Junction from lengthy wire

[Sarvesaa]

Dear friends,

I am planning to put some wall sockets under my workbench I am routing 2.5 sqmm wire through casing pipe and I am planning to put 4 junction box on the table to power the instruments.
Each junction box will have 2 three pin sockets and 2 switches to on and off them.


I am a begineer in electrical stuff and I am only 17.
I want to know whether my way of junctioning is proper. Please give your advices on it.

The green wire will be going to junction box where sockets are present. Do consider the colour code this is just an example.
The thick red 2.5 sqmm wire is live.

[tautech]

STOP, leave mains wiring for someone that knows what they are doing as all you have done is make a death trap for some unfortunate soul that imagines the green wire to be mains ground !

[ebastler]

Regarding the wire colours, I am not sure whether you meant to say that we should ignore them, since you intend to use different (and hopefully correct!) colours in your wiring?

But there are other things wrong with your connection. You cannot simply twist the wires together for mains power, nor should you solder them -- both methods are unsafe. Use proper screw or spring-loaded clamp connectors; these will make a connection that is stable over time (does not oxidize) and at high temperatures. Also, such connectors will provide proper isolation to make the connection safe to touch.

Given your lack of experience, I can only second Tautech: Please don't do this yourself! Your installation could create electrical safety issues as well as fire hazards. Please get help from a qualified electrician for any work on mains wiring.

[pardo-bsso]

But there are other things wrong with your connection. You cannot simply twist the wires together for mains power, nor should you solder them -- both methods are unsafe.

As far as I know the local code here for residential installations does not mention solder as forbidden nor allowed.
Why is that a risk? (most of those installations here are done by twisting, works until you try to use a medium sized load a few years after, then all the lights flicker)

[ebastler]

I can't find an "official" source right now. But the first answers (by John E Wulff and Ken Wallewein) in this thread describe cautions against soldered mains connections which I have heard/read before:

https://www.quora.com/Why-is-soldering-not-allowed-or-common-for-home-wiring

[bdunham7]

I am a begineer in electrical stuff and I am only 17.
I want to know whether my way of junctioning is proper. Please give your advices on it.

What you are doing there would be almost workable if you properly soldered and taped it and the wires were clamped in place.  But it isn't a very good solution and I'd really recommend that you just get a power strip instead. 

https://www.amazon.in/GM-Modular-3060-Book-Multicolour/dp/B008XT42JU/ref=sr_1_3?crid=2IDEMNKK6J6U6&keywords=power+strip&qid=1660235690&sprefix=power+strip%2Caps%2C273&sr=8-3

[themadhippy]

some of these

and a wago221 box,job done

[bdunham7]

I can't find an "official" source right now. But the first answers (by John E Wulff and Ken Wallewein) in this thread describe cautions against soldered mains connections which I have heard/read before:

https://www.quora.com/Why-is-soldering-not-allowed-or-common-for-home-wiring

I've been using "unapproved" soldered connections, both repair and installation, for automotive and other applications for decades and have had zero failures.

Soldering used to the be approved method in the US for mains junctions and I think the main reason for abandoning that was simply speed and cost.  I don't think the failure rate was any higher than the non-zero failure rate of twisted and screw-clamped connections.  As for those replies, the first seems to be intermediate technobabble to me--yes you can screw up a solder connection, but that doesn't mean that they are inherently faulty.  And for the second, yes you will get fatigue failures if you have a lot of flexing going on anywhere in the region that the solder has wicked up the wire.  But that is totally avoidable with proper strain relief--which is usually required by either code or common sense in any case.

[pardo-bsso]

I can't find an "official" source right now. But the first answers (by John E Wulff and Ken Wallewein) in this thread describe cautions against soldered mains connections which I have heard/read before:

https://www.quora.com/Why-is-soldering-not-allowed-or-common-for-home-wiring

Alright, skipping the babble some of them make more sense in an environment subject to vibration or movements.

However, I've been soldering the fixed wiring in houses and local installations (say, in junction boxes) and that so far is trouble free since the last eight years or so. (to give more context, getting proper quality ferrules and associated terminal blocks or the like that would last is both hard and expensive)

Thanks for the link

[Someone]

But there are other things wrong with your connection. You cannot simply twist the wires together for mains power, nor should you solder them -- both methods are unsafe.

As far as I know the local code here for residential installations does not mention solder as forbidden nor allowed.
Why is that a risk?

Australian Standards are relatively good on this with a little bit of background/motivation included:
conductivity through joint =< cable conductivity
creep/stress
failure temperature

... and explicitly allow solder joints should they be of suitable design/quality.