How to Select Suitable Size of Electric Cable & Circuit Breaker I have share Complete Electrical Cables Data in this Post You can understand easily after see this Electrical Cables data.
| Wire Size in (mm²) | Number of Wire and Thickness of Wire | Current Capacity in Amp | Voltage Drop Per 100 Feet |
|---|---|---|---|
| 1 | 1/.044* | 06 | 5 |
| 1.5 | 3/.029* | 07 | 4 |
| 2.5 | 7/.029 | 18 | 2.5 |
| 4 | 7/.036 | 27 | 3 |
| 6 | 7/.044 | 36 | 1.6 |
| 10 | 7/.052 | 43 | 1.3 |
| 16 | 7/.064 | 53 | 1 |
Temperature is also affect on electric line, so we can not neglects the temperature, a electric string have can get different current cargo capacity on different temperature. Then the temperature factor table which help to chose the correct size of electric line.
| Temp Factor | Temp Celsius (°C) | Temp Fahrenheit (°F) | Temp Kelvin (°K) |
|---|---|---|---|
| 1.02 | 25 | 77 | 298.15 |
| 1 | 30 | 86 | 303.15 |
| 0.97 | 35 | 95 | 308.15 |
| 0.94 | 40 | 104 | 313.15 |
| 0.91 | 45 | 113 | 318.15 |
| 0.88 | 50 | 122 | 323.15 |
| 0.77 | 55 | 131 | 328.15 |
| 0.63 | 60 | 140 | 333.15 |
How to Calculate of House Electrical Load
We need plus complete load of House
Example :
First Number of Electrical Item Multiply with his Watt
- Lights 4 x 25 = 100 watt
- Ceiling fan 1 x 80 = 80 watt
- Iron = 1x 1000 = 1000 watt
- Laptop and Mobile charger etc. = 200 watt
100+80+1000+200 = 1380 watt total load
Now Put 20% Additional Load 1380x(20/100) = 276 Watt
The Complete Load is 1380+276 = 1656 Watt
our Supply is 220 volts so 1656/200 = 7.52 amps
Our load is 7.52 amps
(Here is the ceiling fan not a resistive load , it’s a inductive load, for inductive load we also do calculation of power factor, but ceiling fan watt is not to high that we do inductive load calculation , however if we have high number of fan in building then we must fallow the inductive load formula.)
suitable circuit breaker for house wiring (MCB & RCD)
If total House load is 7.5 ampere, there for we chose 10 ampere circuit breaker
If we have water pump motor of 1 HP in our house then
1 HP = 746 Watt
746 / (220 x 0.95) = 3.56
So it’s will take is starting time double current 3.56 x 2 = 7.12
So the suitable size of electric cable is 2.5 mm according table 1.
