What Is A Molded Case Circuit Breaker (MCCB)?

08th Feb 2022

A molded case circuit breaker is a form of electrical protection device used in large-scale PV systems. It protects against overload and short circuits, and its adjustable trip settings allow it to work in a variety of voltages and frequencies. 

For these reasons, it has become one of the most popular types of circuit breakers. However, a few characteristics set this type of circuit breaker apart from other types.

A molded case circuit breaker is a device with a molded frame, which is a specialized material used to provide insulated housing for the electrical device. The basic function of a molded case circuit breaker is to safely switch a circuit off and on. They are also often used for overload protection in high-current applications. 

If you want to know more about a molded case circuit breaker (MCCB), continue reading this article. 

What Is A Molded Case Circuit Breaker?

If you are looking for the best circuit breaker for your application, you may be wondering what a molded case is. These breakers can handle high currents. They are made from a special material and are incredibly durable. However, the most important thing to know before selecting a breaker is its interrupt rating. This value should be greater than the fault current that will be drawn from the circuit.

B-frame Square D molded case circuit breakers are high-current interrupters. They interrupt excessive current flows to protect devices from damage due to excessive current flow. They are often used in industrial control panels and commercial OEM applications. These molded-case circuit breakers contain current-carrying parts, mechanisms, and trip devices. These breakers are a good choice for applications where overcurrent protection is necessary.

Another type of molded-case breaker is MCP. This type is used in motor starters. They have the same basic function as MCP breakers but are not UL listed. It does have overload sensing capabilities but is used only in motor-start assemblies. 

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The Operating Mechanism of MCCB

MCCBs (Moulded Case Circuit Breakers) are automatic electrical devices that protect against overload and short circuits. The basic function of an MCCB is to automatically open a circuit if the current exceeds the normal rating. In some cases, the breaker may trip automatically if the current remains excessive for an extended period of time. It is important to understand the proper sizing of your MCCB before installing it.

One of the most important characteristics of a molded case circuit breaker is its insulating housing. They are usually made from a thermoset composite resin or glass-polyester material. This type of material offers ruggedness and high dielectric strength. Different types of molded cases are named for their characteristics. For example, Z-type breakers have lower thresholds and are used in electrical installations that may have sensitive devices.

In addition to the current rating, these breakers also feature adjustable trip settings. You can select between static and electronic release circuit breakers based on the features you want. Microprocessor release circuit breakers are even more versatile and can be set to a higher or lower number of levels. They can be adapted to changing loads and environments. They also allow for a future expansion of the load capacity.

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