Safety precautions in electrical works

Electricity can cause shock, burns and fire, so every stage of the electrification of a building must follow safety rules (Nepal Electricity Act / Regulations, NBC 207 and IS 732).

Safety precautions

• Earthing: connect all metal parts of appliances and the DB to earth (earth pit with a GI plate/pipe, resistance less than 5 ohm for buildings) to avoid shock.
• Protective devices: fuses, MCB, MCCB and ELCB/RCD (30 mA) to cut the supply on overload, short circuit and leakage; a lightning arrester on the roof.
• Proper materials: use standard-quality wires, switches and fittings of the correct current rating, and the proper conductor size for the load.
• Switch only the live (phase) wire: switches and fuses on the phase; neutral kept solid; use 3-pin plugs.
• Insulation and joints: all joints properly made and insulated; no bare wire; use junction boxes.
• Avoid overloading: do not connect many appliances to one socket; use separate circuits for heavy loads (AC, geyser).
• Safe location: keep wiring away from water pipes, gas lines and hot surfaces; place sockets and switches out of reach of children and away from bathrooms (or use waterproof types), at sufficient height.
• During work: switch off the main supply before repair; use insulated tools, rubber gloves and mats, and "danger/men at work" notices; avoid working in wet conditions; employ qualified electricians only.
• Fire precautions: keep extinguishers (CO2/dry powder) nearby; never use water on an electrical fire.
• Testing and maintenance: test insulation resistance (megger) and earth continuity after installation and periodically.