Conventional rules for selection of wire size:
1.5 square mm or 1.5 r.m PVC or VIR copper or aluminum wire is generally used for lighting circuits in our country. And for power circuit 2.5 r.m to 6 r.m pvc or VIR copper or aluminum wire is used.
r.m=standard round conductor multi
r.e = standard round conductor each
Selection of circuit breaker values:
In selecting the value of the circuit breaker, the value of the total current must be calculated for all the loads of the entire house or the value of the total current for all the loads of one room only and the value of the safety factor should be selected by multiplying the values of the safety factor with that value becomes.
Value of circuit breaker = total current X value of safety factor (1.5/2/3)
Required load for a room With wiring diagram:
With wiring diagram: The current value of the circuit breaker and the size of the wire must be determined to properly handle the loads shown in the diagram.
Details of loads shown in figure:
A ceiling fan (1x 80) = 80w
4 LED lights (4X20) = 80 W
1 fridge (1X500) = 500 W
1.5 Ton AC (1×1500)= 1500 w
2 sockets (2 X 200) = 400 W
Total load power = (80 + 80 + 500 + 1500 + 400) w = 2560 W
We know, P = V X I CosO
I = P / V CosO
I = 2560/ 220 X.8
I = 2560/176
I = 15 Amp
Circuit breaker (CB) value = Total current values X Safety factor
= 15 x 2 = 30 Amp [S.F= 1.5-2-3]
Wire size = 4 sq. mm or 4 r.m
Wiring Diagram of Distribution board:
Wiring Diagram of Sub-Distribution Board:
