EE4503 Electrical Systems Design Load Calculation

Topics Load Calculation (E.I.T.) Load Calculation by Adding Branch Circuit Load Calculation for condominium Load Estimation

Load Calculation (E.I.T.) lighting Building Lighting (VA) Demand Factor (%) Residential Area  2,000 > 2,000 100 35 Hospital  50,000 > 50,000 40 20 Hotel, Condominium  20,000 20,001 – 100,000 > 100,000 50 30 Warehouse  12,500 > 12,500 Other

Load Calculation (E.I.T.) receptacles Total Load from Receptacle Demand Factor (%) Non residential area  10kVA 100 > 10kVA 50 Residential area 𝐿 𝑚𝑎𝑥 +0.4 𝐿 𝑟

Load Calculation (E.I.T.) Demand Factor of Appliances Building Lighting (VA) Demand Factor (%) Residential Area Kitchen Hot Water Air Condition 10A+30% of extra first two + 25% of other 100 Office, Store First maximum device + 80% of the second max. + 60% of the rest 100% of the largest + 25% of the rest Hotel, Other Same as Office 75

Load Calculation by Adding Branch Circuit Add of all branch circuit Then multiply by the demand factor Number of Panels Demand Factor (%) 1 2-3 4-6 7-10 > 10 100 90 80 70 60

Load Calculation for Condominium Load: common area + individual room Type Number of Rooms Coincident Factor (%) Residential 1-10 11-20 21-30 31-40 > 41 90 80 70 60 50 Non residential > 11 100 85

Load Estimation Quick estimate of the load Many common tables, just refer to one

Load Estimation http://static.schneider-electric.us/assets/consultingengineer/appguidedocs/section3_0307.pdf

Load Estimation http://static.schneider-electric.us/assets/consultingengineer/appguidedocs/section3_0307.pdf

Load Estimation (E.I.T.) lighting Type VA/m2 School 25 Computer Center, Meeting Room, Kitchen 20 Walk way, Balcony 8 Cafeteria 18 Hospital – Operation Room 100 Hospital – Patient Room 14 Office, Shopping Store 30 Drawing Room 60 Laboratory 50

Load Estimation (E.I.T.) receptacles Type VA/m2 Auditorium, Cafeteria, Church, Sport Complex 2 Drawing Room 7 Hospital 10 Machine Room 15 Office School

Load Estimation (E.I.T.) air condition Type VA/m2 Bank 80 Department Store 50 Hospital 70 Office Grocery Store 90 Cafeteria

Reference Electrical Systems Design: ประสิทธิ์ พิทยพัฒน์ Depend on the area, end-user can connect to the “meter” of the authority in three ways.