There are many classification methods for low voltage circuit breakers. Depending on the type of use, a distinction is made between selective and non-selective species. Depending on the arc extinguishing medium, there are air type and vacuum type. low voltage circuit breakers have a wide range of capacities with a minimum of 4 A and a maximum of 5000 A.
What is the function of the low voltage circuit breaker?
What are the operating steps of a low voltage circuit breaker?
How does the overload protection of the low voltage circuit breaker work?
A low voltage circuit breaker, commonly known as automatic air switch, is a low voltage electrical device that can automatically interrupt a faulty circuit and has both control and protection functions. In low voltage circuits, it is used to interrupt and connect load circuits to control the operation and stopping of motors. If the circuit is overloaded, short-circuited, voltage loss and other faults, it can automatically turn off the faulty circuit to protect the safety of the circuit and electrical equipment. Its protective effect parameters can
be artificially adapted to the requirements of electrical equipment, and it is convenient and reliable to use. It is worth noting that after disconnecting the contact of the low voltage circuit breaker, the actuation handle is still in the "closed" position, and the handle must be moved to the "open" position, and then to the "closed" position. Position.
The operation of the low voltage universal circuit breaker is divided into electrical and manual operation.
Electric operation, first press energy storage button, after inserting the energy storage press close button. If there is no stored energy, press the close button directly. Manual operation, use the special control handle on the universal circuit breaker to manually store the energy up and down on the universal circuit breaker, and press the power button on the circuit breaker after the indicator is attached.
The low voltage circuit breaker uses time delay protection for long-term overload protection. When a thermally actuated (bimetal element) is used for long-term overload protection, its action source is i2r, and the effective value of AC is equal to the average value of DC, so no change is required. However, if the secondary current heating of the current transformer is adopted for high current specifications, the transformer cannot be used in the DC circuit and cannot be used.
If the long-delay overload trigger of low voltage circuit breaker is completely electromagnetic (hydraulic type, namely oil cup type), the time delay trigger characteristics should change, and the minimum operating current should be increased by 110% to 140% . Therefore, the fully electromagnetic AC trigger unit cannot be used in the DC circuit (if used, it must be redesigned).
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The miniature circuit breakers are characterized by small size, simple structure and convenient operation. The contact material of the DC miniature circuit breaker is made of copper-based alloy and has been specially treated to reduce the contact resistance and reduce the temperature coefficient.
1.The upper limit of ambient air temperature must not exceed +40℃, the lower limit must not be lower than -5℃, and the average temperature value of 24 hours must not exceed +35℃;
Note 1: If the lower limit is -10 °C or -25 °C, the user must inform the manufacturer when ordering;
Note 2: If the upper limit exceeds +40℃ or the lower limit is below -25℃, the user should negotiate with the manufacturer.
2. The height of the site must not exceed 2000 m;
3. The relative humidity of the atmosphere does not exceed 50% if the ambient air temperature is +40 °C, and at lower temperatures a higher relative humidity is allowed, e.g. 90% at +20 °C. condensation should take appropriate measures;
4. degree of pollution: 2;
5. Installation category: Class II and Class III;
6.The external magnetic field of the installation site should not exceed 5x the earth's magnetic field in any direction;
7. Generally installed vertically, with a tolerance of 2° in each direction;
8.There should be no significant vibration or vibration at the installation site.
The miniature circuit breaker is characterized by advanced structure, reliable performance, strong switching power, beautiful appearance and compact appearance. It is mainly used in places with alternating current 50 Hz or 60 Hz, rated voltage below 400 V and rated operating current below 63 A. It is used for overload and short circuit protection of lighting, distribution lines and equipment in office buildings, residential buildings and similar buildings, and can also be used for the rare on-off operation and conversion of lines. Miniature circuit breakers are mainly used in various places such as industrial, commercial, high-rise and residential buildings.
1. Breakable contact connection. It consists of fixed contacts and movable contacts.
2. Equipment consisting of metal cylinders or insulating cylinders incorporating separable contact connections and arc extinguishing devices and transmissions.
3. The transmission device that drives the contact.
4. Arc extinguishing equipment.
When the miniature circuit breaker breaks the circuit, it uses a mechanical method to separate the moving contact and the fixed contact of the miniature circuit breaker. When closing, the movable contact and the fixed contact are closed by the opposite mechanical movement. During the closing and breaking of the load circuit, an arc is generated between the fixed contact and the movable contact. The arc generated during the opening process is much stronger than during the closing process. If the cut-off current is very large, especially when breaking a short circuit, the arc is very large, and it is often very difficult to disconnect the circuit.
JIELI Electrical maintains close relationships with customers in miniature circuit breaker industry, and is committed to strengthening p
roduction and operation, improving quality and safety.
At the regular press conference held by the Ministry of Commerce on September 10, the spokesperson Gao Feng introduced that the 128th China Import and Export Fair (Canton Fair for short) will be held online from October 15th to 24th and will last for 10 days. Gao Feng said that continuing to hold the Canton Fair online will help further play the role of the Canton Fair's all-round opening up platform, promote the stable and healthy development of foreign trade under normal epidemic prevention and control, and facilitate the smooth flow of the foreign trade industry chain and supply chain. We will work hard to provide better and more convenient services for exhibitors and merchants. Welcome Chinese and foreign enterprises and businessmen to actively participate in the exhibition and negotiate purchases.
The 132th China Import and Export Fair (Canton Fair for short) will be held online from October 15th to 24th and will last for 10 days. continuing to hold the Canton Fair online will help further play the role of the Canton Fair's all-round opening up platform, promote the stable and healthy development of foreign trade under normal epidemic prevention and control, and facilitate the smooth flow of the foreign trade industry chain and supply chain. We will work hard to provide better and more convenient services for exhibitors and merchants. Welcome Chinese and foreign enterprises and businessmen to actively participate in the exhibition and negotiate purchases
The miniature circuit breaker is also a circuit breaker product with a wide selection and quantity, and its main function is to protect the electrical junction distributor device of the building. It is suitable for overload and short circuit protection of AC 50/60 Hz, rated voltage 230/400 V, rated current up to 63 A, and also can be used for the rare operation and conversion of lines under normal conditions, mainly for industry, commerce, high rise and residential buildings and other places.
The miniature circuit breakers consist of drives, contacts, protective devices (various triggers) and arc extinguishing systems. Its main contacts are manually operated or electrically closed. After closing the main contact, the release mechanism locks the main contact in the closed position. The coil of the overcurrent trigger and the thermocouple of the thermal trigger are connected in series with the main circuit, and the coil of the undervoltage trigger is connected in parallel with the power supply. In case of short circuit or strong overload of the circuit, the anchor of the overcurrent trigger is tightened to release the free trigger, and the main contact disconnects the main circuit. When the circuit is overloaded, the thermocouple of the thermal trigger heats up and bends the bimetal, thereby activating the free release mechanism. In case of undervoltage in the circuit, the anchor of the undervoltage trigger falls off.
1) The installation of the miniature circuit breaker should meet the requirements of GB13955-92 standard and product manual.
2) When installing the miniature circuit breaker, the power supply line, power supply mode, power supply voltage, and grounding type of the system should be fully considered.
3) The rated voltage, rated current, short-circuit shutdown capacity and shut-off time of the miniature circuit breaker shall meet the requirements of the protected power supply line and electrical equipment.
4) The installation and wiring of the miniature circuit breaker should be correct. Special attention should be paid to the wiring of the residual current miniature circuit breaker in single-phase, three-phase three-wire and three-phase four-wire power supply systems of different grid grounding forms.
(1) The arc extinguishing chamber is formed into a polygon;
(2) coating a layer of conductive carbon film on the inner wall of the arc extinguishing chamber;
(3) use graphite as an arc extinguishing agent;
(4) Increase the number of auxiliary contacts, etc.
JIELI Electrical is not only a production service provider solving supply chain problems, but also a manufacturer offering OEM and ODM production services. Do you need help with low voltage miniature circuit breakers? Fill out this form to contact us. JIELI Electrical has been active in the low voltage miniature circuit breaker industry for almost twenty years.
There are many classification methods for low voltage circuit breakers. Depending on the type of use, there is a selective type (protective device parameters are adjustable) and a non-selective type (protective device parameters are not adjustable). Depending on the arc extinguishing medium, there are air type and vacuum type.
What is the use value of low voltage circuit breakers?
What parameters should be considered when selecting a low voltage circuit breaker?
What is a low voltage circuit breaker?
low voltage circuit breakers are electrical devices used for switching, controlling or protecting circuits with AC voltage of 1200 V and DC voltage of 1500 V. low voltage circuit breakers are an important part of the electrical industry and basic accessories in the machinery industry. In the power distribution system, low voltage switchgear mainly consists of various low voltage circuit breaker components. The functions and performances of low voltage circuit breakers play a crucial role. More than 80% of the electrical energy generated by power generation plants is distributed and used via low voltage circuit breakers. For each additional 10,000-kW power generation system, approximately 20,000 pieces of different low voltage circuit breakers are required to adjust them. Industrial automation systems also require various control panels, consoles, controllers and other products consisting of low voltage circuit breakers.
The type of circuit breaker includes the number of phases, the number of poles, the rated frequency, the arc extinguishing medium, the closing method and the shutdown method.
2) Rated power of the main circuit:
Main circuit ratings are:
rated operating voltage; rated current; rated short-term switching capacity; Design short-term current resistance.
The rated current of the universal circuit breaker is also divided into the rated current of the main circuit and the rated current of the frame plane.
3) Work system assessed:
The rated load system of low voltage circuit breakers can be divided into two types: 8-hour system and long-term system.
4) Subcircuit parameters:
The auxiliary circuit parameters of low voltage circuit breakers are mainly the characteristic parameters of auxiliary contacts. Universal circuit breakers usually have 3 pair closers and 3 pair openers for signal devices and control circuits; Compact circuit breakers usually have no auxiliary contacts.
low voltage circuit breakers are also called automatic air switches or automatic air circuit breakers or short circuit breakers. It is an electrical device that has both manual switching functions and automatic power failure, undervoltage, overload and short circuit protection. It can be used to distribute electrical energy, rarely start asynchronous motors, protect power supply lines and motors, etc. Its function corresponds to a fuse switch and overheating relay and other combinations. In addition, it is generally not necessary to replace parts after the residual current is interrupted, and it is widely used.
JIELI Electrical Engaged in research and development, production and supply chain management of MCB, RCCB and related supporting products.
We all know that circuit breakers play a big role in our power consumption process and can effectively ensure the safety of our power consumption. And did you know that in addition to high voltage circuit breakers, there are also low voltage circuit breakers? What role do low voltage circuit breakers play? What other species?
What problems should be considered when using low voltage circuit breakers?
What are the characteristics and functions of low voltage circuit breakers?
How does the low voltage circuit breaker perform the drawer wiring?
1. Improper installation and adjustment
Whether the installation and setting are correct is one of the basic factors affecting the normal operation of the low voltage circuit breaker. There are many operational accidents because the product is not assembled, adjusted and put into operation strictly according to the manufacturer's regulations. In general, there are three situations: (1) The auxiliary switch is set incorrectly. (2) The screw is not tightened and the pin is not opened. (3) Improper placement of the sealing ring.
2. Improper operation and maintenance as well as incorrect operation
Improper operation and maintenance of low voltage circuit breakers is another important cause of operational accidents. There are three common aspects: (1) The oil circuit breaker has too little oil. (2) Poor insulation. (3) Poor mechanical maintenance.
①The low voltage circuit breaker has strong switching power.
②The low voltage circuit breaker has good protective properties and can completely disconnect the line in a very short time.
③ The free release device of the low voltage circuit breaker has a locking effect. If the line does not return to normal state and the trigger does not return to its original position, it cannot be closed and powered.
low voltage circuit breakers can not only turn normal load current and overload current on and off, but also turn short circuit current on and off. In addition to controlling the circuit, the low voltage circuit breaker also has certain protective functions such as overload, short circuit, undervoltage and leakage protection, etc.
The input and output drawers of the low voltage circuit breaker are rotated clockwise or counterclockwise by the rocker, and the insertion structure is adopted in both the main circuit and the secondary circuit, omitting the insulator required for the fixed type Machine can be used for two purposes. which improves efficiency, facilitates operation and maintenance, and increases safety and reliability. In particular, the main circuit contact holder of the drawer floor can be used together with the fuse contact holder of type NT, so that the fuse can be used directly for power supply in an emergency.
JIELI Electrical has three production sites all over the world, namely in Poyang, Jiangxi, China, Yueqing, Zhejiang, China, and Yangon, Myanmar. The production base has passed the international ISO9000 certification for quality assurance systems.
low voltage circuit breakers are also called automatic air switches or automatic air circuit breakers or short circuit breakers. It is an electrical device that has both manual switching functions and automatic power failure, undervoltage, overload and short circuit protection.
What role do low voltage circuit breakers play?
How does a low voltage circuit breaker work?
What are the components and working methods of low voltage circuit breakers?
1.low voltage circuit breakers are mainly used in low voltage circuits to protect electrical equipment from short circuits, or if the voltage is abnormal or the current is too high, the circuit breaker can avoid some dangerous accidents.
2.The low voltage circuit breaker is very suitable for machine tools as it can take on a variety of protective functions. When the machine tool equipment is working, the low voltage circuit breaker is installed, so it does not need to be started frequently to avoid damage to the associated equipment.
3.There is an alarm contact in the low voltage circuit breaker. When the circuit is overloaded or a short circuit occurs, the alarm contact emits a sound, or a indicator light lights up to remind people in time to avoid major accidents.
The low voltage circuit breaker has great advantages over the knife switch when entering the house. First, it can interrupt a large current and has an arc extinguishing device, which is suitable for increasing the load of the house circuit. In addition, its thermal stability and service life are better than that of the knife switch. The second is that it can automatically interrupt the circuit if an error occurs. There are two triggers in the circuit breaker, one is a thermal bimetal trigger, which is used for overload delay protection; the other is an electromagnetic trigger used for immediate short circuit protection.
After using the circuit breaker, the fuse is no longer installed in the house circuit. When an error occurs, the trigger automatically triggers (commonly known as triggering) to interrupt the circuit. When the error is fixed, it can be reused simply by resealing without replacing parts.
The low voltage circuit breaker consists of three basic components: contact and arc extinguishing system, trigger, transmission and actuation mechanism. The contacts shown in the drawings are closed, and the latch locks this closed state with a hook to stabilize it. In case of overload, the overload trigger responds and the small multiple overload current bends the bimetal slightly after a certain time. The contacts are separated for overload time delay protection. When a short circuit occurs, the short circuit trigger acts, and the multiple short circuit current quickly attracts the anchor by the magnetic force generated by the electromagnet to move it downwards. stable, the contacts are quickly disconnected to achieve immediate short-circuit protection.
JIELI Electrical Engaged in research and development, production and supply chain management of MCB, RCCB and related supporting products.