C.K.PITHAWALA COLLEGE OF ENGINEERING & TECHNOLOGY,SURAT Branch: Electrical Semester : 5th Group No. 15 Subject :- Element Of Electrical Design

ESTIMATION AND COSTING OF SERVICE CONNECTION Prepared By: PATEL PRIYANK PATEL SIDDHARTH KUMAR PATHAN ARBAZKHAN PATEL ANKIT VALA NARENDRAKUMAR

MEANING OF SERVICE CONNECTION AND TYPES Service connection : suppliers service line come to the consumer location and its connection should be done with costumer internal wiring, cut out, energy meter, or double pole or tri pole should be done with the help of main switch. Cut out and meter is considered for customer only for the safety of cut out and energy meter it should be properly sealed. So no body can touch this seal and device the main switch customer should be put after so if we want to step they we stop immediately Main switch should be sealed properly.

Types of service connection  There are two types of service connection. Domestic service connection. Industrial connection. Domestic service connection :if the small user can use only fans and tube light and used as electrical energy up to 4kw then this types of connection is called domestic service connection. This service connection should single phase,230volt,2 wire method of energy measured by single phase,230 volts capacity energy meter should be used.

 Industrial service connection  If service connection should be supply to small industrial then this type of connection is called industrial service connection in this type service connection 400 volt,3 phase, 4wire method should be used  3 phase 3 wire,4 wire types 5/25 ampere capacity energy meter is used  It should be preferred for light, fan and machinery meter  Sometime flow should be given to energy meter with help of current transformer

Layout and wiring diagram of service connections

 For any project of service connection it is necessary to prepare a layout of service connection and detailed wiring diagram.  So that estimating of the total cost becomes easy and accurate for the project.  It is also necessary to decide in advance what type of service connection is to be provided.

Example:- An industrial establishment having total load of 75 kw is to be provide electrical supply 415v,3 phase 4 wire 50hz by o.h service connection service pole 55 m away s from the meter board Draw the fig of service line p.f = 0.8 lags Total load = 75kw pf = 0.8 The full load current = amp Calculation of length a AC conductor 7/4.39mm-all aluminium conductor =55*3+12m =180m Calculation of length os 3/1/2 core cable underground line=20m Labours charge 7% of material cost

Example:- A small factory having load of 25kw at 415v 3phase 50hz 4wire system of supply it is to be provided with underground service connection the power factor of the load 0.8 lags and factory premises 30m away pole Draw layout of u g service connection The total load current =4304 amp Length of cable =45 m L.charge 7% of total material cost Cable laying charge 60% material cost Transportation and storage 7 % material cost Layout of u.g service connection see fig.