1, distribution box after the table should be according to the different power of indoor electrical equipment wiring power supply respectively; High-power household appliances should be wired independently and installed with sockets.
2, wiring, phase line and zero line color should be different; The phase line (L) of the same residence should be uniform in color, the neutral line (N) should be blue, and the protection line (PE) must be yellow-green double-color line.
3. The resistance between wires and between wires and the ground must be greater than 0.5M.
4. All weak current subsystems are of star structure.
5.2~3 feed pipes are introduced into the household information access box from the outdoor. The outlet conduit extends from the home information box to each indoor information socket. The concealed pipes (threading pipes) laid shall be steel pipes or flame-retardant rigid PVC pipes (rigid PVC pipes).
6. The pipe diameter utilization rate of straight pipes should be 50%~60%, and that of bent pipes should be 40%~50%.
7. When there are local interference sources on the routing road and the minimum clear distance cannot be met, steel pipes should be adopted.
8. The straight laying length of concealed pipes exceeds 30m, and a box should be installed in the middle.
9. When the concealed pipe must be bent and laid, its routing length should be ≤ 15m, and there should be no S-bend in this section. When bending continuously for more than 2 times, the junction box shall be installed. All bending is done with a pipe bender, which is the standard turning radius. Three links and four links prohibited by the state shall not be used.
10, and the bending radius of the concealed pipe should not be less than 6~ 10 times of the outer diameter of the pipe.
1 1. There shall be no cable connector in the concealed pipe hole.
12. When wiring the power cord, the cross-sectional area of the conductor used shall meet the maximum output power of the electrical equipment.
13, the parallel distance between wires and heating, hot water and gas pipelines should not be less than 300mm, and the crossing distance should not be less than 100mm.
14, the connector of the wire passing through the pipe should be located in the junction box, the connector should be connected firmly, the tin should be rinsed clean, and wrapped evenly and tightly with insulating tape.
Flexible cord: high price, weak tensile strength, weak corrosion resistance, strong fatigue resistance and low waste recovery rate.
Hard wire: low price, strong tensile strength, strong corrosion resistance, weak fatigue resistance and high waste recovery rate.
The advantages and disadvantages of soft wires and hard wires also determine their use functions and places.
Hard wire: generally, hard wire is used to bury the wall and the ground as the main line;
Flexible cord: Flexible cord is generally used for the power connection line of equipment. There is no difference between the two, only who is suitable for which position. So you can choose hard wire or soft wire according to the location of decoration.
What is the difference in structure?
Flexible cord: it is easier to wear when passing through the pipe and has better heat dissipation. Construction is relatively easy.
Hard wire: it takes a lot of effort to connect the pressure wire, which is not so easy to handle, because it is hard to wear the pipe. But the tension of hard wire is stronger.
What are the advantages of soft wire and hard wire in service life and price?
Hard wire with long service life has obvious advantages, and the copper wire of soft wire is too thin and easy to oxidize.
Price: Hard wire is much cheaper, and soft wire technology is much more.
In terms of use, which is better, soft wire or hard wire?
Multi-strand flexible cable has a large current carrying capacity (but hard cable has a strong carrying capacity in bearing sudden load). However, for general household use, the current basically does not exceed 100A, and a single strand is enough.
Single strand hard wire is superior to multi-strand soft wire in oxidation resistance and service life. Especially if it is used for a long time, the advantage of single strand is still obvious. If the copper wire of some flexible wires is too thin, it is easy to oxidize.
Is it better to use soft wire or hard wire for home decoration?
Theoretically, hard wires are better. Usually, you can pay attention to observe whether the burnt connector at home is a multi-strand flexible cable. Professional electrician's analysis: each copper wire of multi-strand flexible wire is too thin, which is easy to cause damage and oxidation. The actual distribution ratio of current through each copper wire is uneven, and the heat conduction is uneven, which causes some copper wires to be damaged first, then the conductivity decreases, and the resistance increases, further causing more heat and finally burning out.
Moreover, at present, because the soft wire is multi-wire metal, the production is complicated and the cost is high, and then the price has no obvious advantage, so the hard wire is better. Therefore, it is best to use a single hard wire for home use, which is much more reliable and durable. Moreover, the advantage of hard wire is that it is more convenient to install the tube and the price is cheaper than that of soft wire. Construction workers are also more willing to wear hard wire because it is more convenient for construction.
Hard wires are widely used in home improvement for the following reasons:
1, with strong security.
The standard use method of flexible wire is to iron the connector flat or press the nose when wiring, otherwise one of the strands may tilt and connect to the next conductor, causing danger. When decorating a house, soldering will increase the cost and waste time. Some users don't even know that solder is needed, thus laying a safety hazard.
2. Conductivity
Usually, hard wires and soft wires with the same wire diameter have the same conductivity. However, when we are wiring, the cord often breaks several copper wires carelessly, and even some novice electricians or users often peel off half of the copper wires when replacing sockets. This will affect the current carrying capacity of the conductor and accelerate the oxidation of the internal copper wire.
In contrast, there is no single hard wire with a larger diameter.
Step 3 facilitate
When replacing the conductor, the hard wire is laborious, but it can ensure that it is completely pulled out of the threading pipe smoothly. If necessary, the threading steel wire can also be replaced and a new steel wire can be pulled in together.
The rope is easy to break after aging, probably because it was accidentally broken when changing the rope.
4. Economy
As mentioned above, flexible wires are multi-stranded, and the manufacturing process of multi-stranded wires is much more difficult than that of single wire, so the price of flexible wires is higher than that of hard wires. Moreover, hard wires can be recycled after being discarded, and soft wires do not have this characteristic. Moreover, the single copper wire inside the soft wire is thinner and its service life is not as long as that of the hard wire.
Where is a better place to use a flexible cord?
Compared with hard wire, the biggest feature of soft wire is to avoid the skin effect in hard wire (you don't need to know what skin effect is). Therefore, flexible wires are often used for information transmission or secondary control, mainly for signal transmission.
Advantages: the line is soft, suitable for turning and pipe crossing, and easy to install and move.
1, the biggest difference between BV line and BVR line is that BV line is a single hard copper wire; BVR wire is multi-stranded soft copper wire, that is, increasing the number of conductors and reducing the diameter of a single conductor, which is less than1mm.
2. In terms of manufacturing technology, when BVR is drawn, its single strand is thinner and the requirements for technology will be higher.
3. In terms of current, due to the "skin effect" of conductors, the current carrying capacity of multi-strand conductors with the same cross-sectional area is higher than that of single-strand conductors.
4. Therefore, the BVR line with the same cross-sectional area will be more expensive than the BVR line 15%-20%.
Specification for wires for daily home decoration
General applications are as follows:
1, 1.5mm2-lamp, etc.
2. 2.5mm2-High-power electrical appliances, such as air conditioners and electric water heaters. ;
3, 4.0 mm2-especially for large electrical appliances, household lines, or special occasions, such as cabinet air conditioners. Does the master bedroom air conditioner use 4.0mm2 line? I specially consulted the electrical engineer in my unit, and the answer is: the safe power of 2.5mm2 wire is at least 3.2KW, the hanging air conditioner in the master bedroom is 1.5p, and the total power is =1.5 * 735 =1102w. Even considering the starting current of on-hook air conditioner, 2.5mm2 conductor is enough.
The other is the kitchen, which meets the requirements: lighting, range hood, gas water heater, disinfection cabinet, refrigerator and microwave oven can be used at the same time.
If the electric water heater is used in the bathroom at home, it is also recommended to use an independent 4.0mm2 circuit in the bathroom, which can meet the needs of using the electric water heater, yuba, heater and lighting at the same time.