Planning electrical installation of industrial building

Planning an industrial electrical installation means arranging supply, distribution, protection and wiring so that power reaches every machine safely, reliably and economically, with room for growth.

Fundamental considerations

1. Load assessment: list all machines, lighting, HVAC and utilities with ratings; estimate maximum demand using utilization (Ku) and simultaneity (Ks) factors.
2. Supply and substation: supply voltage (11 kV/400 V), transformer size and number, substation location at the load centre.
3. Distribution scheme: radial or ring; MDB and SDB locations near load groups; bus trunking for machine shops; separate lighting and power circuits.
4. Safety and protection: correct MCCB/MCB/fuse ratings, earth-fault protection (RCCB/ELCB), proper earthing, coordination and discrimination; compliance with codes (IEC/IS, NEA rules).
5. Cable selection and routing: size by current, voltage drop and short circuit; routes in trays/trenches away from heat and traffic.
6. Reliability and continuity: standby DG set, UPS for critical loads, duplicate feeders for essential processes.
7. Power quality and efficiency: power factor correction, harmonic control, efficient motors and lighting, metering for energy audit.
8. Environment: dusty, wet, corrosive or hazardous areas need suitable enclosures (IP rating) and flameproof equipment.
9. Flexibility and expansion: spare capacity (20–25 %) and spare ways in DBs.
10. Maintenance and economy: easy access to equipment, labelling, minimum initial plus running cost.