What are the characteristics of miniature circuit breakers?

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.

What are the characteristics of miniature circuit breakers?

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.

What is a miniature circuit breaker and what is the difference between a compact circuit breaker and miniature circuit breaker?

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.

How to choose the right miniature circuit breaker?

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.