1. Frame circuit breaker (universal type) - ACB:
Rated current: In principle, frame circuit breakers are required for rated currents above 630A, and molded case circuit breakers are generally below 630A. It can be seen that the rated current of the frame circuit breaker is much larger, generally 630A-6300A. In addition, in terms of segmentation capacity, frame circuit breakers are higher than molded case circuit breakers.
In practical applications, frame circuit breakers should be used for circuits above 800A or circuits with particularly high segmentation capacity requirements or circuits requiring more functions, and molded case circuit breakers are generally used for circuits below 630A.
For example, ABB's Emax2 series air circuit breakers are divided into four shell levels, namely: 630-1600A, 1600-2500A, 3200-4000A, 4000-6300A model series. The current level and breaking capacity of the frame circuit breaker are higher than those of the molded case, and it is generally used for the upper inlet line, and the molded case is used for the lower stage of the frame.
All parts of the frame circuit breaker are installed in an insulated metal frame, which is often open, and can be equipped with a variety of accessories, and it is more convenient to replace contacts and components, and is mostly used in the main switch at the power end. There are several types of overcurrent trippers, such as electromagnetic, electronic and intelligent trippers. The circuit breaker has four stages of protection: long delay, short delay, instantaneous and ground fault, and the setting value of each protection is adjusted within a certain range according to its shell level. With the development of microelectronic technology, some intelligent circuit breakers have the function of regional selection interlock, which fully guarantees the sensitivity and selectivity of the action.
2. MCCB - MCCB:
It can automatically cut off the current after the current exceeds the trip setting. Molded case circuit breakers usually contain a thermomagnetic trip unit, while larger molded case circuit breakers are equipped with a solid-state trip sensor. Its tripping unit is divided into: thermomagnetic tripping and electronic tripping. Also known as device circuit breakers, they are housed in a plastic enclosure because the ground wire terminal outer contacts, arc extinguishers, trippers, and operating mechanisms are housed in a plastic housing. Auxiliary contacts, undervoltage trippers and shunt trippers are mostly modular, very compact in structure, generally do not consider maintenance, and are suitable for protection switches used as branches. It is mostly operated manually, and electric opening and closing can be selected for large capacity. Due to the application of electronic overcurrent trippers, they can be divided into two types: Class A and Class B, Class B has good three-stage protection characteristics, but due to price factors, Class A products with thermomagnetic trippers have a higher market share.
The molded case circuit breaker is an overcurrent tripper with electromagnetic and electronic types, the general electromagnetic molded case circuit breaker is a non-selective circuit breaker, with only two protection modes: long delay and instantaneous, and the electronic molded case circuit breaker has four protection functions: long delay, short delay, instantaneous and grounding fault. Some of the new products of electronic molded case circuit breakers also have a region-selective interlocking function.
3. Miniature circuit breaker - MCB:
Abbreviated as MCB (Micro Circiut Breaker), it is the most widely used terminal protection appliance in the introduction of building electrical terminal power distribution devices. It is used for single-phase and three-phase short-circuit, overload, over-voltage and other protection below 125A, including single-pole 1P, two-pole 2P, three-pole 3P, four-pole 4P, etc. In the design of civil buildings, the low-voltage circuit breaker is mainly used for the protection and operation of the overload, short circuit, overcurrent, loss of voltage, undervoltage, grounding, leakage, automatic switching of dual power supply and infrequent start of the motor (9 kinds), and the selection of circuit breaker should also consider the selective cooperation between the circuit breaker and the circuit breaker, the circuit breaker and the fuse.
4. Leakage circuit breaker - RCBO:
Leakage protection circuit breaker is a kind of residual current protection electrical appliances, referred to as leakage switch (leakage circuit breaker), the rated current is mostly below 63A, and the leakage switch above 100A is made of air circuit breaker and leakage relay, and there are also leakage protection accessories installed on the plastic shell circuit breaker, the main requirement for it is high action sensitivity and short disconnection time, so as to ensure personal safety and prevent leakage and fire.
The difference between the above types of circuit breakers:
The main differences between ACB-universal (frame) circuit breaker, MCCB-molded case circuit breaker, MCB-miniature circuit breaker, RCBO-leakage circuit breaker are:
(1) The breaking capacity of ACB is relatively high, followed by MCCB, and MCB is the worst.
(2) The installation position is different, ACB is mostly used as the main circuit breaker (power supply end main switch), because it itself has a delay function, can delay breaking and tripping, and also has a good communication function and selectivity, while MCCB is mostly used as a power distribution appliance, in the middle of the line, because it only has the ability to break and reverse the time limit tripping ability, does not have selectivity, and can only be used as a subordinate protection switch; MCB is mostly used on the load side because its breaking capacity is relatively low, generally 6000A and 10000A
(3) The external dimensions are also very different, the volume of MCB is small, easy to install, the volume of ACB is the largest, the installation is complicated, and the MCCB is in the middle.
5. Dual power transfer switch:
According to the IEC-60947-6 international standard, automatic transfer switch appliances can be divided into two levels: PC class or CB class:
PC grade: ATSE that can be turned on and carried, but not used to break short-circuit current. The body can only be used as an automatic transfer switch, and does not have overload and short circuit and other protection functions. The common structural forms include contactor type, load switch type, and single-pole double-throw type.
Class CB: ATSE with an overcurrent tripper whose main contact is capable of switching on and off short-circuit currents. In addition to being used as an automatic transfer switch, the body also has overload, short circuit, and other protection functions, so as to realize two or three stages of load protection and other protection functions. The actuators are usually two circuit breakers.
|
More on that
|
Tianyi switch - the reason why the air switch trips and cannot be pushed
1. What is the reason why the empty trip cannot be pushed?
1. If the air opening itself is faulty or damaged, the air opening should be replaced with a new one.
2. If the line is caused by a short circuit, the line should be found first, and then reconnected.
|
|
Tianyi switch - analysis of wiring questions and answers of button switches
1. How to wire the button switch with a light, there are a total of five binding posts on the button, and now you can only measure how to connect the power cord, but the light is on and I don't know how to connect.
Answer: This situation is relatively simple, this kind of switch should be two terminals connected to the lamp, the other 3 terminals are switches, find out ...
|
|
VTeam switch – how to operate a linear DC power supply correctly
1) Voltage Setting: Turn on the DC switch, adjust the voltage knob to adjust the voltage reading to the desired operating power connection. If you need to lower the voltage, turn the potentiometer slowly so that the drip rate of the voltmeter is compatible with the speed of the manual adjustment knob.
2) Constant Current Setting: Connect ...
|
|
Tianyi switch - precautions for switching power supply to regulate current
1. Pay attention to stability
When adjusting the output current of the switching power supply, the stability of the circuit must be ensured, otherwise there will be current fluctuations, disturbances and other phenomena, which will affect the normal operation of electronic equipment. Therefore, it is necessary to perform a ...
|
|
Tianyi switch - the characteristics and classification of load isolation switch
First, the characteristics of the load switch
A load switch is a switchgear between a circuit breaker and an isolation switch. It has a simple arc extinguishing device, which can cut off the rated load current and a certain overload current, but cannot cut off the short-circuit current
Second, the classification of load switches
According to the operating voltage ...
|
|
Tianyi switch - the role of the travel switch (limit switch) and its working principle
The scope of use of the travel switch (limit switch).
The range of use of travel switches (limit switches) is very wide, so what is the effect of travel switches (limit switches)? The position switch (limit switch) refers to the maintenance of the micro switch from external forces, oil, water, gas, ...
|
|
Tianyi switch - dual power supply automatic transfer switch normal working conditions
1) Ambient air temperature: The upper limit of ambient air temperature is +40°C, the lower limit of ambient air temperature is -5°C, and the average value of ambient air temperature for 24h does not exceed +35°C
2) Altitude: The altitude of the installation site does not exceed 2000m.
3) Atmospheric conditions: Atmospheric relative humidity in the surrounding air ...
|
|
Tianyi switch - switching power supply failure and maintenance method
1. No output, the fuse is normal This phenomenon indicates that the switching power supply is not working or has entered the protection state. First of all, it is necessary to measure whether the starting pin of the power control chip has a starting voltage, if there is no starting voltage or the starting voltage is too low, it is necessary to check whether the starting resistance and the external components of the starting pin are ...
|
|
Tianyi switch - the difference between air switch and leakage protection switch
1. Differences in appearance
Although these two types of switches seem to be very familiar, but there are still differences, half of the leakage protection switch is the same as the air switch, and the other half is not, it is equipped with a test jump button and a recovery button, which are not available in the air switch.
2 ...
|
|
Tianyi switch - what are the differences between limit switches and proximity switches?
First, the characteristics are different
1. Limit switch: The limit switch has the characteristics of small size, multiple functions, high precision, adjustable limit, strong versatility and easy maintenance, installation and adjustment.
2. Proximity switch: The proximity switch has the characteristics of a limit switch, and at the same time has the sensing performance.
|
|
Tianyi switch - PCB design considerations for switching power supplies
In the design of switching power supply, the physical design of the PCB board must be proper, otherwise it may cause excessive electromagnetic interference and lead to unstable power supply.
1. The design process from the schematic diagram to the PCB should be rigorous and perfect: the establishment of component parameters ...
|
|
Tianyi switch - the classification of dual power transfer switches
It is mainly divided into ATS and STS.
STS static toggle switch
STS (Static Transfer Switch), also known as static transfer switch. The STS automatically switches to the second channel to supply power to the load after the first channel fails.
|
|
Tianyi switch - common faults and troubleshooting methods of low-voltage switches
1 The contact is overheated
Contact heat is mainly caused by the current flowing through the contact, and there is power loss between the contacts (such as contact resistance loss, arc energy loss). It is normal for the contacts to heat up, but severe heat (overheating) is a malfunction.
The main ...
|
|
Tianyi switch - the switching mode of dual power transfer switch
Conversion conditions: The purpose of requiring dual power supplies is to complete the automatic and reliable conversion of dual power supplies under "specific" circumstances. This "specific condition" is the conversion premise of the dual power supply, or the conversion condition, which is the primary consideration for choosing the dual power supply.
A. In the event of a power failure ...
|
|
Tianyi switch - the role of low-voltage isolation switch
1. Through the isolation switch, it plays a good insulating role, so that the whole circuit can be safe and secure, and the maintenance personnel or staff also have enough ability to repair the circuit.
2. At the same time, the low-voltage isolation switch can also change the operation mode of the circuit, which is used in the power plant or gas plant.
|
|
Tianyi switch - precautions for high-voltage load switch
1. For vertical installation, the switch frame, closing mechanism, cable sheath, and protective steel pipe should be reliably grounded (not connected in series).
2. Before operation, several no-load opening and closing operations should be carried out, and each rotating part should be free of jamming, closing in place, and there should be enough safety distance after opening.
...
|
|
Tianyi switch - introduction to the characteristics of high-voltage load switch
1. It can isolate the power supply, have obvious disconnection points, and is mostly used for fixed high-voltage equipment.
2. It has an arc extinguishing device and a certain opening and closing speed, and can pass the normal working current and the specified short-circuit circuit in the closing state.
3. It is strictly forbidden to turn on and off the circuit with load.
|
|
What should be paid attention to in the design of Tianyi switch - switching power supply?
1. Wiring
The design requirements of wiring are very strict in the design of switching power supplies, and they must be done well to pass the test. If the designer does not handle the wiring work in the early stage of design, there will be great safety hazards in the future electricity consumption. So here I recommend you to buy a switching electric ...
|
|
Tianyi switch - the operation precautions of the disconnector switch
(1) Before operation, check that the circuit breaker (switch) is in the opening position accordingly to prevent the isolation switch from being pulled and closed with load.
(2) There is a locking device to prevent misoperation between the knife switch, the grounding knife switch and the switch, and the reverse operation must be carried out in order. If it is locked and cannot be operated, ...
|
|
Tianyi switch - the air switch is always the reason for tripping
1. The current value of the air switch is too low, and the load power is greater than the rated power of the air switch.
2. The load joint is not firm, and the joint is not compressed.
3. If there is a short circuit in the line, check whether the electrical plug is dry.
4. The line is aging and leaking, resulting in both the live wire and the neutral line.
|
|
Contact
working hours
