What size should I use for a household main air switch?

Households generally use a two-pole (i.e., 2P) air switch for total power protection, and a single-pole (1P) for branch protection.

Air circuit breakers

An air switch, also known as an air circuit breaker, is a type of circuit breaker. It is a switch that automatically disconnects whenever the current in the circuit exceeds the rated current.

The air switch is a very important electrical appliance in the low-voltage distribution network and the power drive system, which integrates control and a variety of protection functions. In addition to contacting and breaking circuits, it can also be used to protect circuits and electrical equipment from short circuits, serious overloads, and undervoltages, and can also be used to start motors infrequently.

How it works

There are three types of tripping methods: thermal[1], electromagnetic, and duplex tripping. When the general overload occurs in the line, although the overload current can not make the electromagnetic tripper move, it can make the thermal element generate a certain amount of heat, promote the bimetal sheet to bend upwards when heated, push the lever to disconnect the hook and the lock, break the main contact, and cut off the power supply.

When the line is short-circuited or seriously overloaded, the short-circuit current exceeds the instantaneous tripping setting current value, and the electromagnetic tripper generates a large enough suction force to suck the armature and hit the lever, so that the hook rotates upward around the shaft seat and disengages the lock, and the lock breaks the three main contacts under the action of the reaction spring to cut off the power supply.

The tripping mechanism of the switch is a set of connecting rod devices. When the main contact is closed by the operating mechanism, it is locked in the closing position by the latch. If a fault occurs in the circuit, the relevant tripper will act to disengage the locking hook in the trip mechanism, so that the main contact is quickly disconnected by the release spring.

According to the different protection functions, the tripper can be divided into overcurrent trippers and loss-of-voltage trippers.

Main role

Under normal conditions, the armature of the overcurrent tripper is released; In the event of a serious overload or short-circuit fault, the coil connected in series with the main circuit will generate a strong electromagnetic attraction to attract the armature down and jack the locking hook, so that the main contact is disconnected. The undervoltage tripper works on the contrary, when the voltage is normal, the electromagnetic suction pulls the armature and the main contact is closed. In the event of a severe voltage drop or power failure, the armature is released and the main contact is disconnected.

When the power supply voltage returns to normal, it must be re-closed before it can work, and the voltage loss protection is realized.

Home is 60a.

The total air opening in the room is bipolar, without leakage protection, only the bathroom, kitchen, bedroom, living room socket must be selected leakage protector. At present, there are many counterfeit and shoddy products on the market, and it is best to choose the abb brand, which is more expensive (20A leakage of more than 100 yuan for a genuine product).

The lighting is generally 10A monopole, while the living room socket and bedroom socket are generally with leakage protectors (the new specification requires that leakage protectors must be used). The air conditioner is generally single-designed, and the power supply is supplied with a single-pole air switch. Home use is now generally 60a, if you want to describe it (1 computer, not 11), 40a or 32a.

The principle of selection of home air switches is still based on the maximum operating current. That is, the maximum current that can be set by the selected air switch is greater than or equal to the total power.

Suppose the total power of electrical appliances: the family has 2 air conditioners (4500w water heaters (2000w electric porcelain stoves (1600w computers (500w), 1 refrigerator (600w), 2 TVs (300w).

Total power = 4500 * 2 + 2000 + 1600 + 500 + 600 + 300 * 2 = 14300w

The formula for calculating the total power is: P=UICOS I=P UCOS is launched

Current of the line: i = p ucos = 14300 220*

The maximum setting current of the selected air switch is 63A, which is greater than the total working current of 52A, which is in line with the selection principle. Theoretically, this calculation is correct, but there is a problem. The average household capacity is only 5kw, and it is impossible for them to work at the same time.

According to the above calculation method, the switch cannot play the role of overload protection. The entrance line of the residents of the building is generally the same, and it is basically impossible to reach this level after cutting corners. If it can meet the standard, it is a current of 32A.

Therefore, it is very dangerous to open all the backup large switches, and burn the switch and burn the wire. It is recommended to calculate according to the capacity of the household, and choose between 20a and 32a.

The size of the air switch should match the size of the meter capacity and the size of the power cord. Usually 6 square copper core wire should be equipped with 32-40 air opening, 4 square copper core wire should use 25-32 air opening.

Generally 30a is fine.

The general household air switch should be selected Z-47 series, that is, the air opening of Z-47 C63A, the main switch of the control of each floor with C-45 C 32A leakage protection, and then use the output of this leakage protection to tap the control socket, lighting, air conditioning and other buried Xiang branch control switches, bend the front and the leakage protection of this C32A and the air opening under the sub-base scatter circuit, according to the total power of the electrical equipment connected to the working current of the number behind it.

times (no more than 2 times) of the working current optional it "c after the number" (that is, the current rating), lighting, air conditioning, etc. shunt control "air open": household power supply total control box wiring diagram, should be selected model "z--47 series", should be connected to the total power of the electrical equipment 1, to control the total power supply of a certain floor.

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The so-called air switch, in fact, is a circuit breaker, which plays a great role in the circuit, and life is inseparable from the air switch, which can effectively protect our electricity safety. When we choose, we also have to combine the electricity situation in the home, and there are many models of air switches on the market, and there are many particulars when choosing. Is it difficult, how big should the air switch be used, and how should we choose?

Let's take a brief look at it below.

1. How big is the air switch?

The most advanced air switches on the market mainly include 10 amps, 16 amps, 20 amps, 25 amps, and even 63 amps. The current load of different specifications of air switches is different, so they are used in different places.

1. Divide according to the wire.

If the home is laid with square wires, it is best to use a 10-amp air switch.

If it is a square wire, you can match it with an air switch with a slightly larger power, and choose 16 amps.

If it is a 4 square wire, it can be equipped with a 20 amp air switch.

2. Divide according to the needs of the family.

If it is some electrical appliances with relatively high power, such as water heaters or air conditioners, it is best to use a 20 amp or 25 amp air switch when connecting.

If it is used for indoor lighting, when laying the line, you can use a 10 amp or 16 amp air switch.

When choosing, you can consult a professional electrician, or consult the staff of the specialty store, they have a better idea of what kind of specifications to choose.

2. How to choose an air switch.

1. Choose the right model.

There are many ** models on the market, and generally there are two according to the range of use. If it is industrial electricity, its model is generally with the words DW or DZ. If it is household electricity or lighting electricity, its model number is generally marked with the word C.

2. Choose the right size.

If the air switch is not matched, there will be a big safety hazard.

If it is household electricity, it is more commonly used to use 10 amps, 16 amps or 20 amps.

If it is used for commercial electricity, for example, if it is to open a restaurant, there are generally more electrical appliances used, so you should choose a relatively large power.

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Air switches for home use are all C-curved. Therefore, when it comes to air switches for household use, choose C-curve air switches. The air switch of the C curve is the common C10A, C16A, C20A, C25A, C32A, C40A, C50A and other different models, in which the number is the rated current on behalf of the representative, and the letter C represents the type of trip curve.

The rated current of the air switch must be selected according to the calculated current of the load circuit of the air switch. For example, if the calculated current in the loop is 10A, then it is selected according to the multiplication of 10, which is 12A. Greater than 12A is the 16A air switch, so we should choose the C16A air switch.

What are the functions of the air switch:

1. Leakage protection.

There are more electrical appliances in the family, and when some electrical appliances are used for too long, they will age or leakage, and if the switch is installed in the home, it can play a role in protecting the circuit, and can also block the circuit, and there is a risk of electric shock, so that the user is safer.

2. Short-circuit protection.

When installing the circuit, if the wire is accidentally connected to the wrong one, it will lead to problems with the circuit, at this time, you can use the air switch to protect the circuit, automatically disconnected from the circuit, so that it also plays a role in short circuit protection, but also to protect people's safety.

3. Isolation. When the current is below 30 milliamperes, it is safe for the body, and it can be said that it also plays a role in the circuit.

C32 should be selected on the specifications and models of household switches, C32 means that the rated current of the circuit breaker is 32A, and there is no problem with the water heater used for it. 2 400V circuit breakers are used on three-phase circuits, while 230V circuit breakers are used on single-phase circuits. The 4500A or 6000A behind the circuit breaker model refers to the rated breaking current of the circuit breaker, and for household circuits, 4500A and 6000A are OK.

The plugs of regular electric water heaters are equipped with leakage protection, so that leakage protection can not be installed on the circuit breaker.

Answer: Hello for reference only, I hope to help you, At present, the family uses the air switch (small circuit breaker with leakage protection) of the DZ series, and the common models are the following specifications: C16, C25, C32, C40, C60, C80, C100, C120, etc. When choosing the model of the air switch, it is not that the higher the rated current value, the safer, if the rated current is too large, the expected protection effect will not be achieved.

However, if the rated current is too small, the air switch is prone to frequent tripping, causing unnecessary power outages.

Pay attention to the details of the purchase of air switches: 1Let's start by looking at the weight of the air switch.

Generally speaking, the shell of the high-quality air switch is flame retardant PC plastic, and the inside is pure copper wire, and the more turns there are, the better the quality. 2.Then look at whether the switch surface has the IEC logo.

CCC certification, Great Wall certification, PICC quality certification, whether there are GB10963D and other marks. 3.Secondly, when purchasing a household air switch, you also need to look at the internal arc extinguishing cover.

The arc extinguishing cover is used to extinguish the arc generated when the circuit is short-circuited or overloaded, and if the arc cannot be extinguished smoothly, it is likely to lead to a fire, so it is necessary to choose an arc extinguishing cover with excellent quality.

It is best to choose the medium switch, because this kind of switch is easy to touch, and it is also very good to turn off, and the model is also to choose the medium, and then you must not choose the kind of particularly small, because that is too small and sometimes may not be pinched, these are to pay attention to.

Choose the size of the normal model, choose a large or small size according to the current used in the home and whether the house has large furniture. It should be noted that when the current power used in each room is different, it should be equipped with different air switches.

Is it wrong to choose this large size for the model of the switch? The first point is that the whole switch must master the most basic switch skills, the second point is to master the details of the whole switch, and the third point is to pay attention to the maintenance of the entire circuit.

The rated current of the household air main switch is generally 40 amps or 63 amps.

Generally speaking, the 40 amp main air switch is suitable for households with small residential area and small electrical load, while the 63 amp main air switch is suitable for large residential or commercial places with large electrical load.

However, the specific use of the rated current of the main air switch also needs to be decided according to the specific situation of the house, such as the area of the residence, the power load of the liquid, the type and quantity of electrical equipment, etc.

When using the household air main switch, you need to pay attention to the following things:

1. Pay attention to the use environment: the main air switch should be installed in a ventilated and dry environment, avoiding direct sunlight and humid environment, so as not to affect its normal service life.

2. Avoid electric shock during operation: When using the air main switch, do not directly touch the electrical device with your hands to avoid electric shock accidents, and use protective measures such as insulating gloves.

3. Avoid overload use: When using the air main switch, ensure that the circuit load does not exceed its rated current, so as not to cause safety problems such as overheating, short circuit and fire.

4. Regular inspection and maintenance: The main air switch should be inspected and maintained regularly, and the aging or damaged parts should be replaced in time to ensure its normal operation and safe use.

5. Avoid interference with other electrical equipment: Do not use electrical equipment near the main air switch, so as not to interfere with its normal operation and cause safety accidents. <>