We all know that wires and cables are distributed differently according to the structure of electrical conductors. Cables are divided into 1-core, 2-core, 3-core, etc.
Single core cable: there is only one electrical conductor in an insulating sleeve. A wide range of main uses are home lighting equipment, power plug, central air conditioning, etc. all use single core cable.
Characteristics of single core cable
1. Classification of single core cables
Single core cables include bv cable, RV cable and BVV cable. BVR cable is a multi-core cable with soft raw materials and several tiny copper core wires twisted together.
2. Single core wire color:
The common colors of single core wires are: red, yellow, blue, green, black, white, multicolor (yellow, green) and brown.
3. Advantages of single core cable:
Due to the small cross-section ratio, it is not easy to be oxidized, resistant to the destruction of short-circuit capacity, and has a relatively long service life.
4. Disadvantages of single core cable:
The transmission line is too hard. It is inconvenient to pull wires in some areas. It is not easy to straighten after bending. It is easy to damage the cable after bending for many times.
All cables used at home can use a single copper core cable, while some welders require to buy multi-core flexible cables. In fact, there is no difference in quality. Multi-core flexible cables are just better than single core cables.
Difference between three core power cord and two core power cord:
1. Different uses. Two core cables can only be used for single-phase power supply lines, such as 220V. Three core cable can be used for three-phase power supply or single-phase power supply line with ground wire.
2. Different loads. The maximum load current of three core cable with the same diameter is smaller than that of two core cable, which is caused by the fast and slow heat dissipation of the cable.
3. The number is different. Generally speaking, Brown is the live wire, blue is the zero wire, and yellow and green is the ground wire. Generally speaking, Brown is live wire, blue is zero wire, and there is no ground wire.
4. Different positions. The 3-core difference lies in whether the protective ground wire is in the same position or in the same distribution cabinet with the live wire and zero wire. If it is in the same position or in the same distribution cabinet, it is generally selected to use 3-core cable. If it is not in the same position or in the same distribution cabinet, it is generally selected to use 2-core Cable + 1-core cable, so as to introduce the protective ground wire in other positions.
There are also differences between multi-core and single core cables:
1、 Different conductors
1. Multi core cable: multi core cable has multiple conductors in one insulating layer.
2. Single cable core: a single cable core has only one conductor in an insulating layer.
2、 Different circuit capacity
1. Multi core cable: in the same section, the rated current carrying capacity of multi-core cable is greater than that of single core cable.
2. Single core cable: in the same section, the rated current carrying capacity of single core cable is less than that of multi-core cable.
3、 Different security
1. Multi core cable: under the same load or short circuit, the heating capacity of multi-core cable is greater than that of single core cable, which is more dangerous to use.
2. Single core cable: under the same load or short circuit, the heating capacity of single core cable is less than that of multi-core cable, which is safer to use.
4、 In terms of insulation performance, both single core and multi-core cables need to meet national standards. On the premise of meeting national standards, a certain safety margin needs to be reserved, which can be understood as that the insulation performance is qualified without difference;
5、 In terms of cable use, the heat dissipation performance of single core cable is greater than that of multi-core cable (the same type of cable). Combined with the rated current carrying capacity of single core cable with the same section, the heat generation of single core cable is less than that of multi-core cable under the same load or short circuit, so it is safer to use;
6、 In terms of cable laying, single core cable laying is more convenient and bending is easier, but it is more difficult to lay single core cable over a long distance than multi-core cable;
7、 In terms of cable head installation, single core cable head is easier to install and easy to branch.