Circuit breakers play an important role in protecting your electrical circuits from faults and overloads. But with so many options to choose from, you might find yourself struggling to determine which one suits your needs best. In this guide, we take a look at the molded case circuit breaker (MCCB), break down its intricacies and help you understand when and how to use it. Read on to find out all about this type of breaker and its unique benefits.
Understanding Molded Case Circuit Breakers
A circuit breaker refers to a protective device in an electrical circuit that detects short circuits and overloads and prevents potential damage by cutting off power supply. These come in a variety of designs and carrying capacities, making the different options available suitable for specific areas of application.
Among the different categories are MCCBs and conventional breakers. MCCBs are a specialized type of breaker designed for use predominantly in commercial and industrial settings. Let us take a closer look how they work and the unique features that differentiate them from traditional models.
How They Work
An MCCB consists of a molded plastic case that encloses all internal components, protecting them against environmental factors and providing electrical insulation. To protect electric circuits, this device uses two main detection mechanisms, thermal and magnetic.
- Thermal Mechanism: This mechanism focuses on the prevention of long-term overload conditions. It uses a bimetallic strip that bends when exposed to prolonged heat resulting from an electrical overload. Once it bends to its limit, it automatically trips the circuit, interrupting power supply to protect the wires from overheating and potentially catching fire.
- Magnetic Mechanism: This mechanism offers protection against short-circuiting. An electromagnetic component in the device consists of a movable iron core and a coil. If a short-circuit occurs, there’s typically a strong surge in current, which creates a strong magnetic field in the coil, pulling the core. This triggers the tripping mechanism, breaking the circuit almost instantaneously.
After a tripping event, you can manually reset the MCCB by switching it on when you resolve the root cause of the problem. This makes it possible to keep reusing the breaker even when faults occur, unlike an electric fuse which has to be replaced when it blows up.
Unique Features of MCCBs
- Robust, Molded Case: This type of circuit breaker derives its name from its unique case. Unlike traditional breakers, MCCBs come with a robust case, designed to withstand the harsh environments common in certain industrial and commercial settings. In addition to protecting the internal components, the molded case is also designed to dissipate heat, thus keeping the device cool.
- High Carrying Capacity: Another outstanding feature is its ability to withstand high fault currents without breaking down. You can choose from a wide range of ratings, ranging from 30A all the way to 6,000A and even higher. This high breaking capacity is ideal for industrial applications where high energy levels are common.
- Trip Characteristics: MCCBs offer varying trip characteristics such as adjustable, short-time delay, long-time delay, and instantaneous trip. These varying settings give them a high level of versatility.
- Applications: They are also versatile when it comes to the range of applications that they can handle. In addition to providing protection from overloads, they offer ground fault protection and protection from motor overload. You can also use them for three-phase and single-phase systems.
Choosing the Right Circuit Breaker from Essential Electric Supply
Essential Electric Supply carries a comprehensive portfolio of high-quality electric parts, including circuit breakers and more. Whether you require a molded case circuit breaker or a conventional one, we have a variety of options to choose from to suit your unique needs. Our highly knowledgeable and friendly team is always on hand to help you find the precise part you are looking for.
