2. Turn on and off the lights. An n-incoming line will have several poles when it seems to see the switch, and it will add several poles. For example, if a lamp is connected to a secondary switch, there are three wires between the lamp and the switch. That is, one incoming line, two outgoing lines and three outgoing lines.
3, one switch control light to another switch control light, L N PE three wires.
Extended data:
Composition structure
Electrical system diagram mainly includes electrical schematic diagram, electrical layout diagram, electrical installation wiring diagram, etc. Drawing software includes electrical CAD, protel99, Cadence, etc.
Therefore, the electrical schematic diagram is a kind of electrical system diagram. According to the working principle of the control line chart, the structure is simple and the levels are clear. It is mainly used to study and analyze the working principle of the circuit.
Electrical layout and installation drawings are mainly used to show the actual installation positions of various electrical equipment on mechanical equipment and electrical control cabinets. Provide necessary information for the manufacture, installation, maintenance and repair of mechanical and electrical control equipment.
The electrical installation wiring diagram provides detailed information about the electrical connection between various installation wiring diagram items, including the connection relationship of wiring devices, equipment or complete sets of equipment, cable types and laying lines.
Baidu Encyclopedia-Electrical Schematic Diagram