Circuit decoration is a very important part of home decoration. Every detail involved cannot be ignored. It is a big responsibility to select wires. If the wire configuration is unreasonable or use inferior wires, there is a hidden danger of electrical fire. It even endangers the safety of people's lives and property. Therefore, we must make reasonable choices and use according to different places.
One: wire specifications
BV: It is a single-core wire of copper wire, which is relatively hard, also called hard wire.
BVR: It is a single-core wire with multiple strands of copper wire twisted together, also called a cord.
RV: It is also a soft wire. It is a single-core wire with more strands of copper wire twisted together.
BVVB: It is a hard sheathed wire, that is, two or three BV wires are sheathed together.
RVV: It is a soft sheathed cable, that is, two three or four RV wires are sheathed together.
The wires used in the home decoration are generally single-strand copper core wires. BV or BVR can be selected. Multi-strand copper core wires can also be used, which is convenient for electrician threading pipes.
Two: wire cross-sectional area
The selection of household wire specifications should be based on the total power of the household appliances, and then select the appropriate wire and cable according to the maximum current carrying capacity of the wires of different specifications.
Wire load current safety value (partial): (mm2 mm2)
1.0mm2 copper core wire allows long-term load current safety value: 6A--8A;
1.5mm2 copper core wire allows long-term load current safety value: 9A--12A;
2.5mm2 copper core wire allows long-term load current safety value: 15A--20A;
4.0mm2 copper core wire allows long-term load current safety value: 24A--30A;
6.0mm2 copper core wire allows long-term load current safety value: 32A--45A;
Common conductor cross-sectional area: 1, 1.5, 2.5, 4, 6, 10, 16, 25, 35, 50, 70, 95, 120, 150, 185, 240 mm2;
Three: the calculation method of power
Power P = voltage U × current I
1.0mm2 copper core wire maximum power P = 220V × 8A = 1760W
1.5mm2 copper core wire maximum power P = 220V × 12A = 2640W
2.5mm2 copper core wire maximum power P = 220V × 20A = 4400W
4.0mm2 copper core wire maximum power P = 220V × 32A = 7040W
6.0mm2 copper core wire maximum power P = 220V × 48A = 10560W
Fourth, take the big 3 air conditioner as an example to illustrate the choice of wire specifications:
HP is the input electrical power of the air conditioning unit compressor. 1HP=735W (the power consumption of household air conditioners is related to the input power of the compressor and the running time of the compressor)
Input power: 3 × 735 = 2205W
Maximum current: I= P/U= 2352/220 = 10.69A
Each 1mm2 wire can withstand current 6A~8A
10.69A / 8A = 1.336 < 1.5 10.69A / 6A = 1.782 〉1.5
It can be seen that the large 3 air conditioner 2.5mm2 copper core wire can be used. If the auxiliary heating is taken into consideration, it is better to use the 4.0mm2 copper core wire, which has a protective effect on the line system.
In the same way, a 1.5mm copper core wire is sufficient for a 1.5-ply hook-up air conditioner.
Five: use wire loop distribution and precautions
(1) The cross-sectional area of household electric wires mainly has three specifications:
1.5 square, 2.5 square, 4 square and 6-10 square.
1.5 square copper core wire: generally used for lamps and switch wires, the ground wire in the circuit is also generally used, and the two color lines are more, so as to distinguish colors.
2.5 square copper core wire: generally used for the plug line and part of the branch line.
4 square copper core wire: special line for circuit main line and air conditioner, electric water heater, etc.
6-10 square copper core wire: mainly used for the main trunk line, almost no use in home decoration or a small amount.
(2) Circuit loop distribution:
One loop for each air conditioner, 2.5 square copper core wire for 1.5P or below air conditioner, and 4.0 square copper core wire for 3P air conditioner.
A circuit in the kitchen with 4 square copper core wires.
One loop for each bathroom, with 4 square copper core wires.
Ordinary sockets in other spaces are divided into two loops, using 2.5 square copper core wires.
The lighting is divided into two loops, using 1.5-2.5 square copper core wires.
In addition to the lighting circuit and the hanging air conditioning circuit, other circuits are controlled by the leakage protection circuit breaker, and each circuit must have a ground wire.