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.
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 miniature circuit breaker is the most widely used terminal protection device in the construction of electrical terminals for power distribution. It is used for single-phase and three-phase short circuit, overload and overvoltage protection under 125 A, including single-pole 1P, two-pole 2P, three-pole 3P and four-pole 4P.
The typical size of the miniature circuit breaker is 18 mm width as module (1 bit, 1 P) and 9 mm as module. Friends should pay attention to their statement when buying to prevent the sizing of the distribution box top. Mistakes. In fact, 9 and 18 can be converted if we use it. Micro-Break has two frame currents 63A and 125A. The 1st position of the microfracture below 63 A is 18 mm, and the 1st position of the 125-frame current is 27 mm.
When a miniature circuit breaker in the distribution box needs to be replaced, it is accidentally jammed in the middle. We can only remove the wire and pull the clip on the bottom of the miniature circuit breaker to separate it from the guide rail. The clip is uncomfortable to pull by hand. Without a slotted screwdriver, it is not easy to lever.
Compact circuit breakers have a current carrying capacity of up to 2000 A. The maximum rated current of miniature circuit breakers is within 125 A.
Due to the capacity difference between the two, in the specific work, the effective area of the Compact circuit breaker is also larger than that of the miniature circuit breaker, and the wires connected to it are also relatively thick, which can reach more than 35 square meters, while the miniature circuit breaker is only suitable for connecting 10-wire below the square. Therefore, in general, for indoor conditions, it is better to choose compact circuit breakers for larger rooms.
When selecting a miniature circuit breaker, the following conditions should be considered:
1) The rated voltage of the miniature circuit breaker should not be less than the rated voltage of the line;
2) The rated current of the miniature circuit breaker and the rated current of the overcurrent trigger are not less than the calculated current of the line;
3) The rated short-circuit switching capacity of the miniature circuit breaker is not less than the maximum short-circuit current in the line;
4) The selection of miniature circuit breakers for power distribution shall take into account the short-term delayed short-circuit on-off capability and the coordination between the delay protection levels;
5) The rated voltage of the miniature circuit breaker's undervoltage trigger is equal to the rated voltage of the line.
JIELI Electrical has been active in the low voltage miniature circuit breaker industry for almost twenty years. Dedicated to research and development, production and supply chain management of MCB, RCCB and related supporting products. It is not only a production service provider solving supply chain problems, but also a manufacturer offering OEM and ODM production services.
low voltage circuit breakers are also called automatic air switches or automatic air circuit breakers. The low voltage circuit breakers sold on the market can not only be switched manually, but also equipped with automatic switching. If a short circuit occurs in the circuit or the current is too high, it can automatically interrupt the circuit and take on a protective function in time.
What is the main structure and function of the low voltage circuit breaker?
What are the main components of the low voltage circuit breaker?
What are the precautions for using low voltage circuit breakers?
1.Accessories for low voltage circuit breakers such as working current trigger, undervoltage trigger, electric drive, etc.; Shunt and undervoltage are voltage coils, as long as the voltage values are the same, they are used for AC systems, not AC systems. It can be used in DC systems without changes. Auxiliary, alarm contacts, AC and DC mass. The electric drive must be redesigned for DC operation.
2.Since the DC current does not have the zero-pass characteristics of alternating current, the interruption of DC short-circuit current (even the residual current with a small multiple); Erasing the arc is difficult, so the wiring should be connected two-pole or three-pole in series. increase the fracture so that each fracture carries part of the arc energy.
3.low voltage circuit breaker In addition to the traditional thermal magnetic trigger, the electronic trigger is also widely used. An important advantage of the electronic trigger is that it can operate stably even with changes in ambient temperature.
The contacts mechanically connected to the opening and closing mechanism of the main circuit of the low voltage circuit breaker are mainly used to indicate the opening and closing state of the circuit breaker, and are connected to the control circuit of the circuit breaker, to implement the opening and closing of the circuit breaker to the associated electrical appliances. Control or locking. For example, output signals on signal lamps, relays, etc.
The working current trigger is a remote-controlled opening accessory. The under voltage trigger is used to automatically disconnect the low voltage circuit breaker to interrupt the power supply when a certain voltage drop in the power supply voltage occurs in the protected circuit, so that the electrical load equipment or electrical equipment below the circuit breaker is protected from under voltage damage.
3. Electric drive
It is an accessory for circuit breakers for automatic opening and closing over long distances. There are two types of electric drives: motor drive and electromagnetic drive.
Since direct current does not have zero-pass characteristics such as alternating current, it is difficult to interrupt the short-circuit current of direct current (even the residual current with a small multiple); It is difficult to extinguish the arc, so the wiring should apply the method of two-pole or three-pole series connection to increase the fracture, so that each fracture carries part of the arc energy.
In addition to the traditional thermal magnetic trigger, the electronic trigger is also widely used. An important advantage of the electronic trigger is that it can operate stably even with changes in ambient temperature.
JIELI Electrical has been active in the low voltage circuit breaker industry for almost twenty years. Dedicated to research and development, production and supply chain management of MCB, RCCB and related supporting products.
The miniature circuit breaker is mainly used for home use and generally only has short-circuit and overload protection. However, it is small in size, low in price, and easy to maintain. It is generally used at home. The maximum cutting capacity does not exceed 10KA.
An MCB or miniature circuit breaker is an electromagnetic device that embodies a complete enclosure in a molded insulating material. The main function of the MCB is to switch the circuit, i.e. automatically turn on the circuit (already connected to it) when the current through it (MCB) exceeds the value it is set to. It can be turned on and off manually like a normal switch if needed.
If it is a C40 type circuit breaker, it is generally suitable for use in home power distribution and lighting circuits, such as for controlling power distribution or lighting connections. If it is a D63 type circuit breaker, it is used to control industrial motors.
If it is a C40 type circuit breaker, its sectional capacity is about 4 to 7 times, while the sectional capacity of a D-type circuit breaker is slightly higher, which can reach between 7 times and 10 times.
The tripping current of the C40 type circuit breaker is 5-10 times the rated current, and the tripping current of the D63 type circuit breaker is 10-14 times the rated current.
Traditional AC miniature circuit breakers are mainly used as short-circuit or over-current protection appliances in power systems with AC 50hz and above. Due to the increasing requirements for power grid security and the rapid development of computer technology in recent years, people have begun to study new intelligent low-voltage switchgear to replace traditional low-voltage circuit breaker products. Among them, intelligent high-voltage vacuum load switch is characterized by its unique function which has been widely used.
With the continuous improvement of industrial automation and the increasing emphasis on environmental protection, people have put forward higher requirements for the reliability and service life of electrical equipment. Therefore, there are many new intelligent components such as miniature circuit breakers and leakage protectors in the intelligent low-voltage power distribution cabinets currently on the market.
JIELI Electrical has three production bases around the world, namely in Poyang, Jiangxi, China, Yueqing, Zhejiang, China, and Yangon, Myanmar. The production base has passed the international ISO9000 quality system certification. Zhejiang's production base is still a local patent demonstration enterprise and high-tech enterprise. Possess an annual production capacity of 20 million PCS for MCB and 1 million PCS for RCCB. The customers served are in nearly 50 countries around the world.
Jieli Electric officially moved its factory in June. The location was moved from Xiangyang Industrial Zone, Liushi Town, Yueqing City, to No. 81, Xiangbei East Road, Yishan Village, Liushi Town, Yueqing City.
The main components of the low voltage circuit breaker are: contacts, triggers, electrical actuators, energy release electromagnets, rotatable actuation handles, extended handles, handle locks, etc.
Which common low voltage circuit breakers do you know?
How to choose a suitable low voltage circuit breaker?
Why do we need to understand low voltage circuit breakers?
Which common low voltage circuit breakers do you know?
1) Current limit switch
A circuit breaker whose shutdown time is short enough to interrupt before the short-circuit current reaches its expected peak value.
2) Plug-in circuit breaker
A circuit breaker equipped with a plug contact (or contact seat) on the terminal to insert the corresponding static contact seat (or contact) and connect it to the external wire.
3) Circuit breakers for removal
It's some kind of pluggable circuit breaker. There is a special circuit breaker support mechanism during plug-in, which can support the circuit breaker even when the inserted contacts are in the separate position, ensuring a safe isolation distance. Drawer circuit breakers should generally have three positions: connect, test and disconnect.
4) Circuit breaker with fuse
A single electrical device consisting of a circuit breaker and a fuse, each phase being formed in series by a fuse and a pole of the circuit breaker.
5) With self-retaining circuit breaker against switching on
A circuit breaker in which the movable contacts do not conduct current, even if a command to close is given, if the conditions that caused the opening process persist.
6) Open circuit breaker
A circuit breaker that opens and closes in the open air
There are also many models of low voltage circuit breakers on the market. For example, there are dz47, which are small circuit breakers, and z20, including dw15 and so on. Different models have different applications.
When choosing, we should decide according to the current load capacity in the circuit, which type of circuit breaker to choose. You must not choose the wrong one, otherwise the circuit breaker will not play a protective role, but it will pose certain safety risks to our power consumption.
When it comes to the technical parameters of low voltage circuit breakers, most electrical professionals need to be very clear, but when it comes to the importance of the parameters of low voltage circuit breakers, many electrical professionals can be confused. low voltage circuit breakers are an important component of low voltage electrical products in the energy industry. With the further improvement of the degree of automation, the performance and service life requirements of circuit breakers are getting higher and higher, and the reliability of circuit breakers is mainly determined by their actuation mechanism. Reliability. Therefore, it is of great importance and practical value to investigate the reliability and optimal design technology of the low voltage circuit breaker drive.
JIELI Electrical has been active in the low voltage circuit breaker industry for almost twenty years. JIELI Electrical Engaged in research and development, production and supply chain management of MCB, RCCB and related supporting products.
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).
JIELI Electrical has the production base that has passed the international certification of ISO9000 quality system. Zhejiang's production base is still a local patent demonstration enterprise and high-tech enterprise.