Page 290 - Electrician - TT (Volume 2)

ELECTRICIAN - CITS

Step 9: Calculate the labour charges for entire wiring.
Step 10: Calculate the cost of accessories, base materials(PVC, Batten, cables, hardware etc.) and labour
charges
Step 11: Calculate the total cost of wiring, including 5% contingencies charge.
Before the selection of size of cable and their length, calculate the total load of the house and also to decide
whether 3phase or 1phase.

Total connected load = whole of the load in a building.
Assuming total connected load is 2400W.
Current = 2400 / 240 = 10A.
Assumption of power factor is unity and single phase load.
Hence, copper cable 3/0.036 could be selected for main board.

Length of cable = main cable from meter board to the DB
= 2X 1.5 = 3m of size 3/ 0.36 copper cable
(1.5m is taken as rough value)
ROOM NO 1

A One tube light point
B One light point CIRCUIT 1
C Two fan points
D One 6A 3-pin socket
ROOM NO 2
A One tube light point

B One light point CIRCUIT 2
C One fan point
D Two 6A 3-pin socket
Circuit 1

Sl No Description Quantity Wattage rating Total wattage
1 Tube light(1200mm) 1 50 50
2 Light point 2 60 120
3 Fan points 2 60 120

4 6A, 3pin socket 1 100 100
390W

Circuit 2
Sl No Description Quantity Wattage rating Total wattage

1 Tube light(1200mm) 1 50 50
2 Light point 1 60 60
3 Fan point 1 60 60
4 6A, 3pin socket 2 100 200
370W

277

CITS : Power - Electrician & Wireman - Lesson 104&105