Calculation of electric load is made in order that it is correct to pick up the section of wires from which the electrical network will be laid. If all parameters of network (tension, the proceeding current and electrical resistance) correspond each other, then it will serve long, will not overheat, so, will not cause the fire.
Instruction
1. Calculate the maximum load on an electrical network. For this purpose determine the maximum power of consumers who can be at the same time connected to it. Then define material conductor of which conducting will be made. For this purpose take better a copper wire, it has bigger conductivity, than aluminum and not so quickly fuses at increased load.
2. Calculate the wire section necessary for the correct load distribution. For this purpose divide the total power of all consumers which can be found in technical documentation on them into rated voltage in network. As a result the maximum value of current which has to proceed on it (I=P/U) will turn out. Household and industrial networks become so that initial tension was identical on all sockets for connection (sockets).
3. After definition of the maximum current proceeding on network, find the section of a wire of which the network is made. Take into account that the maximum density of current for an aluminum wire is 5 And/mm², and for copper - 8 And/mm². Install the safety lock by the face value which is minimum exceeding the maximum current in a chain to avoid burn-out of conductors in network in case of short circuit.
4. An example If on the seasonal dacha it is necessary to calculate electric load, summarize all capacities of electric devices which can be included in network. Illumination of 10 lamps on 100 Watts (1 kW), the boiler of 4 kW, the fridge of 0.5 kW, the microwave of 2.5 kW, smaller household consumers of 2 kW. In the sum receive the power of 10 kW of =10000 W. As the effective value of tension is equal in household network to 220 V, calculate the maximum current in I=10000/220≈45.46 A network. For the structure of network use the aluminum conductor with a section not less than 45.46/5≈10 mm² or copper 45.46/8≈6 mm². Install the safety lock not less than 46 And.