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.
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.
1) Type:
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.
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.
The miniature circuit breaker is installed on the interrupted distribution line to effectively protect the line and electrical equipment and avoid overload operation, resulting in certain safety risks to the line and electrical equipment. From this point of view, miniature circuit breakers have a high application value, and it makes sense to actively research and develop miniature circuit breakers. For more information about information about miniature circuit breaker, please read the following words.
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.
What role do low voltage circuit breakers play?
What are the relevant parameters of low voltage circuit breakers?
What types of low voltage circuit breakers are there?
low voltage circuit breakers refer to mechanical switching electrical appliances that can connect, charge and disconnect current under normal circuit conditions and can be connected, charged and disconnected for a specified period of time under certain abnormal circuit conditions. Perform switching operations on power distribution circuits, motors or other electrical equipment to perform a protective function according to the specified conditions. In other words, it is a switch that can automatically interrupt the circuit if overload, short circuit or undervoltage occurs during the flickering of the circuit.
low voltage circuit breakers are used to distribute current, prevent the frequent operation of asynchronous motors, power lines and motors, etc. protect and automatically shut off circuits in case of major overloads, short circuits, undervoltages and other errors and combine fuse load switches and overheating relays. In addition, no parts need to be replaced after the residual current is interrupted. It's widespread now.
1.The model of low voltage circuit breaker is generally composed of text symbols and numbers according to the national technical standards as follows:
2.The letter number of the product is represented by the following letters. s%)fewer oil switches; d. circuit breakers for more oil k. circuit breakers for air L. circuit breakers for sulfur hexafluoride; Z. Vacuum circuit breakers; Q. Gas generator circuit breaker; C. Arc deflection circuit breaker.
3. Installation location code; n---inside, w---outside.
4. serial number of the design series; represented by points 1, 2, 3.
5. Rated voltage, KV.
6.Other supplementary work characteristics identification, G-enhanced, F-phase separated operation.
7. Rated current, A.
8. Rated switching current, KA.
9. Special environment code. Fingers empty like DZ47-63. DZ47LE-63 with leakage. C16: refers to the current of 16A. Residents of normal households use C10-16, and the construction uses C32 or higher.
1) (Mechanical) circuit breaker
A mechanical switchgear capable of generating, conducting and interrupting current under normal circuit conditions and capable of generating, conducting, conducting and interrupting current even under certain abnormal circuit conditions (e.g., short circuit). Formerly known as: Automatic Switch
2) Universal circuit breaker
A circuit breaker that integrates all components with a frame structure base with insulating pads and has various structural changes and uses.
Formerly known as: Frame Type Automatic Switch
3) circuit breaker with plastic housing
A circuit breaker with a housing made of molded insulating material and all components assembled in one. Synonym: compact circuit breakers
Formerly known as: Automatic switch with plastic housing
JIELI Electrical not only has a production service provider solving supply chain problems, but also a manufacturer offering OEM and ODM production services.
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 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.
MCB is a miniature circuit breaker, while RCB is a circuit breaker with residual current protection. Different loads should use different types of circuit breakers.
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.
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.
