DC protection circuit of molded case circuit breaker to prevent short circuit 125a250a350a630A

What is a molded case circuit breaker? What is a frame circuit breaker? Most electrical personnel are probably very familiar with it. But when it comes to the difference and selection between frame circuit breakers and molded case circuit breakers, many electrical personnel may only know one and not know the other, especially for some electrical beginners who are not familiar with it. We all know that molded case circuit breakers are also known as shell circuit breakers. It is a type of terminal that is wrapped in a plastic shell to form an internal connection network. It has a very low discharge resistance and can prevent the device from being affected by moisture or dust in wet environments. The characteristics of this type of circuit breaker are small size, small space occupation, and the ability to release a large amount of current in a short period of time. In addition, molded case circuit breakers also have advantages such as simple installation, low probability of failure, and high reliability.

Frame circuit breaker, also known as universal circuit breaker, is a mechanical switchgear that can connect, carry, and disconnect current under normal circuit conditions, as well as connect, carry, and disconnect current for a certain period of time under specified abnormal circuit conditions. So what is the specific difference between molded case circuit breakers and frame circuit breakers? How to choose between the two? The following article will explain in detail to everyone. After reading the article, I hope to deepen the understanding of molded case circuit breakers and frame circuit breakers for electrical personnel.

Function of molded case circuit breaker

The molded case circuit breaker can automatically cut off the current when the current exceeds the trip setting. Plastic casing refers to the use of plastic insulators as the outer shell of a device, used to isolate conductors and grounded metal parts. Molded case circuit breakers typically contain thermal magnetic trip units, while larger models of molded case circuit breakers are equipped with solid-state trip sensors. Its release unit is divided into: thermal magnetic release and electronic release. The commonly used rated currents are as follows: 16, 25, 30, 40, 50, 63, 80, 100, 125, 160, 200, 225, 250, 315, 350, 400, 500, 630A.

Function of frame circuit breaker

Universal circuit breaker, also known as frame circuit breaker, is a mechanical switchgear that can connect, carry and disconnect current under normal circuit conditions, as well as connect, carry and disconnect current for a certain period of time under specified abnormal circuit conditions. Universal circuit breakers are used to distribute electrical energy and protect lines and power equipment from overload, undervoltage, short circuits, etc.
This type of circuit breaker usually has a steel frame, and all components are installed inside the frame. It has a large capacity and can be equipped with multiple functional release devices and more auxiliary contacts. It has high breaking capacity and thermal stability, so it is commonly used in places that require high breaking capacity and selective protection.