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.
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.
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.
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.
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 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 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.
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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