Indoor and outdoor high-voltage vacuum circuit breaker
Circuit breaker is composed of a contact system, an arc system, an operating mechanism, a trip unit, a casing, etc. It refers to a switching device that can close, carry and break the current under normal circuit conditions, making the circuit safer. So what are the types of circuit breakers described by the manufacturer of indoor and outdoor high-voltage vacuum circuit breakers? What are the classifications and related functions of circuit breakers? Let's take a look at the relevant knowledge.
1. What are the types of circuit breakers?
(1) Distribution type circuit breaker: Distribution type circuit breaker is divided into the non-selective type and selective type. The non-selective type has only the second-stage protection of overload long-time delay and short-circuits instantaneous, while the selective type means that the circuit breaker has three-stage protection characteristics of overload long-time delay, short-circuit short-delay, and short-circuit instantaneously.
(2) Motor protection circuit breaker: as long as there are two-stage protection types with overload long-time delay and short-circuit instantaneously.
(3) Household and similar household protection circuit breakers are small Class A circuit breakers.
Circuit breaker classification
(1) Universal circuit breaker
The air circuit breaker itself is a kind of circuit breaker, which is another name for the frame circuit breaker (universal circuit breaker). It cannot be said which circuit breakers are included; commonly used air circuit breakers include miniature circuit breakers (air switches), molded case (device type) air circuit breakers, and universal (frame type) air circuit breakers. Generally speaking, the commonly known air circuit breaker refers to the frame type (universal type) circuit breaker.
ACB air circuit breaker, also called frame circuit breaker, the air is used as the arc extinguishing medium, which can break the fault current; VCB: vacuum circuit breaker, vacuum arc extinguishing, can break the fault current;
(2) Plastic case circuit breaker
Manufacturers of indoor and outdoor high-voltage vacuum circuit breakers tell you that MCCB (molded case circuit breaker) plastic case circuit breaker uses air as the arc extinguishing medium and can break the fault current;
(3) MCB miniature circuit breaker
As the arc extinguishing medium, air can break the fault current;
Vacuum isolating switch, used for isolating fractures, cannot break load current and fault current;
When choosing MCB, MCCB, ACB, and VCB, mainly from the safety performance, and related to the load, according to different use requirements, a reasonable choice is to make the best use of everything, to avoid waste. For example, a large-capacity motor needs to use MCCB. The main reason is that the motor needs high-demand protection such as overload, over-current, and quick-break protection, and MCCB can meet its requirements;
For MCB, in general, those with small current (generally 1~63A) and low breaking capacity requirements can be selected, such as lighting, sockets, small-capacity motors (including loads using motors, such as fans, small water pumps, etc.);
MCCB is mainly aimed at loads with large current (generally 50A~630A), high breaking requirements, and precise protection, such as Schneider's NSX series, whose breaking capacity is divided into N and H types; also in some cases, 50A MCB can also be selected, depending on the load;
ACB, generally selected for high currents above 630A, is mainly used as the main circuit breaker of a system, such as the main circuit breaker of the low-voltage section of the transformer. Because of the requirement of breaking capacity, and when a large current fails, the fault current is very large, and MCCB is easy to cause accidents and injuries;
In addition, there are many kinds of protection units in ACB, and different protection units can be configured according to different needs, so as to make the best use of everything and avoid waste. However, the performance of ACB configured with the most basic protection unit is similar to that of MCCB, and it is not as good as MCCB in terms of cost performance. After all, the price of ACB is high. Also in some cases, MCCB also has a large capacity (such as Schneider 800A), depending on the load;
Warm reminder from manufacturers of indoor and outdoor high voltage vacuum circuit breakers, VCB is mainly used in medium voltage systems as system protection. The difference between ACB and VCB is that the arc extinguishing medium is different, and its arc extinguishing performance is also different. There are also SF6 circuit breakers, which are filled with sulfur hexafluoride as the arc medium. The effect is also very different, and the difference is quite large, you can refer to the relevant information.
The scope of use of circuit breakers
(1) High voltage circuit breaker
It can not only cut off or close the no-load current and load current in the high-voltage circuit but also cut off the overload current and short-circuit current through the function of the relay protection device when the system fails. ability.
(2) Low voltage circuit breaker
It is a switching device that can not only switch on and off normal load current and overload current, but also switch on and off short-circuit current.
There are many classification methods for low-voltage circuit breakers. According to the category of use, there is a selective type (the parameters of the protection device can be adjusted) and a non-selective type (the parameters of the protection device cannot be adjusted). According to the arc extinguishing medium, there are air types and vacuum types.
The basic structure of a vacuum circuit breaker interrupter is composed of an airtight insulating shell, conductive circuit, shielding system, contacts, bellows, and other parts. Ceramic shell vacuum interrupter. It can be used for the protection and control of electrical equipment in industrial and mining enterprises, power plants, and substations. It is especially suitable for places that require no oil, less maintenance, and frequent operations. The circuit breaker can be configured in central cabinets, double-layer cabinets and In the fixed cabinet, it is used to control and protect high-voltage electrical equipment.
The above content is the circuit breaker shared by the indoor and outdoor high-voltage vacuum circuit breaker manufacturer and everyone. This article has made a super detailed introduction to these contents.