Any time I have the switch beyond the light such that the white wire was the switched hot going back to the box with the light fixture, it gets marked at both ends with black heat shrink. When the white in three conductor cabling is acting as a traveler between three or four way switches and may be hot at times, it gets marked with red HS at the ends.
Back stab receptacles are tools of the devil.. Current code still allows them, but now only for 15A circuits and the holes permit the insertion of #14 wire only; they're too small for #12. Still won't use them that way. In fact, I do pigtails in receptacle boxes so the downstream circuitry is wire-nutted together rather than relying on sequential screw connections on all the upstream receptacles to pass the current. A bit of extra work, but more reliable in my opinion.
-Pat
US wiring is weird. Some things are very gung-ho, some things are so anal that you'd think NEC never went to the bathroom, ever.
In Sweden, almost all house wiring is in PVC conduit, which may be nailed to framing inside drywall clad walls, cast into concrete, or laid in chiseled cutouts made in masonry/expanded concrete walls which are then covered with mortar.
In conduit, one may pull insulated wires that are either single-wire (EK), 7-strand (FK) or more strands (MK or RK). Our "Romex" / "T&E" / "NYM-J", called EKK may these days be pulled in conduit too, which earlier was not allowed. EKK may also, which is another EU harmonisation, be hid behind mortar, which was not OK in the 80s. It is not allowed to run it inside drywall without conduit. The original installation method was nailing it to the wall using clips.
Areas start at 1,5mm
2 for a 10A circuit. Colour code is European harmonised,
Phase | Black or Brown |
Neutral | Blue |
Protective earth | Yellow/green |
Additionally, white tends to be used as a "lighting wire" which means going from the switch to the light, and denoting that the circuit is controlled. Old installs had red as PE, and I've got lots of green and yellow lighting wire in my conduit. All these colours are largely frowned upon today, not enough to mandate rewiring, but certainly to block new construction.
We had a period of wire nuts from about 1970 to 1990. They now are mostly obsolete, as are the "submarines", one-entry screw clamps.
Most joins are made with Wago 221's now.
Personally, I hate wire nuts, and love 221's. They are fantastic. And of course, a bit expensive. But worth it.
Marking is done, if at all, on the outlet/switch face, and indicates the fuse number and distribution board.