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Most miniature circuit breakers are frame structures, and some are assembled with discrete components. Working principle The AC operating power is rectified to obtain DC power to supply the exciter winding of the main contact coil of the miniature power switch for excitation operation; at the same time, the rotor of the miniature motor rotates through the transmission mechanism to drive the anchor, move up and down along the slip ring to close the contacts;
If the load is short-circuited or heavily overloaded, the miniature motor immediately stops rotating; When the load is restored, the miniature motor continues to work.
The miniature circuit breaker uses the thermal expansion of the bimetal sheet to bend the release lever so that the miniature circuit breaker triggers and plays the role of overload protection. There will be a certain time difference in overload protection. When a short circuit occurs, the current flows through the induction coil to create a strong magnetic field that pushes the lever to quickly trigger the miniature circuit breaker.
According to the various protection functions, the trigger can be divided into overcurrent trigger and power failure trigger.
If the line is generally overloaded, although the overload current cannot make the electromagnetic trigger work, the heating element can generate a certain amount of heat, causing the bimetal sheet to bend upwards during heating. Press the lever to release the hook and latch and release the main contact. The head is disconnected and the power supply is cut off.
The current maximum current of the miniature circuit breaker is 125A. Depending on the protection class, it is divided into B, C and D types, and according to the number of poles, it is divided into 1, 2, 3 and 4-poles, which are all models with leakage protection.
compact circuit breakers currently have a maximum current of 1600 A and a maximum rated voltage of 690 V. Depending on the ignition protection type, it is divided into distribution protection and motor protection; according to the number of poles, it is generally divided into 2, 3 and 4 poles; Models with leakage protection The current is below 630A.
JIELI Electrical has been focusing on the development and production of miniature circuit breakers for several years. And it is committed to providing perfect service to every customer from all over the world.
low voltage circuit breakers are widely used in low voltage power distribution systems at all levels, to control the power of various mechanical devices, and to control and protect power connections.
Why are low voltage circuit breakers often used in series with low voltage fuses?
What is the function of the contacts of the low voltage circuit breaker?
How is the short-circuit protection of the low-voltage circuit breaker performed?
There are two reasons for this:
1.The role of low voltage circuit breakers is often used to interrupt the main power supply without the effect of current overload.
2.The role of low voltage fuses in the circuit means that the fuse will burst when the current in the circuit is overloaded.
The low voltage circuit breaker is commonly known as "air circuit breaker". Its main function is: It can connect short circuit with load and interrupt, and at the same time has overload and short circuit protection. In addition, additional accessories (e.g. leak protection accessories, undervoltage trigger accessories, working current trigger accessories, etc.) can be added to realize leakage protection, undervoltage protection, overvoltage protection, remote control and other functions.
What is the function of the contacts of the low voltage circuit breaker?
Contacts mechanically connected to the opening and closing mechanism of the circuit breaker's main circuit are mainly used to indicate the opening and closing status of the circuit breaker, and are connected to the circuit breaker's control circuit, to control the associated electrics devices by opening and closing the circuit breaker. or lock. For example, output signals to signal lamps, relays, etc. The universal circuit breaker has six pairs of contacts (three closers, three openers), the DW45 has eight pairs of contacts (four closers, four openers). The low voltage circuit breaker has a frame rated current of 100 A for a switching contact with an interruption point and 225 A, and more is a bridge contact structure. Normally closed, the conventional heating current is 6A. The number of switching games is equal to the total number of switching games of the circuit breaker.
Alarm contact for low voltage circuit breaker failure, and this contact only works when the circuit breaker triggers and interrupts, mainly used for free triggering, when the load of the circuit breaker is overloaded, short-circuited or under voltage, etc. Convert from original normally open position to closed position, turn on the indicator lights or bells, buzzer, etc. in the auxiliary circuit to indicate or remind the fault triggering state of the circuit breaker. Since the probability of the circuit breaker triggering freely due to a load failure is not too great, the life of the alarm contact is 1/10 the life of the circuit breaker. The working current of the alarm contact generally does not exceed 1A.
The short circuit protection of the thermal electromagnetic AC circuit breaker adopts the magnetic system used for the filtered rectifier circuit (DC), and the set current value of the original AC must be multiplied by the factor 1.3. The short circuit protection of the fully electromagnetic type is the same as that of the thermal electromagnetic type.
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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.
Features:
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.
Effect:
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.
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.
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.
1. Contact
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.
2. Release
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 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.
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.
A low voltage circuit breaker is a switching device that can not only turn normal load current and overload current on and off, but also can turn short circuit current on and off. In addition to the control function in the circuit, the low voltage circuit breaker also has a certain protective function.
What is the protective function of the low voltage circuit breaker?
What is the plug wiring for low voltage circuit breakers?
What is the key structure of the low voltage circuit breaker?
Protection functions of low voltage circuit breakers: short circuit protection, overload protection and undervoltage protection.
low voltage circuit breakers were formerly referred to as automatic switches or air switches. In addition to full load shutdown capability, it also has functions such as short circuit protection, overload protection and undervoltage protection, and has good arc extinguishing ability. It is often used as a main switch or secondary circuit switch in the distribution box. low voltage circuit breakers should not be operated frequently and are suitable as control units in lighting distribution boxes or other rare operations.
On the mounting plate of the complete set, first install a circuit breaker mounting seat, on the mounting seat there are 6 connectors, and on the connecting plate of the circuit breaker there are 6 sockets. There is a connecting plate on the surface of the mounting seat or bolt behind the mounting seat, and the power line and load line are pre-connected to the mounting seat. Insert the circuit breaker directly into the bracket for use. If the low voltage circuit breaker is defective, just pull out the bad one and replace it with a good one. Its replacement time is shorter and more convenient than the wiring before and after the board. Because plugging in and out requires a certain amount of manpower. This saves maintenance and replacement time. When installing a pluggable circuit breaker, check that the circuit breaker plug is firmly depressed and securely fasten the circuit breaker to reduce contact resistance and improve reliability.
1. Energy-releasing electromagnet
When the user presses the button after the electromagnet coil is excited, the electromagnet is closed to release the energy storage spring, and the circuit breaker is closed.
2. Turn the handle
The operator rotates the handle outside the door clockwise or counterclockwise to ensure the circuit breaker closes or opens. At the same time, turning the handle can ensure that the cabinet door cannot be opened when the circuit breaker is closed; only when the handle is opened or buckled, the door of the control cabinet can be opened. In an emergency, when the circuit breaker is "on" and the door needs to be opened, the red release button can be pressed on the side of the rotary handle base.
JIELI Electrical has three production sites all over the world, namely in Poyang, Jiangxi, China, Yueqing, Zhejiang, China, and Yangon, Myanmar. Own an annual production capacity of 20 million PCS for MCB and 1 million PCS for RCCB. Our clients are located in almost 50-countries around the world.