A complete residential power distribution system, in addition to the layout of the line, the location of electrical equipment design, how to choose according to the power of the family electrical equipment, voltage grade wire model specifications is particularly important.Users in the new house before the first task is decoration, decoration circuit design and installation is one of the important contents of the housing decoration project.The basic requirements of modern housing circuit decoration are safety, durability and aesthetics.In order to meet these requirements, the following requirements should be met in the selection of wire material models and specifications.

1. Specific requirements for circuit design and installation

(1) the carrying capacity of the wire must meet the requirements of the electrical equipment.That is, long power running.Its heating temperature does not exceed the allowable value.

(2) the voltage tolerance level of lighting wires should meet the requirements of family lighting voltage.That is, their insulation layer can work safely and stably for a long time under 220V lighting voltage.

(3) the mechanical strength of the wire should meet the requirements of indoor wiring.In construction and use process won't be pulled namely break, sprain.

Indoor circuit wiring, wire and other material withstand voltage grade is not difficult to solve, because the product that supplies on the market at present withstand voltage is much in 500V above, can choose and buy directly.The line of modern family installs multi-purpose conduit to be installed darkly below wall body, ceiling or ground level ground, electric wire won't get apparent mechanical stress, need not consider the mechanical intensity of electric wire too much so.In the installation of domestic circuits, we must carefully calculate the carrying capacity of electric wires and other electrical equipment according to the power of household electrical equipment, and determine the model and specifications.Can buy in the market.

2. Main line capacity selection

The number of kilowatts (kW) consumed by household electrical equipment is calculated according to single-phase power supply (220V). The current corresponding to each kilowatt of power is 4.5A, so as to calculate the total electric current of the household.In the estimation should consider the use of electric motors in household appliances, such as refrigerators, air conditioners, washing machines, electric fans, vacuum cleaners and other power motor, the power factor of these motors in 0.Around 8, usually press 0.8. Estimate.Electric heating appliances such as rice cooker, electric cooker, electric stove, incandescent lamp and other power factors can be regarded as 1.The total electric current of the household consists of the following two parts.

(1) electric current for heating appliances and incandescent lighting:

Total kilowatts of electric heating appliance and incandescent lamp ×4.5 a

(2) electricity consumption for electric appliances and fluorescent lamps:

[(total kilowatts of electric appliances and fluorescent lamps) /0.8]×4.5 a

The sum of the above two currents is the sum of the electric current of the household.Family power distribution, generally choose copper conductor plastic, take more than one (2 or 3) wire in the same plastic tube.The cross-sectional area of the selected main line can be selected according to the total electric current of the household.Generally, the sum of household electricity current is less than 10A.I'm going to pick the area to be 1.Conductor of 0mm2: the selected cross-sectional area is 1 when the total household electricity current is between 10 and 14A.Conductor of 5mm2: if the total electric current of a household is between 14 and 19A, the selected cross-sectional area is 2.5mm2 of wire;If the total household electricity current is between 19 and 26A, the selected cross-sectional area is 4.0mm2 wire;The total electric current of a household is between 26 and 34A.And I'm going to pick the area of 6.0mm2 wire: the sum of household electricity current between 34 and 46A.Choose a conductor with a sectional area of 10mm2: choose a conductor with a sectional area of 16mm2: choose a conductor with a sectional area of 25mm2 whose total household electricity current is between 46 and 61A.

3, the choice of branch wire

Family branch refers to the branch from the main switch.To the living room, dining room, kitchen, toilet and each bedroom circuit.The calculation and selection method are the same as the bus part mentioned above.But because these places often have the electric equipment of bigger power, if sitting room, dining room, bedroom has air conditioning, the kitchen has freezer, electric cooker, electric frying pan, take lampblack machine (or exhaust fan), toilet has bath bully, washing machine to wait.Therefore, in the design of power supply lines for these rooms, in addition to the above formula calculation should have enough margin.Pay special attention to the high power electrical power lead must be directly drawn from the home distribution box, do not allow to connect in the home other distribution lines, or serious overload, easy to lead to short circuit, fire and other serious accidents.