live wire L, neutral wire N and ground wire PE must have the same cross-sectional area? Can the neutral line be smaller? Can the ground wire be smaller? Let's take a look below.
First of all, it is very certain: in the home decoration circuit: whether it is the main incoming line or the branch line of each circuit, the cross-sectional area of the live wire and the neutral wire must be the same. In other words, the live wire and the neutral wire must be the same thickness. Remember it!
So why must the live wire and the neutral wire be the same thick? The reason for this is very simple. I believe many electricians, including friends with some common sense in electricians, know:
1, household electricity is single-phase electricity, live wire and neutral wire connect the load. Whether it is the main circuit or branch circuit, the current through the live wire and neutral wire are the same, and the cross-sectional area of the wire must be the same, otherwise the load will definitely burn out if it is high.
2. Generally, household electricity is single-phase electricity. In three-phase electricity , under load balance, the neutral wire can be slightly thinner, and there is almost no three-phase electricity in the home, so we won’t say much.
It is very easy to understand that the neutral wire N is as thick as the live wire L, but then again: the ground wire is the most easily overlooked in household electricity use, and it is also the most important place. The cross-sectional area of the ground wire in household electricity has always been a place of dispute between electrician friends.
Some masters said: The ground wire does not usually pass through, so you can use a smaller one, 1.5² or 2.5². Some masters said that the ground wire is as important as the live wire L and the neutral wire N, and the same cross-sectional area should be used. In the home distribution, how should you choose the cross-sectional area of the ground wire?
In household electricity use, that is, household line is generally less than 16², the standard specifications of the ground wire: the ground wire is as thick as the live wire, the ground wire is as thick as the live wire, and the ground wire is as thick as the live wire, and the important things are said three times.
So why should the live wire L, neutral wire N, and ground wire be the same thick in the home line? First of all, let’s make it clear: the household entry line is generally less than 16 square meters, basically 10² is enough!
1, the electrician specifications promulgated by the state, and the national standard clearly stipulates the safety operation specifications of electricians.
As shown in the figure:
0 Does the safety operation specification look very complicated? Let’s summarize:
1, single-phase household electricity with a phase cross-sectional area below 16². The cross-sectional area of the ground wire needs to be as thick as the cross-sectional area of the live wire L.
2, the cross-sectional area of the phase line is 16²~35², and the cross-sectional area of the ground line can be 16².
3, phase line has a cross-sectional area of more than 35², and the cross-sectional area of the ground line can be selected as: phase line/2.
The above descriptions are based on the cross-sectional area of the phase line as reference and are standardized by the national standards.
2, an important role of ground wire in household electricity!
ground wire is an important guarantee for protecting the safety of household electricity, and to a certain extent is equivalent to the "lifeline".
1. Under normal circumstances, the ground wire is not charged in household electricity, so it is easy to be ignored, so the ground wire does not play a critical role in the event of an accident.
2. Generally, the ground wire is connected to the metal shell of the home appliance. When leakage occurs due to the aging of the equipment insulation, the leakage current will flow through the ground wire. If the detection value of the leakage protector exceeds the set value, it will trip protectively! If there is no ground wire, a leakage circuit will be formed when a person touches the metal shell of an electrical appliance, and electric shock will naturally occur, which is very insecure!
Summary: Say important things three times, in household electricity use: live wire L, neutral wire N, and ground wire as thick! The live wire L, the neutral wire N, and the ground wire is as thick as! The live wire L, the neutral wire N, and the ground wire is as thick as! Household electricity, safe electricity! It is not recommended to use wires with a small cross-sectional area in order to save some money when decorating household electricity. This will not only affect safety, but also leave hidden dangers.
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