How is the circuit breaker wired? Is null line left or right?
General electrician will advise the owner to install circuit breakers in order to protect the safety of home electricity. This is because the circuit breaker can automatically trip to cut off the power when the home line fails, thus reducing the loss of accident. But do you know how the circuit breaker is wired? Is it also left null line right fire line? See what the electrician says.
1. What is a circuit breaker?
A circuit breaker is a switching device capable of closing, carrying and breaking the current under normal circuit conditions, and of carrying and breaking the current under abnormal circuit conditions (including short circuit conditions) within a specified period of time. It is a kind of switch, but different from the switch we usually use, the circuit breaker is mainly to cut off the current of high-voltage circuit, when our system failure, can quickly cut off the current, so as to prevent the serious development of the situation, to protect people's property. It's a good safety protection device.
Using circuit breaker makes our life at ease, it gradually into people's lives, to bring us a safer life.
2. Left null, right fire
I didn’t know the meaning at the first time. Gradually, as I learn more, I came to know that the so-called “left null, right fire” is just the socket order -- facing the jack, the left jack is the null line, the right jack is the fire line, that's all.
Socket in the wiring, may not be left null right fire. Some terminals are arranged horizontally, but when you face them (the back of the socket), they are in the opposite order of the sockets. Some terminals are arranged lengthwise, not to mention left and right.
herefore, it is still necessary to follow the label of the terminal post when connecting the wires. If it is marked with L, the fire line will be connected. N represents null line.
3. Wiring position of null line and null line
Every leakage switch must be connected to null line. If there is no null line, it’s because of wrong connection. Household leakage switch, according to the number of poles, can be divided into two kinds: 1P leakage and 2P leakage.
Both switches have two sets of terminals (one in and one out counts as one set). One of the two groups of terminal posts with leakage of 1P has the mark of N. When wiring, null lines should be connected to this group of terminal posts and the other group for fire lines. Don’t care about the left null right fire. The null line and fire line’s direction of the switch is not fixed, and the order of the terminals of different brands and models is different. When wiring, the position of the actual N terminal shall prevail.
There is no identification of the two blocks of 2P leakage, which means that we can choose the wiring order arbitrarily. However, it is generally recommended to refer to the 1P leakage wiring sequence in the distribution box to ensure the same wiring sequence between the two. So the line arrange will be better look and more convenient for maintenance in the future.
No matter what kind of leakage switch, do not connect the null line to the switch.
4. How should the circuit breaker be connected?
Let's take a 2P circuit breaker as an example, face the circuit breaker like the following picture.
The upper two terminals are usually the incoming terminal and the lower two terminals are the outgoing terminal. Since this is a 2P circuit breaker, it can control the opening and closing of two circuits. If there is a capital N on one side of the terminal, this terminal is connected to zero line, and the other is connected to fire line.
In fact, circuit breakers like the ones above are usually very powerful (for the power used by a household). In order to be safe, several 1P circuit breakers will be added at the back of the circuit. Such circuit breakers are generally of low power.
For the circuit breaker of 1P, it is ok to directly connect a live wire from the 2P circuit breaker. Of course, for the circuit breaker of 2P, you can continue to connect a fire line and a null line. If there is no sign of N on the circuit breaker, it is generally followed by the left fire and right null.
5. If the wire is reversed, what will happen?
Connect the wrong null line and fire line for 2P circuit breaker and 2P leakage circuit breaker is no big trouble. The only impact is that it seems not concise, inconvenience for maintenance because expert needs to re-find the null line and fire line.
When disconnected, the 1P+N circuit breaker and 1P leakage circuit breaker can only disconnect the fire wire----the line connected to the unmarked terminal. If the null line and fire line is wrongly connected, when the circuit breaker is disconnected, the null line is actually disconnected. Even though there is no current in the circuit, there is still a voltage. If human touches it, he'll get an electric shock.
The null line of 1P circuit breaker is on the null discharge, so it is not easy to connect wrong. The consequence of wrong connection of 1P circuit breaker is the same as that of reverse connection of null line and fire line of 1P+N circuit breaker.
Post time: Jun-28-2022