MCCBs

Moulded Case Circuit Breakers (MCCBs) are protective devices used to interrupt and protect electrical circuits from overcurrent and short-circuits. MCCBs are electrical devices that can be used to protect a wide range of electrical systems and equipment.

They are commonly used in low and medium-voltage applications and can handle higher levels of current than Miniature Circuit Breakers (MCBs). MCCBs typically have a rated current of 10 amps to 2,500 amps, and a breaking capacity of up to 200 kA.

Types of Moulded Case Circuit Breakers

Moulded case circuit breakers are available in various configurations to suit diverse electrical protection needs, often categorised by their current handling capabilities and specific functionalities.

MCCB Switch vs. Standard Moulded Circuit Breakers

While both have a similar moulded case breaker design, their functions differ. A standard moulded circuit breaker, for instance, automatically interrupts circuits during faults, providing overcurrent and short-circuit protection. An MCCB switch, however, mainly serves as a manual isolator without automatic tripping.

Based on Current Rating: 100A MCCB, 400A MCCB

The current rating of a moulded case circuit breaker is a critical factor. For lower current circuits, a 100A MCCB may be suitable. For higher demands, like industrial machinery, a 400A MCCB offers the necessary protection against overcurrents and short circuits.

100A MCCB

100A MCCBs are typically used in residential and light commercial settings to provide robust protection for circuits with moderate current demands. These moulded case circuit breakers offer reliable overcurrent and short-circuit protection for distribution boards, lighting circuits, and smaller machinery. Additionally, their key features often include adjustable trip settings, allowing for customisation based on the specific application. Their compact design also makes them suitable for installations where space may be limited, ensuring safety and preventing electrical faults within the specified current capacity.

400A MCCB

400A MCCBs are essential for industrial and high-load commercial environments, providing critical protection for substantial electrical systems and equipment. These moulded case circuit breakers are designed to handle significant current, offering features such as adjustable trip settings to fine-tune protection parameters. Also, their high breaking capacity ensures they can safely interrupt large fault currents, while their robust construction guarantees reliable performance in demanding applications like protecting large motors, transformers, and main distribution boards.

Benefits of Using MCCBs

Moulded case circuit breakers offer numerous advantages for electrical systems, ensuring both safety and operational efficiency.

Reliable Overcurrent Protection

MCCBs provide dependable protection against overcurrents and short circuits, safeguarding equipment and preventing potential electrical hazards. This automatic interruption capability is crucial for maintaining the integrity of electrical installations.

High Durability and Robustness

Designed for demanding applications, moulded case breakers boast high durability and a robust construction, ensuring a long operational lifespan and reliable performance even in challenging environments.

Wide Application Range

From residential and commercial buildings to industrial plants and data centres, MCCBs offer a versatile solution for protecting a broad spectrum of electrical systems and equipment, including motors and transformers.

Adjustable Protection Settings

Many MCCBs feature adjustable trip settings, allowing for customisation of the protection characteristics to match the specific requirements of the application, enhancing both safety and operational flexibility.

Enhanced Safety and Compliance

Utilising moulded case circuit breakers ensures compliance with safety standards, contributing to a safer electrical environment and providing peace of mind regarding the protection of personnel and equipment.

Difference Between an MCB and an MCCB

MCBs are miniature circuit breakers designed to protect low-current circuits up to 125 amps. They typically have a breaking capacity of up to 10 kA and are designed to trip quickly in the event of a short circuit or overload. MCBs are commonly used in residential and commercial buildings to protect individual circuits, such as lighting and power circuits.

MCCBs, on the other hand, are designed to handle higher levels of current (depending on which current rating you buy) and can protect larger electrical systems and equipment. They also have a higher breaking capacity than MCBs.

How MCCBs Work

An MCCB consists of a current-carrying bimetallic strip, a magnetic trip element, and a mechanical latching mechanism. When the current flowing through the MCCB exceeds the set limit, the bimetallic strip heats up and bends, causing the latch to release and trip the breaker. The magnetic trip element senses the magnetic field produced by a high fault current and trips the breaker.

Applications of MCCBs

MCCBs are commonly used in a wide range of applications, including:

• Industrial pPlants: MCCBs are used to protect motors, transformers, and other equipment in industrial plants.
• Data Ccentres: MCCBs are used to protect power distribution systems in data centres.
• Commercial Bbuildings: MCCBs are used to protect lighting and power circuits in commercial buildings.
• Hospitals: MCCBs are used to protect critical equipment in hospitals, such as MRI machines and X-ray machines.

How to Choose the Right MCCB

Selecting the appropriate moulded case circuit breaker involves careful consideration of your specific electrical system requirements. Key factors to consider include:

• Load Requirements: Accurately assess the current demands of the circuit to ensure the MCCB's current rating is suitable.
• Trip Characteristics: Understand the required trip characteristics (e.g., thermal-magnetic) for effective protection against both overloads and short circuits.
• Voltage Rating: Verify that the moulded case circuit breaker's voltage rating meets or exceeds the system's voltage.
• Breaking Capacity: Determine the necessary breaking capacity—the maximum fault current the MCCB can safely interrupt—to ensure adequate protection against potential high-fault conditions.

How to Order MCCBs from RS Australia

Looking for a trusted source for moulded case circuit breakers? RS Hong Kong offers a wide selection of high-performance MCCBs from leading brands such as Siemens, Schneider Electric, and ABB.

Whether you require thermal circuit breakers, distribution boards, circuit terminal blocks, or high-capacity MCCBs, RS Hong Kong makes the ordering process straightforward. You can easily purchase the moulded circuit breaker you need online through our website. Simply explore our extensive range of MCCBs and other circuit protection devices, complete your order, and have it delivered to your location. You can also pick up your order from a local branch.

Alternatively, our dedicated team is available to assist you with your moulded case breaker requirements. You can place your order or discuss your needs by calling us directly at 852 2421 9898.

How Delivery Works at RS Hong Kong

At RS Hong Kong, we understand the importance of receiving your moulded case circuit breakers promptly. We offer efficient delivery services for our extensive range of MCCBs, including various current ratings and types of moulded circuit breakers. For detailed information on our delivery options, timelines, and any applicable charges, please review our dedicated Delivery page.