Steel container below the fusebox?

[SUNRAY]

During my entire, long working life, I never, ever came across any joints, done by electricians, using solder, apart from large solder lugs, before the compression lugs came out.

I think I can say the same thing.
I the only one I recall, was one I did under the kitchen units in my daughters house, I assume it was the kitchen fitters left the open ring and the only way I could get to the cut but live cable was full stretch laying on my belly and doing the job by feel. Initially I attempted crimps but didn't have the access for the tool.

I repeat - I would be extremely wary of making any type of joint, in a normal run of trunking, filled with lots of other cables.

Sadly it's a very normal thing to find including where the wires have pulled from the choc bloc. As mentioned earlier it's something I've done a number of times for a temporary supply (which John seems to suggest it's not what the discussions about temporary were)

I don't have an issue with the OP's short bit of trunking, if it's purpose was one of containing lots of joints.

Indeed It would effectively be nothing more than a bespoke adaptable box and a method I've employed on a number of ocassions and not only for joints; this is 6 switches on 100x100mm, sorry about the terrible quality.

 

[Harry Bloomfield]

I the only one I recall, was one I did under the kitchen units in my daughters house, I assume it was the kitchen fitters left the open ring and the only way I could get to the cut but live cable was full stretch laying on my belly and doing the job by feel. Initially I attempted crimps but didn't have the access for the tool.

I recall one I did, it was a remote farmhouse conversion, the final day, when I was still at college, and a spur was needed from the ring, with no 30amp JB available. I suggested breaking into the ring, with a T-joint.

 

[JohnW2]

Actually I might have misled with my wording here. I consider twisted, soldered , sleeved permanent if done properly so should be as good as the conductor itself. Therefore if it is in trunking etc etc then I see no problem.

As you probably realise, that would probably be my view.

Choc blocks I consider temporary therefore not suitable.

Are you referring to any sort of 'screwed' connection, even if in a suitable 'enclosure with strain relief etc.?

Do we consider Wagos etc permanent or temporary? ... Personally, I am not totally convinced about them being much more than temporary in reality, maybe in time I will catch up with everyone else in this respect.

If they are enclosed (in a WagoBox) such as to qualify as 'MF', they may be installed in places that are 'inaccessble' for the entire remaining life of the building - so I imagine that would probably qualify as fairly 'permanent'. Enclosure in a WagoBox does not directly affect the quality of the connection, per se, so one might wonder whether Wagos used in any way w ere only suitable as 'temporary' (whatever that means!)

Systems that are classed as permanent should be inspected and tested every X years, i .... Parts of system intended as temporary should be inspected and tested more often.

There's always going to be debate/uncertainty about what 'temporary' and 'permanent' mean, even if there were attempts at arbitrary definitions - not the least because no-one has a crystal ball and given that (I presume) nothing in an electrical installation is every expected to last 'for ever'. In that sense, everything is, literally-speaking, 'temporary'.

 

[ebee]

Are you referring to any sort of 'screwed' connection, even if in a suitable 'enclosure with strain relief etc.?

Well screws can loosen over time and dependant on how tight/slack , yes strain relief should often be used, depending, and off course an enclosure of some type, be it a socket/switch/ junction box etc. should be able to be checked "easy-ish" depending upon your view of easy/difficult

 

[ebee]

Enclosure in a WagoBox does not directly affect the quality of the connection, per se, so one might wonder whether Wagos used in any way w ere only suitable as 'temporary' (whatever that means!)

My hesitance of faith in them does not make them unsuitable because I think it`s just my personal view

 

[JohnW2]

Well screws can loosen over time and dependant on how tight/slack , yes strain relief should often be used, depending, and off course an enclosure of some type, be it a socket/switch/ junction box etc. should be able to be checked "easy-ish" depending upon your view of easy/difficult

Yes, I understand and agree with all that. However, I was asking why you had specifically singled out 'choc blocks' and whether you were actually thinking about 'screwed connections' much more generally.

Kind Regards, John

 

[JohnW2]

My hesitance of faith in them does not make them unsuitable because I think it`s just my personal view

As you will know, you are not alone in your hesitation about 'sprung connections', as an alternative to the 'tried and tested over decades' screwed ones, even when accessible, let alone when not accessible for I&T.

It is almost certainly the case that they will prove fine in the long term, but I will no longer be around when enough decades of their widespread use has passed for us to be certain about their long term in-service performance.

I had similar 'concerns' when there was a massive shift from consumption of saturated fats (in dairy products) to polyunsaturated ones (mainly in sunflower oil). As with screwed electrical connections (particularly when 'inaccessible), there were good reasons for encourage people to reduce their consumption of saturated fat, but to encourage a massive increase in consumption of polyunsaturated ones was 'a step into the unknown' as far as possible long-term effects/consequences were concerned. Enough decades have now passed to reassure me that my concerns were unnecessary - but that wasn't inevitably going to be the case.

What I do find hard to understand is ... if 'we' feel that spring-based connections are so much better/reliable that only they should be allowed for 'inaccessible' joints, why are we (and manufacturers of accessories/devices/whatever) being encouraged to use the sprung connections for everything - even if they are 'accessible' (but with inspections usually being only 'every X years') ?

Kind Regards, John

 

[ebee]

What I do find hard to understand is ... if 'we' feel that spring-based connections are so much better/reliable that only they should be allowed for 'inaccessible' joints, why are we (and manufacturers of accessories/devices/whatever) being encouraged to use the sprung connections for everything - even if they are 'accessible' (but with inspections usually being only 'every X years') ?

Well, we all might have our own personal ideas on what is accessible or not. I suppose that if we put them in order of what we think of in terms of accessibility we would have many differing opinions on totally/mostly/fairly/reasonably then the or side un/not very/almost impossible etc etc etc we might even produce a classification as with the IP appendix etc and we would still fail to agree so we stick to is it or not. We each have our own viewpoint. Things that are very much could be one class (open to nearly all) and things that are less so to many (connections to switches and sockets, example) and things that are not (under floorboards, in lofts and away from a loft hatch) could give us just three basic states rather than just the two . But would that be helpful? Probably not in my opinion.
I think it possible that spring loaded are pretty good if operated by a lever and our manufacture might be improving over time and our classing which size or group of sizes fit which type of size and stranded/solid/flex multi strands. Probably better than my instinctive unease.

 

[Harry Bloomfield]

What I do find hard to understand is ... if 'we' feel that spring-based connections are so much better/reliable that only they should be allowed for 'inaccessible' joints, why are we (and manufacturers of accessories/devices/whatever) being encouraged to use the sprung connections for everything - even if they are 'accessible' (but with inspections usually being only 'every X years') ?

I'm not convinced that screw terminals are all that bad, or that the spring ones are all that reliable, assuming both are installed by competent hands. Screw terminals only fail, when they have given inadequate attention, when making the connections - not adequately tightened, each wire given a final tug test, for security.

The spring terminals, rely on the spring constantly apply the same amount of pressure, and the spring being able to take up any looseness which later appears. I don't know, though suspect, the area of contact with spring terminals is much less than that of screw versions, and the use a less conductive/higher resistance material, than the brass of higher current screw terminals.

 

[JohnW2]

Well, we all might have our own personal ideas on what is accessible or not. I suppose that if we put them in order of what we think of in terms of accessibility we would have many differing opinions on totally/mostly/fairly/reasonably then the or side un/not very/almost impossible etc etc etc we might even produce a classification as with the IP appendix etc and we would still fail to agree

I imagine that there would be a reasonable degree of agreement about the order in which which to put 'degrees of accessibility', but I certainly agree that it would be impossible to reach an agreement on where to draw the line as regards 'accessible'/'non-accessible' in a situation where regs were different for those two situations.

However, you have not addressed the question I posed 9and yiou quoted) ... IF 'we' have decided ('for better or for worse') that screwed terminals are 'not safe' to be used in 'non-accessible' locations (whatever we decide that means), but that at least some spring-loaded ones are, then why are 'we' not encouraging, or even 'requiring', electricians (and manufacturers of accessories/devices/whatever) to use spring-loaded terminals for 'everything'?

I think it possible that spring loaded are pretty good if operated by a lever ....and our manufacture might be improving over time and our classing which size or group of sizes fit which type of size and stranded/solid/flex multi strands. Probably better than my instinctive unease.

Yes, very probably true, but no absolute 'certainty'.

Personally, I certainly agree that I am more comfortable with lever-operated spring-loaded terminals than push-in ones.

Kind Regards, John

 

[JohnW2]

I'm not convinced that screw terminals are all that bad ...

Quite. On the contrary, I am convinced that they are not 'all that bad', having been in very widespread service for decades with very few problems (if they are used properly)

, or that the spring ones are all that reliable, assuming both are installed by competent hands.

Again, agreed. They probably are fine, but only a lot of time will totally confirm that. When one re-0invents a wheel, it's a very long time before one can be fairly certain that it is an improvement on (or even as good as) the previous one.

Screw terminals only fail, when they have given inadequate attention, when making the connections - not adequately tightened, each wire given a final tug test, for security.

In theory, 'thermal cycling' can loosen screwed connections, but I doubt that this is much of an issue in practice.

The spring terminals, rely on the spring constantly apply the same amount of pressure, and the spring being able to take up any looseness which later appears. I don't know, though suspect, the area of contact with spring terminals is much less than that of screw versions, and the use a less conductive/higher resistance material, than the brass of higher current screw terminals.

All agreed - together with the fact that, under certain conditions (again, including 'thermal' ones) springs can become less springy.

 

[ebee]

However, you have not addressed the question I posed 9and yiou quoted) ... IF 'we' have decided ('for better or for worse') that screwed terminals are 'not safe' to be used in 'non-accessible' locations (whatever we decide that means), but that at least some spring-loaded ones are, then why are 'we' not encouraging, or even 'requiring', electricians (and manufacturers of accessories/devices/whatever) to use spring-loaded terminals for 'everything'?

well I can go with encouraging on that one Soir.

 

[ebee]

In theory, 'thermal cycling' can loosen screwed connections, but I doubt that this is much of an issue in practice.

Yes I will go along with that one as well

 

[ebee]

I also suspect as Harry says "the area of contact with spring terminals is much less than that of screw versions, and the use a less conductive/higher resistance material, than the brass of higher current screw terminals." so perhaps yes to that one too

 

[JohnW2]

I also suspect as Harry says "the area of contact with spring terminals is much less than that of screw versions, and the use a less conductive/higher resistance material, than the brass of higher current screw terminals." so perhaps yes to that one too

Yes, I can't disagree with any of that.

As for the materials, I suppose it would be possible to plate a steel spring with copper or brass (or even gold!), which might improve things a bit.