Is there any difference in these connections in home electrical wiring systems?

[lyo]

Hi All,

Is there any difference in these connections in home electrical wiring systems, whether it is for the hot line, the neutral line or the Earth line?

Twisting the wires together

Or Using busbar

Regards

 

[BradtheRad]

Electrically no difference. Millions of professional installations have wire ends twisted and secured with tape or wire-nuts.

Often the junction box is small and can barely contain a few wires. When you have a large distribution box is when there's room for bus bars and terminal blocks.

 

[betwixt]

Twisting wires together is VERY bad practice and potentially creates a fire risk. Imperfect contact and surface contamination of the wires causes resistance between them and as current flows it converts to heat (Ohms Law).

ALWAYS use a bus bar. The crimp connectors are best if you have the proper tools to fit them, otherwise clamping the cables with the bus bar screws is acceptable.

Check the electrical regulations for your country but I would be very surprised if the twisted connections were legal.

Brian.

 

[barry]

Twisting wires together/wire nuts are not bad practice; they are standard practice. There's no way you're going to fit a busbar inside a junction box.

 

[KlausST]

Hi,

It seems there is a difference between Europe and other regions.
I'm quite sure that twisting wires is not allowed here in Europe.

Klaus

 

[betwixt]

Agreeing with Klaus.
In Europe and the UK, not only is it illegal but there are regulations about the type of junction/fuse boxes as well. They all have bus bars and as of a few years ago also have to be of metal construction. I'm not sure about other countries but in the UK it is now illegal to install your own wiring or an extension of existing wiring (like fitting an extra light or socket) without it being tested and a certificate issued by a qualified electrician. The user, electrician and local authorities keep copies of the certificates and the installation has to be re-tested every ten years.

Brian.

 

[FvM]

You want to distinguish junction boxes and distribution boards (as shown in post #1 photos). Distribution boards are usually designed with room for bus bars, junction boxes are smaller.

The classical method to connect wires in junctions boxes uses screw terminals.

They are successively replaced by screwless terminals which are more reliable and can connect stranded wires without dedicated end sleeves.

The properties of these terminals are covered by several standards, e,g, IEC/EN 60998-x.

 

[barry]

Well, you learn something everyday.

The screw-terminal solution looks neat, but we’ve used wire nuts in the US for years. Also consider that we run 120 V vs. 230V.

 

[FvM]

A thread discussing wiring practice in different countries: https://diy.stackexchange.com/questions/10144/why-are-wire-nuts-not-used-in-the-uk

 

[betwixt]

I used to live in a newly built apartment in Palatine Illinois near Chicago. It amazed me that internal wiring in walls was inside metal conduit but as soon as it reached the switches/sockets it became a rats nest of twisted and taped joints. I understand that historically, because of the massive fire in the city, it was mandated that metal conduit was used but to my eyes as soon as the wires left the conduit they became dangerous. Being 120V instead of 230V may make contact with it slightly safer but it also doubles the current for a given load and that means more heat for a given resistance in the joints.

Brian.