What are the differences between miniature circuit breakers and molded case circuit breakers

Miniature circuit breaker (hereinafter referred to as MCB) is a circuit breaker switch product with a large range of use and a large number. Its main function is to maintain the power distribution equipment of electrical engineering terminal equipment. Since both belong to isolating switches, plastic case circuit breakers are mainly suitable for small-capacity boots, so it is very practical and important to grasp the difference between the two and choose the right commodity. The key role of plastic case circuit breaker (hereinafter referred to as MCCB) is to maintain load and short-circuit faults in low-voltage power distribution systems and motor protection control circuits. It has become a very common commodity in industry due to its safety and reliability. Here is a brief description.
First, let’s talk about the basic commonalities. Since both are isolating switches, some major product implementation standards need to be followed, and the principles are the same. Then talk about the difference between the two. Generally speaking, there are the following aspects:
1. The main parameters of electrical equipment are different.
2. The main parameters of mechanical equipment are different.
3. The application of the office environment is different.
Also, from a purchasing point of view, there are actually many differences between the two.
Current level
The maximum current level of the plastic case circuit breaker is 2000A. The maximum current level of the miniature circuit breaker is within 125A. Due to the difference in capacity, in actual work, the effective area of ​​the plastic case circuit breaker also exceeds that of the miniature circuit breaker. At the same time, the connected wires are also very thick, which can reach more than 35 square meters, while the miniature circuit breaker is only suitable for connecting transmission lines within 10 square meters. Therefore, in general, larger rooms are more suitable for choosing plastic case circuit breakers, depending on the situation of the room.
Installation method
Plastic case circuit breakers are mainly assembled with screws, which are very easy to get stuck, have good contact and run smoothly. Miniature circuit breakers are mainly mounted on rails, sometimes resulting in poor contact due to insufficient torque. Due to different installation methods, the assembly of plastic case circuit breakers is stronger and less difficult than miniature circuit breakers.
Actual operation and service life.
in actual operation. Molded case circuit breakers are protected by two sets of devices for overcurrent and short circuit respectively. The action value of overcurrent protection can be adjusted manually, which is convenient and quick. The opposite flow and short-circuit fault of the micro-circuit breaker use the same set of equipment, and the current cannot be adjusted, which is often difficult to solve. Molded case circuit breaker has large interphase distance and arc extinguishing cover, which has strong arc extinguishing ability, can withstand high short circuit capacity, is not easy to cause interphase short circuit, and has a longer service life than micro circuit breakers.
Apply coordination skills.
On the one hand, plastic case circuit breakers are more prominent, and their setting coordination ability is stronger than that of miniature circuit breakers. The overvoltage and overcurrent protection devices of the plastic case circuit breaker are separated from each other, and the action value of the overcurrent protection can also be flexibly adjusted. The short-circuit protection and over-current protection of the micro-circuit breaker are unified equipment, and the adjustment and coordination ability is not enough.
Based on the above, it seems that all MCBs are at a disadvantage, but in fact, in some cases, MCBs must be selected. For example, when the safety factor of the route must be improved, due to the high posture sensitivity of the miniature circuit breaker, the breaking action is fast, which is more conducive to the maintenance of the route and household appliances.
Therefore, we can see that both have different advantages and application areas. It is important to fully understand the difference between plastic case circuit breakers and miniature circuit breakers and choose according to your needs.