LIGHTNING & LOAD ESTIMATION

Content…… Introduction Calculate the no of luminaries Distribution of luminaries Design no of socket outlets required Load Estimation Transformer selection Draw a single line diagram Cable selection BOQ

Introduction

Cont…. Luminous Flux It is about total light emitted. Luminous Intensity(I) Measure the light intensity of a light source in a

given direction Illuminance the luminous flux (lumens) falling on a surface

per unit area normal to the surface. Luminance It is about visual brightness

Calculate no of luminaries N = (E x L x W) (NL x x MF x UL x LLd)

E = Required Illuminance (Lux level) L = Room Length (m)W = Room Width (m) NL = Number of lamps in each LuminaireN = Number of Luminaires = Lamp fluxM = Maintenance FactorUF = Utilisation FactorLLD = Lamp Lumen Deterioration Factor

Required Illuminance (Lux level)

Place to place change the required Lux level

Depend on type of working situation

So we can summarized the lux level

Recommended Lighting Levels

Number of lamps in each Luminaire

Lamp flux

Utilisation Factor The amount of light reaching a point depends

on the direct contribution from the luminaries and on the indirect contribution reflected from the room surfaces.

So we have to consider that indirect contribution also.

The figure indicates the reflectance of the1.Ceiling 2. Walls 3. Floor\Working plane. 731 corresponds to a reflectance 0.7 for the ceiling, 0.3 for the walls and 0.1 for the working plane.

Cont…. Room Index R.I = (LXW)/ [(H1-H0)X(L+W)]

Where,L = Room Length (m)

W = Room Width (m)

H1= Height of luminaries' light emitting surface

H0 = Height of the working plan

Cont….

Maintenance FactorThe Maintenance Factor is defined as the ratio ofAverage 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.

It is always less than 1.

Lamp Lumen Deterioration Factors For Commonly Used Lamp Types

Distribution of luminaries

Design no of socket outlets required No of socket outlets varies place to place

in a building. we should have a better knowledge about that.

It depend user requirement Shop House Office Factory We use 5A,13A,15A sockets.

Load Estimation 10*(1+(2-1)*0.2)

36*12/0.7/230

18*10/0.7/230

Transformer selection

We have different size transformers30 kVA50 kVA1000kVA1600 kVA

Draw a single line diagram

Cable selection

We can select cable size for the design load. we can get cable size using catalog.

We have to check that cable is suitable.

Selected cable must be acceptable.

BOQ(Body of Quantity)