--- title: "Classification of electrical consumers and demand" subject: "Utilization of Electrical Energy" chapter: 1 key: "semester_7/utilization_of_electrical_energy:classification-consumers-demand" source: https://www.bctengineer.com/q/semester_7/utilization_of_electrical_energy/classification-consumers-demand site: BCT Engineering --- # Classification of electrical consumers and demand Utilization of Electrical Energy · Chapter 1: Introduction - Asked in: 2070 Chaitra - Video: [Electricity consumer categories | Types of loads](https://www.youtube.com/watch?v=PGHjO0XIHyo) — Salaar Khan - Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14 - Page: https://www.bctengineer.com/q/semester_7/utilization_of_electrical_energy/classification-consumers-demand - Whole chapter: https://www.bctengineer.com/md/semester_7/utilization_of_electrical_energy/chapter-1 ## Question Explain the classification of electrical consumers and their demand. ## Short answer Consumers are classified as domestic, commercial, industrial, agricultural, street lighting, and public utilities. Domestic loads are small, peak in evening, with low load factor; industrial loads are large, steady, with high load factor. Agricultural demand is seasonal, and different peak times give a diversity factor above one. ## Answer Electrical consumers are classified according to the purpose of use, size of load and supply voltage. Each class has a typical demand pattern, load factor and peak time, which the utility uses for planning and tariff setting. #### Classes of consumers **1. Domestic (residential)** - Loads: lights, fans, TV, refrigerator, water heater, cooker, iron, pumps. - Demand: small (about 0.5 to 10 kW); 230 V single-phase or 400 V three-phase. - Peak in the evening; low load factor (about 10 to 20 %); high diversity among households. **2. Commercial** - Shops, offices, hotels, restaurants, hospitals, cinemas, banks. - Loads: lighting, air-conditioning, lifts, computers. - Demand: medium; peak during business hours; load factor about 25 to 40 %; 400 V or 11 kV. **3. Industrial** - Small-scale (up to about 50 kW, 400 V), medium-scale (about 50 to 1000 kW, 11 kV), large-scale (above about 1 MW, 33 kV and above). - Loads: motors, furnaces, welding, electrolysis, lighting. - Demand: large and steady; high load factor (60 to 80 % for multi-shift plants); needs reactive power, so power-factor correction. **4. Agricultural (irrigation)** - Pumps, threshers, mills. Seasonal, mostly daytime; low load factor (about 15 to 25 %). **5. Street lighting** - Fixed night-time load (dusk to dawn); load factor about 40 to 50 %; predictable. **6. Public utilities and others** - Water supply and sewage pumping (fairly continuous), traction and EV charging (fluctuating), temples, community, government institutions, bulk supply. #### Comparison of demand | Class | Size | Voltage | Load factor | Peak | |---|---|---|---|---| | Domestic | Small | 230/400 V | 10-20 % | Evening | | Commercial | Medium | 400 V/11 kV | 25-40 % | Day | | Industrial | Large | 400 V-132 kV | 60-80 % | Day/continuous | | Agricultural | Medium | 400 V/11 kV | 15-25 % | Dry season | | Street light | Small | 230/400 V | 40-50 % | Night | ```text kW | domestic | commercial _____ /\ | industrial ___/~~~~\___/ \__ |__/~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +-------------------------------- hour 0 6 12 18 24 ``` Because the classes peak at different times, the **diversity factor** of the system is greater than 1, so the generating capacity required is less than the sum of the individual maximum demands. The values above are typical textbook ranges and vary from system to system. ## Check yourself The answer's key points as multiple-choice questions, with the correct option and why. 1. On what basis are electrical consumers classified? A. Purpose of use, size of load and supply voltage B. Only the distance from the substation C. Only the colour of the meter D. Only the age of the connection Answer: A. Consumers are classified by purpose of use, size of load and supply voltage, and each class has a typical demand pattern. (Key point: Basis of classification) 2. Which class has the highest load factor, and why? A. Domestic, because loads run all day B. Industrial, because its load is large and steady (multi-shift) C. Agricultural, because pumps run all year D. Street lighting, because it is the largest load Answer: B. Industrial plants have large, steady loads, giving a load factor of about 60 to 80 %, and they need power-factor correction. (Key point: Industrial load factor) 3. Which pairing of class and typical peak time is correct? A. Domestic - night only B. Commercial - evening C. Street light - dusk to dawn (night) D. Industrial - evening only Answer: C. Street lighting is a fixed night-time load; domestic peaks in the evening and commercial during business hours. (Key point: Peak times) 4. Why is the diversity factor of the system greater than 1? A. All classes peak at the same time B. Classes peak at different times, so the system maximum demand is less than the sum of individual maximum demands C. Industrial load is always constant D. Voltage is the same for all classes Answer: B. Because classes peak at different times, required generating capacity is less than the sum of individual maximum demands. 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