Wall chaser from angle grinder - video

[jdurand]

Inspected bare, then covered with 4 layers of insulating tapes per code. Then inspected and sealed into walls never to be seen again (unless you try hanging a picture right through the box).

[Frank S]

It also looks as though the wires are also welded at the ends before twisting

[jdurand]

yes, they are welded...or as they're copper, would that be brazed?

That's done AFTER the twist, it would be hard to twist them after you stuck the ends together.

I'm equating that joint to something like wire wrap, only there's no sharp edge to bite into the copper. I'm guessing they have to be cleaned before twisting.

BTW, anyone thinking of soldering them may be surprised to find a twist is a lower resistance and more durable junction than soldering. Sticking the ends together just makes it more so.

I don't know if only joints to be buried in plaster are done that way since there will never be an inspection of them again. It seems regular exposed joints are more lax since you can get at them to put out the fire.

[Frank S]

yes, they are welded...or as they're copper, would that be brazed?

That's done AFTER the twist, it would be hard to twist them after you stuck the ends together.

I'm equating that joint to something like wire wrap, only there's no sharp edge to bite into the copper. I'm guessing they have to be cleaned before twisting.

BTW, anyone thinking of soldering them may be surprised to find a twist is a lower resistance and more durable junction than soldering. Sticking the ends together just makes it more so.

I don't know if only joints to be buried in plaster are done that way since there will never be an inspection of them again. It seems regular exposed joints are more lax since you can get at them to put out the fire.

In Kuwait they have to use a conduit inside of the plaster walls but the black vinyl PVC 2mm thick is acceptable the box covers are left exposed but flush with the plaster. The German version of romex is the wiring used. Their reason for requiring piping is they figure sooner or later someone will overload as circuit and the wiring may have to be accessed for replacement Also in running a 20mm or larger conduit additional circuits can be added without the need to cut into the walls again except for where the branch circuits will be ran
I lived in a house that had 4 maids quarters of about 100 sq meters each 3 apartments of about 500 sq meters the main house which consisted of most of the basement the ground floor and the first floor about 1200 sq meters My apartment was on the 2nd floor it would be called the 3rd floor here in the USA plus we had a garden of sorts on the roof maybe 6 or 8 Date palms planted in huge concrete planters. each residence had their own breaker panel mine was located in the hallway next to one of the bedroom doors I converted that bedroom into a home work shop drilled a hole through the concrete wall into the back side of the panel and pulled a 30 amp 3 phase circuit through it giving me 3ph 415 V in my workshop then pulled a second circuit through the piping to each of the wall outlets so I could install a 15 amp 230 v outlet next to each of the 13 amp outlets.
The Kuwaiti who owned and lived in the main part of the house visited my apartment one night While I was showing him my micro machine shop in the converted bed room he marveled at all of the additional circuits I had installed. I told him that should we eventually leave that I would restore everything back to as it was before. he just said la,la,la,la, meaning no, no, no, no leave it as it is maybe another Amerike would want to lease the apartment. He spent a lot of time in my work shop learning to run the lathe and the mill as well as studying in my office reading books from my library.