The better place to ask electrical questions:

https://www.theforumsa.co.za/forums/forumdisplay.php/31-Technology-Forum

It is never a good idea to join wires in the middle of nowhere. So keep connections and joints inside boxes and always tape them close. Any connection must replace the wire thickness so quality is paramount. Otherwise your connections will melt first when your current is too high for the wire size.

You need always to prepare to do faultfinding at some time in the future. So make it easy on yourself.

 Too many houses catch fire due to wiring shortcuts. The Bloem Havana building recently.

Alternative connectors:

https://www.livecopper.co.za/collections/cable-clips-ties-connectors?constraint=type_porcelain-connectors

https://www.livecopper.co.za/collections/crimps-terminals-sleeving/products/simple-solder-butt-connector-0-5-1-5mm

To get back to the original question.  Electricity (electrons) apparantly run on the outside surface of a wire so a multistrand cable can carry multiple "paths".  In a 220V circuit this is not crucial as the PD is high.  That is why multistrand is generally used for DC cables as they are generally of a lower PD and your losses are therefore minimised.

And just to stir the pot.  "Screwits" are brilliant to work with, but I hate them as I find if there is any vibration, they do work loose.  A solution is to wrap them with insulation tape, but that in itself becomes a pain as it gets all sticky and crap to work with thereafter.  Not insulting anyone, just my experience working on fuel bowsers

On 2018/12/08 at 9:05 PM, dax021 said:

To get back to the original question.  Electricity (electrons) apparantly run on the outside surface of a wire so a multistrand cable can carry multiple "paths".  In a 220V circuit this is not crucial as the PD is high.  That is why multistrand is generally used for DC cables as they are generally of a lower PD and your losses are therefore minimised.

And just to stir the pot.  "Screwits" are brilliant to work with, but I hate them as I find if there is any vibration, they do work loose.  A solution is to wrap them with insulation tape, but that in itself becomes a pain as it gets all sticky and crap to work with thereafter.  Not insulting anyone, just my experience working on fuel bowsers

Yes that was my experience as well. Others may have difference experience though but I prefer more permanent and better protected connections.

On 2018/12/08 at 9:05 PM, dax021 said:

Electricity (electrons) apparantly run on the outside surface of a wire

It's called Skin Effect and it only happens with AC current, and at 50Hz the effect is so small that for all practical purposes it doesn't apply, at least not at residential wiring level. At higher frequencies it does play a role, so it's more of a concern when you're doing DC/DC converters and you have to decide the design of the inductor component.

 

A few "rules" passed on to me by an old style electrician.

(1) Use multistrand cable in conduits because of flexibility and ease of drawing in wires.

(2) Surfix is quite brittle and stiff to work with in small boxes, so avoid if at all possible.

(3) Use the correct gauge according to regulations. 1.5 mm for lights, 2.5 mm minimum for wall sockets, 4 mm for stoves hobs, geysers.

(4) Avoid ALL hidden connections. Hence why the standard is to diasy chain because all connection points are easy to reach.

(5) "Never" join cables and then hid the joints ---- they must be in boxes where they can be accesed if necessary. and use crimpee ferrules and insulated for "straight" joints. AND please use a proper crimping tool NOT a pliers!

(6) Avoid connection strips if you are able to --- use screwits of the correct size for the cables. I personally hate both types.

(7) If you do use connection strips - get good quality that are the correct size for the cable and current rating.

 

 

Edited February 14, 20197 yr by Geoff.D

9 hours ago, Geoff.D said:

A few "rules" passed on to me by an old style electrician.

(1) Use multistrand cable in conduits because of flexibility and ease of drawing in wires.

(2) Surfix is quite brittle and stiff to work with in small boxes, so avoid if at all possible.

(3) Use the correct gauge according to regulations. 1.5 mm for lights, 2.5 mm minimum for wall sockets, 4 mm for stoves hobs, geysers.

(4) Avoid ALL hidden connections. Hence why the standard is to diasy chain because all connection points are easy to reach.

(5) "Never" join cables and then hid the joints ---- they must be in boxes where they can be accesed if necessary. and use crimpee ferrules and insulated for "straight" joints. AND please use a proper crimping tool NOT a pliers!

(6) Avoid connection strips if you are able to --- use screwits of the correct size for the cables. I personally hate both types.

(7) If you do use connection strips - get good quality that are the correct size for the cable and current rating.

 

 

I would rather rerun a whole new cable, than join a cable in the roof or even in the open. Adding "joints" of any kind tend to be problematic over time.