Domestic Wiring, Accessories and Installation Practice
Wiring systems and rules
Domestic work in Maharashtra follows IS 732 and the IE Rules. Common systems are cleat, casing-capping, batten and PVC conduit, surface or concealed. Concealed conduit is preferred in new construction because it protects cable and allows rewiring.
Accessories and colour code
- Phase: red, yellow, blue; neutral: black; earth: green or green-yellow.
- Lighting sub-circuit: 5 A; power sub-circuit: 15/16 A. A 30 mA RCCB is used for socket circuits.
- Switches must be in the phase conductor, never the neutral.
- A two-way switch has one common terminal and two strapper terminals; two such switches give staircase control.
- A 3-pin socket's earth pin is at the top and must connect to the earth wire, not to neutral.
Worked example
Staircase lighting: connect the phase to the common of switch A, run two strappers from A's L1/L2 to B's L1/L2, and take B's common to the lamp; the lamp's other terminal goes to neutral. Either switch then toggles the lamp because the strappers select one of two paths.
Traps
Looping the earth to neutral, using a 5 A switch on a 16 A load, and leaving bare copper exposed at terminals. A two-way circuit wired with the phase on the common of only one switch will not work as intended.