Select Suitable Size of Electric Cable & Circuit Breaker

Select Suitable Size of Electric Cable & Circuit Breaker

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 WireCurrent Capacity in AmpVoltage Drop Per 100 Feet
11/.044*065
1.53/.029*074
2.57/.029182.5
47/.036273
67/.044361.6
107/.052431.3
167/.064531

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 FactorTemp Celsius (°C)Temp Fahrenheit (°F) Temp Kelvin (°K)
1.022577298.15
13086303.15
0.973595308.15
0.9440104313.15
0.9145113318.15
0.8850122323.15
0.7755131328.15
0.6360140333.15

Whirlpool Refrigerator ARB-884SGYS Electric Diagram

HVAC Solution

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.

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