Installing and insulating electrical conductors
Branching electrical conductors is done to add a new consumer to the network. Household appliances are connected to the mains through a socket. Order of work (only with the power off, by a specialist): insulation is removed with the stripping knife from a 30 mm part of the main wire and the 50 mm end of the wire to be joined; wire ends are cleaned until bright; the wires are laid perpendicular to one another and wound 4–5 turns; the extra end is cut with side cutters and pressed with flat pliers; the joint is soldered; starting 10–15 mm beyond the junction, insulating tape is wrapped twice, and the junction is wrapped two or three times. Only then is the insulation reliable. In modern homes wires are now usually joined with special connectors (terminal blocks) or in junction boxes rather than by twisting. A soldering iron is a very hot tool: only adults work with it.
Important: children never work with mains (socket) voltage. In this lesson: only looking, pictures and small battery models (up to 4.5 V); cutting, stripping, soldering or connecting real wires is done only by the teacher/electrician with the power off. Activity: draw a card “branching” diagram (pencils, coloured lines): main wire, branch, 30 mm and 50 mm marks.