

On 14/07/2020 12:53, Mathew Newton wrote:
I've been using loads of Wago connectors recently, including a couple of maintenance-free locations, and it got me wondering why the wire connections on the backs of sockets etc aren't using this sort of technology? Screw terminals seem rather poor in comparison with a number of issues that could be improved upon with spring connectors. What am I missing as to why this hasn't happened?

Somewhat off topic but....
They had them on some striplights battens I bought recently, pain in the
arse when using flex.

In article ,
Mathew Newton wrote:
What makes you think a spring is going to provide a better connection than
a screw? It would have to be a *very* powerful spring to get even near the
same pressure.

It was the prevalence of such connectors being used in junction boxes,
light fittings etc and the fact that they can be used in
maintenance-free situations unlike screw terminals that gave me the
though and properties such as foolproof method of connection (no torque
issues to consider) and low (zero?) risk of the connection coming loose
that appealed.

If you don't possess simple tools like a suitable screwdriver, how are you
going to access that light fitting? Or JB, come to that?

I've never had a problem with a screw connection coming loose. Although I
have seen it on so called pro installations.

If you really don't know how to tighten a screw, you'd likely best not
fiddle with mains electrics either.

--
*Elephants are the only mammals that can't jump *

Dave Plowman London SW
To e-mail, change noise into sound.

On Wednesday, 15 July 2020 14:00:56 UTC+1, Dave Plowman (News) wrote:

If you don't possess simple tools like a suitable screwdriver, how are you
going to access that light fitting? Or JB, come to that?

I've never had a problem with a screw connection coming loose. Although I
have seen it on so called pro installations.

If you really don't know how to tighten a screw, you'd likely best not
fiddle with mains electrics either.

Thanks Dave; always appreciate your cheery input! ;-)

On Wednesday, 15 July 2020 15:27:51 UTC+1, Mathew Newton wrote:
On Wednesday, 15 July 2020 14:00:56 UTC+1, Dave Plowman (News) wrote:

If you don't possess simple tools like a suitable screwdriver, how are you
going to access that light fitting? Or JB, come to that?

I've never had a problem with a screw connection coming loose. Although I
have seen it on so called pro installations.

If you really don't know how to tighten a screw, you'd likely best not
fiddle with mains electrics either.

Thanks Dave; always appreciate your cheery input! ;-)

the rest of us have all come across loose screws. I bet Dave has one somewhere.

In article ,
wrote:
On Wednesday, 15 July 2020 15:27:51 UTC+1, Mathew Newton wrote:
On Wednesday, 15 July 2020 14:00:56 UTC+1, Dave Plowman (News) wrote:

If you don't possess simple tools like a suitable screwdriver, how
are you going to access that light fitting? Or JB, come to that?

I've never had a problem with a screw connection coming loose.
Although I have seen it on so called pro installations.

If you really don't know how to tighten a screw, you'd likely best not
fiddle with mains electrics either.

Thanks Dave; always appreciate your cheery input! ;-)

the rest of us have all come across loose screws. I bet Dave has one somewhere.


Yes I have. I've a feeling some cowboys do just this to get future work.
But not on any of my own work.

If spring connections were the ideal, why not on your riser and meter, etc?

--
*A computer once beat me at chess, but it was no match for me at kickboxing.

Dave Plowman London SW
To e-mail, change noise into sound.

Dave Plowman wrote:

If spring connections were the ideal, why not on your riser and meter, etc?

Wago do connectors that far exceed 25 mm^2 meter tails

https://www.wago.com/gb/electrical-interconnections/discover-rail-mount-terminal-blocks/high-current-terminal-blocks

Andy Burns wrote:

https://www.wago.com/gb/electrical-interconnections/discover-rail-mount-terminal-blocks/high-current-terminal-blocks

Actually those are screw//cage clamp, not spring terminals ...

In article ,
Andy Burns wrote:
Dave Plowman wrote:

If spring connections were the ideal, why not on your riser and meter, etc?

Wago do connectors that far exceed 25 mm^2 meter tails

https://www.wago.com/gb/electrical-interconnections/discover-rail-mount-terminal-blocks/high-current-terminal-blocks

I can see the benefit for speedy assembly. But can't for the life of me
see why it would give a better connection than a properly tightened screw.
But do understand many seem incapable of doing this.

--
*Never underestimate the power of stupid people in large groups

Dave Plowman London SW
To e-mail, change noise into sound.

Dave Plowman (News) wrote:

I can see the benefit for speedy assembly. But can't for the life of me
see why it would give a better connection than a properly tightened screw.
But do understand many seem incapable of doing this.

Copper under screw terminals seems to need (Infrequent) tightening to
remain a good connection; a spring terminal will take up the "slack"
automatically ...

On Thursday, 16 July 2020 15:08:33 UTC+1, Dave Plowman (News) wrote:

If spring connections were the ideal, why not on your riser and meter, etc?

Funny you should say that as I was also wondering about their use on MCBs/RCDs too...

When Adam fitted a new circuit for me he gave everything a once over and found one MCB screw whose thread wouldn't tighten enough. Whether the thread had been stripped from being overtightened or had never been right I don't know, but I remember thinking what a poor invention the screw was and how it'll never take off. ;-)

Incidentally, I'm not suggesting spring connectors are the ideal - more just wondering what the benefits and drawbacks over screw terminals might be in applications that we don't currently see them.

On Thursday, 16 July 2020 22:01:19 UTC+1, Mathew Newton wrote:
On Thursday, 16 July 2020 15:08:33 UTC+1, Dave Plowman (News) wrote:

If spring connections were the ideal, why not on your riser and meter, etc?

Funny you should say that as I was also wondering about their use on MCBs/RCDs too...

When Adam fitted a new circuit for me he gave everything a once over and found one MCB screw whose thread wouldn't tighten enough. Whether the thread had been stripped from being overtightened or had never been right I don't know, but I remember thinking what a poor invention the screw was and how it'll never take off. ;-)

Incidentally, I'm not suggesting spring connectors are the ideal - more just wondering what the benefits and drawbacks over screw terminals might be in applications that we don't currently see them.

worse reliability


NT

In article ,
Andy Burns wrote:
Dave Plowman (News) wrote:

I can see the benefit for speedy assembly. But can't for the life of me
see why it would give a better connection than a properly tightened screw.
But do understand many seem incapable of doing this.

Copper under screw terminals seems to need (Infrequent) tightening to
remain a good connection; a spring terminal will take up the "slack"
automatically ...


I rewired this house when I bought it. Over 40 years ago. I've not had a
problem with any terminal screws coming loose. Despite it having a much
more complicated electrical system than most.

--
*There are 3 kinds of people: those who can count & those who can't.

Dave Plowman London SW
To e-mail, change noise into sound.

Dave Plowman wrote:

I've not had a problem with any terminal screws coming loose.

Do you know because

a) you've checked them, or

b) it hasn't caught fire so far :-)

On 17/07/2020 11:19, Dave Plowman (News) wrote:
In article ,
Andy Burns wrote:
Dave Plowman (News) wrote:

I can see the benefit for speedy assembly. But can't for the life of me
see why it would give a better connection than a properly tightened screw.
But do understand many seem incapable of doing this.

Copper under screw terminals seems to need (Infrequent) tightening to
remain a good connection; a spring terminal will take up the "slack"
automatically ...


I rewired this house when I bought it. Over 40 years ago. I've not had a
problem with any terminal screws coming loose. Despite it having a much
more complicated electrical system than most.


Your sample of one, while welcome, wd be more useful if accompanied by
information about e.g. occupancy (number, ages and activities - eg heavy
metal fans? ) and nearby traffic (volume? buses? HGVs?).

--
Robin
reply-to address is (intended to be) valid

In article ,
Andy Burns wrote:

Dave Plowman wrote:

I've not had a problem with any terminal screws coming loose.

Do you know because

a) you've checked them, or

b) it hasn't caught fire so far :-)

I've repaired plenty of pro installations where the problem was caused by
loose screws. Not seen a fire due to this - that's why you use a backbox.

Usual symptoms are socket(s) etc just stopping working.

--
*A closed mouth gathers no feet.*

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
Robin wrote:
On 17/07/2020 11:19, Dave Plowman (News) wrote:
In article ,
Andy Burns wrote:
Dave Plowman (News) wrote:

I can see the benefit for speedy assembly. But can't for the life of me
see why it would give a better connection than a properly tightened screw.
But do understand many seem incapable of doing this.

Copper under screw terminals seems to need (Infrequent) tightening to
remain a good connection; a spring terminal will take up the "slack"
automatically ...


I rewired this house when I bought it. Over 40 years ago. I've not had a
problem with any terminal screws coming loose. Despite it having a much
more complicated electrical system than most.


Your sample of one, while welcome, wd be more useful if accompanied by
information about e.g. occupancy (number, ages and activities - eg heavy
metal fans? ) and nearby traffic (volume? buses? HGVs?).

I mention it as one example. I've wired loads of houses in the past, and
never had a call back due to loose screws.

Now tell us your experience of how you can't tighten a screw properly so
need something easier?

--
*In "Casablanca", Humphrey Bogart never said "Play it again, Sam" *

Dave Plowman London SW
To e-mail, change noise into sound.

On Friday, 17 July 2020 11:34:05 UTC+1, Andy Burns wrote:
Dave Plowman wrote:

I've not had a problem with any terminal screws coming loose.

Do you know because

a) you've checked them, or

b) it hasn't caught fire so far :-)

his posts indicate he has had a problem with at least one screw coming loose. Probably not electrical or terminal though.

On 17/07/2020 12:54:37, Robin wrote:
On 17/07/2020 11:19, Dave Plowman (News) wrote:
In article ,
Â*Â*Â* Andy Burns wrote:
Dave Plowman (News) wrote:

I can see the benefit for speedy assembly. But can't for the life of me
see why it would give a better connection than a properly tightened
screw.
But do understand many seem incapable of doing this.

Copper under screw terminals seems to need (Infrequent) tightening to
remain a good connection; a spring terminal will take up the "slack"
automatically ...


I rewired this house when I bought it. Over 40 years ago. I've not had a
problem with any terminal screws coming loose. Despite it having a much
more complicated electrical system than most.


Your sample of one, while welcome, wd be more useful if accompanied by
information about e.g. occupancy (number, ages and activities - eg heavy
metal fans? ) and nearby traffic (volume? buses? HGVs?).

As someone who has replaced two ceiling shower switches where the
plastic was showing signs of darkening, I would say Dave has been
extremely fortunate.

In article ,
Dave Plowman (News) wrote:
In article ,
Andy Burns wrote:

Dave Plowman wrote:

I've not had a problem with any terminal screws coming loose.

Do you know because

a) you've checked them, or

b) it hasn't caught fire so far :-)

I've repaired plenty of pro installations where the problem was caused by
loose screws. Not seen a fire due to this - that's why you use a backbox.

Usual symptoms are socket(s) etc just stopping working.

but when you're in a timber barn and a surface socket is too hot to touch?

--
from KT24 in Surrey, England
"I'd rather die of exhaustion than die of boredom" Thomas Carlyle

On 17/07/2020 15:17:11, Dave Plowman (News) wrote:
In article ,
Robin wrote:
On 17/07/2020 11:19, Dave Plowman (News) wrote:
In article ,
Andy Burns wrote:
Dave Plowman (News) wrote:

I can see the benefit for speedy assembly. But can't for the life of me
see why it would give a better connection than a properly tightened screw.
But do understand many seem incapable of doing this.

Copper under screw terminals seems to need (Infrequent) tightening to
remain a good connection; a spring terminal will take up the "slack"
automatically ...


I rewired this house when I bought it. Over 40 years ago. I've not had a
problem with any terminal screws coming loose. Despite it having a much
more complicated electrical system than most.


Your sample of one, while welcome, wd be more useful if accompanied by
information about e.g. occupancy (number, ages and activities - eg heavy
metal fans? ) and nearby traffic (volume? buses? HGVs?).

I mention it as one example. I've wired loads of houses in the past, and
never had a call back due to loose screws.

Sometimes it can take years for a screw connection to become loose.

Now tell us your experience of how you can't tighten a screw properly so
need something easier?

This is not about tightening screws, it is about thermal cycling and a
joint becoming loose. One example publication:

https://www.newark.com/wcsstore/Exte...onnections.pdf

In your line you must have heard of dry joints, would you say that is
the fault of the person doing the soldering (or the machine in terms of
flow soldering or similar) or a feature of thermally induced fractures?

"Fredxx" wrote in message
...
On 17/07/2020 15:17:11, Dave Plowman (News) wrote:
In article ,
Robin wrote:
On 17/07/2020 11:19, Dave Plowman (News) wrote:
In article ,
Andy Burns wrote:
Dave Plowman (News) wrote:

I can see the benefit for speedy assembly. But can't for the life of
me
see why it would give a better connection than a properly tightened
screw.
But do understand many seem incapable of doing this.

Copper under screw terminals seems to need (Infrequent) tightening to
remain a good connection; a spring terminal will take up the "slack"
automatically ...


I rewired this house when I bought it. Over 40 years ago. I've not had
a
problem with any terminal screws coming loose. Despite it having a much
more complicated electrical system than most.


Your sample of one, while welcome, wd be more useful if accompanied by
information about e.g. occupancy (number, ages and activities - eg heavy
metal fans? ) and nearby traffic (volume? buses? HGVs?).

I mention it as one example. I've wired loads of houses in the past, and
never had a call back due to loose screws.

Sometimes it can take years for a screw connection to become loose.

Now tell us your experience of how you can't tighten a screw properly so
need something easier?

This is not about tightening screws, it is about thermal cycling and a
joint becoming loose. One example publication:

https://www.newark.com/wcsstore/Exte...onnections.pdf

In your line you must have heard of dry joints, would you say that is the
fault of the person doing the soldering

It certainly can be.

(or the machine in terms of flow soldering or similar)

Not usually.

or a feature of thermally induced fractures?

Yes it can be.