1. Electrical Lighting & Cable Selection D.K.Pathirana

2. Part 1 Finding required number of luminaries

3. Types of Electrical Lighting Ambient lighting Task Lighting Accent lighting

4. Ambient lighting

5. Task lighting

6. Accent Lighting

7. Lumen(Luminous flux) [F] The lumen is defined such that… – At frequency of 540×10 12 hz, (i.e., at wavelength λ=555nm) 1 watt of radiant flux (power) will emit 683 lumens of light (luminous flux).

8. Illuminance (E) Defined as the luminous flux (lumens) falling on a surface per unit area normal to the surface. The unit of illuminance is the Lux

9. Luminaries

10. Required no. of Luminaries E x Lx W N = _______________________ NL x  x MF x UF x LLD E= Required Illuminance (Lux level) L = Room length (m) W = Room width (m) NL = Number of lamps in each luminaries N = Number of luminaries  = Lamp flux M = Maintenance factor UF = Utilization factor LLD = Lamp Lumen Deterioration factor

11. Maintanance factor (MF) Can be defined as… Average illuminance on the working plane after a specified period of use of a lighting installation to the average illuminance obtained under the same conditions for a new installation.

12. Lamps Lumen Deterioration (LLD) Manufacturer data…. Examples.. Compact fluorescent 0.85 Mercury vapor 0.79 Metal halide 0.83 High pressure sodium 0.91

13. Reflectance factor the fraction of radiant energy that is reflected from a surface Examples- 70%, 0.8,... Here 10 times the reflection factor….. 1.Ceiling 2. Walls 3. Floor\Working plane.

14. Room Index K = (LXW)/ [(H1-H0)X(L+W)] Where, L= Room Length (m) W= Room Width (m) H1= Height of luminaire’s light emitting surface H0= Height of the working plan

15. Utilization factor Room Index (K) Reflectance 873753731551531311 0.600.390.310.270.290.260.24 0.800.450.370.320.350.320.29 1.000.490.420.360.380.360.33 1.250.530.460.400.420.390.37 1.500.560.490.420.440.410.39 2.000.590.530.460.470.450.43 2.500.610.560.480.490.470.45 3.000.630.570.490.500.490.47 4.000.650.600.510.520.510.49 5.000.660.620.53 0.520.50

16. Example for lighting calculation sheet LengthWidth heigh t of height of theRoom Reflec tion Utiliza tion Maintan ance Deterior ation Requi red Install ed Lam p Number of Requir edTotalCategory of lumin aries working planeindex factor sfactor lux levelflux desi gnlamps in lumina ires loadbulb lum ens each luminaire W 8.385 75.31830.5 1.3016 967 7 3 1 0.520.850.8400 5044 7.01 335 02 7.5294 0388288 LAMP, T8, 1200MM, 36W, 3500K 6.756 443.750.5 0.7730 811 7 3 1 0.420.850.8400 3785 0.98 335 02 5.6494 0016216 15.28 674.84630.5 1.4718 214 7 3 1 0.550.850.8400 7922 9.25 335 02 11.825 26112432 4.073 53.83.750.5 0.6049 23 7 3 1 0.360.850.8400 2529 2.97 335 02 3.7750 7074144 3.366 72.3123.751 0.4984 374 7 3 1 0.360.850.8400 1271 8.64 335 02 1.8983 051272 4.321.9830.5 0.5430 857 7 3 1 0.360.850.8150 5241. 176 112 51 4.6588 235590 FT18W/2G11/ 830 43.223.750.5 0.5489 026 7 3 1 0.360.850.8150 7892. 157 261 01 3.0238 1494144 FT36W/2G11/ 830 1386

17. Recommended Lighting Levels Activity Illumination (lux, lumen/m 2 ) Public areas with dark surroundings20 - 50 Simple orientation for short visits50 - 100 Working areas where visual tasks are only occasionally performed100 - 150 Warehouses, Homes, Theaters, Archives150 Easy Office Work, Classes250 Normal Office Work, PC Work, Study Library, Groceries, Show Rooms, Laboratories 500 Supermarkets, Mechanical Workshops, Office Landscapes750 Normal Drawing Work, Detailed Mechanical Workshops, Operation Theatres 1,000 Detailed Drawing Work, Very Detailed Mechanical Works1500 - 2000 Performance of visual tasks of low contrast and very small size for prolonged periods of time 2000 - 5000

18. Load calculation Part 2

19. Design power socket outlets….. If not given Then analyse…. Ground Floor Quantity Load (Amp) 13A Socket Outlets610*(1+(6-1)*0.2)20.000 Florecent Fittings 2x36W32(36*2*32)/(0.7*230)14.311 Compact lamps (18W)50.559 Compact lamps (36W)40.894 Spot lights40.745 Shaver socket14.000 Basic Lighting Load per Floor40.509Amp. Per Phase load L-GR 13.503Amp.

20. Total new Load for the new wing=49.29Amp Total KVA =(49.29*1.732* 400)/1000 =34.15KVA Add 10 % Extra Capacity= 37.6KVA Amp Closest Next is= 50KVA72.17 Total load for the new wing = Total load for ground floor+1 st floor+2 nd floor…… = 13.503+……+…… =49.29Amp

21. Bill Of Quantity (BOQ) Example Quantity Cost rate(Rs) Total cost(Rs) 01 Phillips 20W CFL warm light 40425 =40*425 =17000 02 Pillips T8 Fluorescent lamp 18W 32600 =32*600 =19200 =17000+192 00 =36200

22. Part 3 Cable selection and Over load Protection

23. Basic types of MCB’s TYPE B TYPE C TYPE D

24. Sizing the cables length of the wire Check the following inequality I n I t  ___________ and I n  I b C a C i C g C f I t = Maximum current capacity of cable for given temp. I b = Design current I n = Rated current of the protective device C a = Correction factor for ambient temperature. C I = Correction factor for thermal insulation C g = Correction factor for grouping C f = Correction factor for semi enclosed fuse. (for MCBs C f = 1)

25. Contd… Refer IEE wiring regulation book Lesser than 4% voltage drop….

26. Selecting a protective device Nature of the load Rated current of the conductor Environmental conditions

27. Contd.. I b  rated current of protective divice  I z Where, I b = Design service current I z = Maximum current carrying capacity of the conductor I f  1.45 x I z Where, I z = Maximum current carrying capacity of the conductor I f = Thermal tripping current of MCCB

28. Single Line Diagram

29. Questions……

30. Thank you