- 1. Illumination Based Problems Vijay Balu Raskar (B.E.Electtrical)
- 2. NOTE:- Before Designing assume following things clearly. Assumptions are required for illumination. Assume Depreciation Factor = 1.2 Assume Maintenance Factor = 0.8 Utilization Factor = 0.6 to 0.9 Assume illumination is free from glare Assume illumination is free from dark shadows Assuming lamps are arranged to give uniform illumination. Reflective index of wall and ceiling is maximum. Selecting a fluorescent tube light Space to height ratio along the length and breadth is less than or equal to 1.5 Assume Height of mounting of Lamp ( as per area) Vijay Balu Raskar (B.E.Electtrical)
- 3. Example -6 • A big hall of (30 m (L) X 12 m (b)) is to be illuminated and illumination required is 50m candles. • Assuming a suitable data and calculated space height ratio, a utilization factor of 0.5, depreciation factor of 1.3, Estimate the no. rating and disposition of lamps.
- 4. Five types of lamps having lumen output as given below, Sr. No Watts Lumens 1 100 1615 2 200 3650 3 300 4700 4 500 9950 5 1000 21500
- 5. Design considerations • Illumination required is = 50 lux. • Depreciation Factor = 1.3 • Let Mounting height be 5m
- 6. Calculation of No. of lamps required • From Table on Lamp Data (Given) We have, AXEXDF 30 X 12 X 50 X 1.3 Gross Lumen Required = 46800 UF 0.5 Number of lamp required, For 100W 46800 29 1615 For 200W 46800 13 3650 For 300W 46800 10 4700 For 500W 46800 5 9950 For1000W 46800 2 21500
- 7. Layout • Taking arrangement as • Let suitable type of lamp will be 300W (take any lamp) i.e. No of lamp = 10 • No. lamps in one row = 5 • No. of rows = 2 • For hall illumination, no black board. • Distance along the length, a = 30/6 = 5m • Distance along the width, b = 12/ 3 = 4 m • DRAW LAYOUT
- 8. S Ratio = Spacing Between Lamps H Height of mounting of Lamp Along Length 5 1 5 S Ratio 1 H Space to height ratio is unity. 4 Along Width 0 .8 5 S Ratio 0 .8 H Space to height ratio is 0.8. Lamps of lower wattage will require more number of fittings and therefore will increases the cost.
- 9. HOME WORK Solved same problem but select different lamp than 300W. Solve for 100W Solve for 200W Solve for 500W Solve for 1000W