Before designing electrics in your house, apartment, cottage, you must first create a calculation scheme, which will be listed all the expected load on the premises, as well as the length of the individual sections of the cable.To compile such a card and you will need to calculate the electrical load.Correctly charting facility will pick up the electrical wires and cables required sections.In cases where the cable cross-section less than that required for the normal functionality of the powertrain high power cable starts to overheat.And as a consequence is the destruction of the insulation.As a result, the duration of the operation and reliability wiring is greatly reduced.Moreover, overheating of the cable can cause a fire.Such situations happen all the time when the residents (to save) used wire size is less than required.The result is a short circuit and fire.Let's see, what is the calculation of the electrical load.
right choice of switching devices, as well as the cross-section of the cable depends on the various parameters of electrical networks.The most important of them is the electric current load.At the design stage the specified amount can be determined solely by a mathematical method.Very important is considered in calculation of the electric three-phase load, as the load necessary to place them evenly among the phase voltages to prevent misalignment.However, in domestic networks such calculation should be carried out not only in the design of the shield, but also residential.
Calculation of electrical load is held with known values of power electrical devices, the nature of the load, and supply voltage.For single-phase networks used formula for determining the load current: I = P / (U × cosφ), where:
- U - value of the actual voltage (measured in volts);
- cosφ - corresponding to the power factor.
For three-phase networks calculation of electrical loads carried by the following formula: I = P / (1,73 × U × cosφ).
Depending on the selected load power factor.When calculating the reactive load of high power (inductors lighting, electric motors, welding transformers, etc..) Adopted the average value of cosφ = 0,8.In determining the current capacity for resistive loads (heating elements, incandescent), the power factor is approximately equal to one.However, any active load is always a reactive component, so the calculations made use value cosφ = 0,95.
In conclusion, let us recall that electricity does not forgive mistakes, it does not give second chances.Safety and reliability of electrical systems - that aspires to any professional electrician.And no matter where he works: in production or in the private sector.Electrical load - that's one of the most important design parameters that must be considered in any system.
