As a low-voltage circuit breaker for power distribution, the selection mainly includes the following aspects:

First, according to the workplace, meet the requirements of its type and technical parameters;

Secondly, after the varieties and specifications of the circuit breaker are preliminarily determined, we should consider its cooperation with the upper and lower electrical appliances in terms of protection characteristics to meet the requirements of selective protection as a whole;

Finally, check the choices item by item.

How many A's do you choose for home air switch?

Choose the household air switch according to the purpose of the circuit.

Air switch (circuit breaker), also known as air switch, is a common low-voltage protection appliance, which can realize short circuit, overload and other functions. Circuit breakers are used as main power supply protection switches or branch protection switches in household power supply. When short circuit or overload happens to residential lines or household appliances, it can automatically trip and cut off the power supply, thus effectively protecting these devices from damage or preventing the accident from expanding; Usually, the bipolar (2P) circuit breaker is used as the main power supply protection, and the unipolar (1P) is used as the branch protection. If the rated current of the circuit breaker is too small, the circuit breaker will trip frequently, causing unnecessary power failure. If it is too large, the expected protective effect will not be achieved. Therefore, it is very important to choose the rated capacity current of circuit breaker correctly in home decoration. Generally, the specifications of small circuit breakers are mainly divided into 6A, 10a, 16A, 20A, 25A, 32A, 40A, 50A, 63A, 80A and 10A according to the rated current.

For example, the air switch of 10A is usually used for lighting circuit, the air switch of 16A is used for outlet circuit, 20A or 25A is used for water heater and air conditioner, and 63A is used for main brake.

References:

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How do you choose to open a room?

1, should be equipped with a master switch with leakage protection. Leakage protection is to get an electric shock or trip if there is something wrong with the electrical appliance, just for safety. The main switch needs leakage protection, so the size of the main switch depends on your needs. At the suggestion of electrician and independent designer, I ordered 2P63A. Three rooms must be enough. In fact, a room with two rooms and 40A is enough, and the price is not much different. Others suggest that air conditioners should be equipped with leakage protection, which is expensive and unnecessary.

2. Circuit loop. The electricity in the home needs to be divided into several roads, so as to ensure that all the roads are sacrificed and the others can continue to be used. Now it is basically divided like this:

The air conditioner has an independent circuit. It is recommended to have 3 air conditioners 32A or 25A in the living room, either wall-mounted 25A or 20A. I have assigned them to Koryo.

There are 1 circuits 25A or 20A in the kitchen alone.

The toilet separation circuit 25 or 20A

Lighting all lighting primary circuits 16A

Sockets: One loop 20A is used for all sockets.

If the refrigerator needs a separate circuit, it doesn't need to be with the kitchen. Therefore, if there is space, the circuit boxes will be arranged all the way. 16A

My home is eight lines, and then the main switch and leakage protection are four lines, so there are always *** 12 lines. Then if you don't think it is necessary to leave extra space, the box of 12 loop is enough.

How to select air switch

The main function of air switches and fuses is to protect transmission lines. As we all know, all transmission lines have a specific maximum current value. If the actual current exceeds this specified value, the heat generated by the conductor will burn the insulation and even cause a fire. In order to avoid this accident, an air switch or fuse is installed in the circuit. When the current is too large, the air switch or fuse automatically cuts off the circuit and plays a protective role. If the air switch is selected only according to the total power of the electrical appliances used in the circuit, as in the above example, when there are too many electrical appliances in the circuit and the total power is too large, the transmission line may be burned, but the air switch will not trip, so the line cannot be protected. Therefore, when selecting the air switch, the maximum current that the transmission conductor can bear should be considered first, and the air switch should not be selected only by the total power of the electrical appliance.

The air switch has two important technical parameters: tripping current (Im) and rated current (In). Trip current is the maximum disconnection current when the air switch trips (i.e. trips) after the distribution line is overloaded or short-circuited. Rated current refers to the current that the air switch can pass for a long time. As long as the actual current in the circuit does not exceed this current value, the equipment is allowed to work for a long time.

In practical application, in order to protect the power supply line, the tripping current of the air switch must be less than the maximum allowable current of the power supply line, and its rated current should be equal to or slightly greater than the maximum normal working current of the distribution line.

When adding new high-power appliances to household circuits, the bearing capacity of power supply lines should be considered first. If the actual working current exceeds the maximum allowable current of the power supply line, the air switch with higher rated current should not be blindly replaced. When it is really necessary to use electrical appliances, the lines should be reformed, such as replacing transmission wires and electric meters with large load current, or connecting special lines to high-power electrical appliances, and then selecting appropriate air switches according to newly laid power supply lines and actual working current.

How to choose a vacant house?

Your second plan is better. You'll know which circuit has a problem in one trip. It is best to choose an automatic air switch with current protection as the main switch. If you don't increase the capacity in the future, the wires and switches you choose can fully meet your current capacity requirements. Personal opinion, for reference only.

How to choose suitable air switch and leakage protector? 10 point

If the main table only has 16 A, it is wrong. 10 300 square meters house, it is impossible to have only 16 A in total. Your main incoming line with10mm2 is correct. People in the market are basically right. 10 meter, the incoming current per meter is limited to 16 A, the air switch is 16 A, not 32 A, and each room is limited to 3 kW. The switch omitting 2P 16 A can be directly connected to the bottom of each meter, and there is no need to set up a 2P switch separately. You can use two 1P switches to power the lighting of the room and the socket respectively.

Selection of air switch

Assuming that the motor is 1 1KW and the power factor is 0.8, its rated current is I = p */1.732 * u * 0.8 =19.8a.

In general, the instantaneous tripping setting current of motor protection is 12 times the rated current. If the rated current of the load is 20A, the circuit must be quickly disconnected to protect the load and line when the fault current is greater than 240A A. It can be seen that your short delay of 500A is too large.

Theoretically, the rated current should be 1.5 times to 2.1times, and the power consumption and motor protection should be distributed according to the purpose. You can choose to delay or not.

If you are a 1 1KW three-phase asynchronous motor, it is recommended to use it in the case of infrequent starting: DZ47 series idling.

Because you use it under special circumstances, the motor used on the ship is also stipulated by the national standard and the corresponding model. It seems that there are only two uses for driving, but what I said above is industrial. I'm not sure if there is an express provision for using it on ships. I suggest checking whether there is another standard used on board, or asking my colleagues to confirm it. I can only give these suggestions.

How to choose the air switch that matches the air conditioner?

According to the power of the compressor, the greater the load, the greater the air switch. The so-called load is what is usually called a horse.

For example: 1 =735 watts. Current = power/voltage (220 volts). Through this formula, it is not difficult to calculate the load of each path of the controller. Plus a factor of about 30%-50%. It is entirely possible that the air conditioner in the lobby is equipped with 20A air switch, and all others are equipped with 16A air switch.

L 1: lighting-10a-2. 5 square plastic copper wire. L2； Kitchen socket-16a-2. 5 square plastic copper wire. L3； Toilet socket:-16a-2. 5 square plastic copper wire. L4: living room air conditioning socket: -20a-4. 0 square plastic copper wire L5: bedroom air conditioning socket: -20a-4. 0 square plastic copper wire L6: ordinary socket:-16a-2. 5 square plastic copper wire. Main air switch: 40A. This wiring method is more standard and reasonable.

How to select an empty switch?

According to the arrangement of circuits in your home, it can be divided into multiple channels; Lighting, air conditioning, water heater, etc. , choose 10A air switch and open box, zero wire is connected to the wall of open box, live wire is connected in parallel above open box, and electrical equipment is connected below open box.

Selection of air switch

Air switch refers to the air switch. 1P, 2P, 3P is 1 phase. Phase 2 and phase 3 are basically not used for normal civilian use, but are generally used in factories and mines. As for 1.2P, it is simply one switch and two switches. At present, most civil sockets use 2P lighting, while1p.

For your hypothesis, you can have as much money as you want, and you can also ask for a 630A one. Hehe, just kidding. In fact, the air switch is mainly responsible for the electricity safety of your home. Usually, wires and air switches are matched. If the 60-year-old air switch is installed in a 40-year-old house, it will basically not protect it. If there is an overload short circuit, the wire may catch fire in serious cases, and your disclosure has not tripped yet.