--- title: "Distribution substation site selection factors" subject: "Industrial Power Distribution and Illumination" chapter: 4 key: "semester_6/industrial_power_distribution_and_illumination:substation-site-location-factors" source: https://www.bctengineer.com/q/semester_6/industrial_power_distribution_and_illumination/substation-site-location-factors site: BCT Engineering --- # Distribution substation site selection factors Industrial Power Distribution and Illumination · Chapter 4: Distribution Substation of Industrial Plant - Asked in: 2078 Chaitra, 4 marks - Video: [Selection Of Site For Substation: EEBootCamp Knowledge in Minutes](https://www.youtube.com/watch?v=RDNsN-FmFxA) — EEB: Electrical Engineer BootCamp - Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14 - Page: https://www.bctengineer.com/q/semester_6/industrial_power_distribution_and_illumination/substation-site-location-factors - Whole chapter: https://www.bctengineer.com/md/semester_6/industrial_power_distribution_and_illumination/chapter-4 ## Question Define distribution substation for an industrial plant. What are the factors to be considered for the selection of location of site for the substation? ## Short answer An industrial distribution substation receives utility supply at11 kV and steps it down to400/230 V. Site selection factors: near load centre to minimise cable losses, proximity to HT supply, access, space, firm well-drained ground, safety from hazards, clean ventilated environment, cost and utility regulations. ## Answer A distribution substation of an industrial plant is the installation that receives power at 11 kV (or 33 kV) from the utility and, through transformers, switchgear and protection, supplies the plant at 400/230 V. #### Factors for selecting the substation site 1. **Load centre**: the site should be near the centre of gravity of the loads, found as x̄ = Σ(Pᵢ·xᵢ) / ΣPᵢ, ȳ = Σ(Pᵢ·yᵢ) / ΣPᵢ. This minimises LT cable length, voltage drop, losses and cost. 2. **Nearness to HT supply**: short route for the incoming 11 kV line or cable. 3. **Access**: approach road for bringing in the transformer and for maintenance and fire vehicles. 4. **Space**: room for the equipment, safety clearances, fencing and future extension. 5. **Ground and drainage**: firm, flood-free, well drained land with low soil resistivity for earthing. 6. **Safety**: away from fire hazards (fuel, chemicals, explosives), vibration and people movement. 7. **Environment**: clean, ventilated and dust-free; indoor type if the air is dusty or corrosive. 8. **Cost**: land cost and cost of cables and civil works. 9. **Utility rules**: approval of the supply authority and statutory clearances. ## Check yourself The answer's key points as multiple-choice questions, with the correct option and why. 1. What is a distribution substation of an industrial plant? A. A generator station for the plant B. A DC converter for drives C. Installation receiving 11 or 33 kV from the utility and supplying the plant at 400/230 V D. A battery room Answer: C. Transformers, switchgear and protection make up the substation. (Key point: Definition) 2. How is the load centre x-coordinate computed? A. x = sum(Pi xi) / sum(Pi) B. x = sum(xi) / sum(Pi) C. x = sum(Pi) / sum(xi) D. x = sum(Pi + xi) / n Answer: A. It is the load-weighted average position. (Key point: Load centre formula) 3. What is the benefit of placing the site at the load centre? A. Minimum 11 kV line length B. Maximum fault level C. Minimum LT cable length, voltage drop, losses and cost D. Least land cost always Answer: C. The load centre gives the least load x distance product. 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