16 views, last update: 15 January 2024, reading time: 10 minutes
In this article, from the series of articles of GeeTech Group, we get to know about the molded case circuit breaker and talk about its uses, structure and difference from circuit breakers and brands in the market.
Table of contents of this article
- what is a molded case circuit breaker
- molded case circuit breaker applications
- molded case circuit breaker types
- molded case circuit breaker vs circuit breaker
- molded case circuit breaker diagram
- Schneider molded case circuit breaker
- Siemens molded case circuit breaker
- ABB molded case circuit breaker
- molded case circuit breaker price
what is a molded case circuit breaker
Molded Case Circuit Breakers (MCCBs) are essential electrical protection devices that safeguard your appliances and circuits from excessive current. With adjustable trip settings, MCCBs can handle current ratings up to 2,500 amps. They are compatible with voltages across a wide range and operate at frequencies of 50 and 60 Hz. MCCBs perform three key functions:
Fault Protection: Instantly interrupts high-current flow caused by line faults or short circuits, providing rapid protection against electrical faults.
Overload Protection: Guards against prolonged periods of current surpassing the rated value, offering defense against overload situations.
On/Off Capability: Enables easy circuit switching for repair and replacement purposes.
molded case circuit breaker applications
Molded Case Circuit Breakers (MCCBs) find a range of applications due to their ability to handle high currents. Here are some common uses of MCCBs:
1. Generator Protection: MCCBs are essential in protecting generators, which often produce high currents and require reliable protection against overcurrent conditions.
2. Electric Feeder Protection: MCCBs are suitable for distributing electric current through feeder circuits, which can carry significant amperage. MCCBs can be customized with trip settings to accommodate additional circuits.
3. Welding Machines: MCCBs are ideal for welding applications that draw substantial currents. Unlike miniature circuit breakers, which have limitations, MCCBs can handle the high currents associated with welding operations.
4. Capacitor Bank Protection: In industrial and commercial electrical systems, capacitor banks are used to correct power factors. MCCBs provide necessary protection against high currents drawn by capacitor banks, helping to reduce potential damage.
5. Motor Protection: Electric motors require effective protection, and MCCBs excel in providing this safeguard. MCCBs can adjust for inrush currents and offer overload protection without unnecessary tripping.
6. Adjustable Trip Settings for Low-Current Applications: Despite being commonly used in high-current applications, MCCBs can also be employed in scenarios with lower currents. Their adjustable trip settings make them versatile for a wide range of current requirements.
In summary, MCCBs offer reliable protection for various heavy-duty applications, including generator systems, electric feeders, welding machines, capacitor banks, motors, and even low-current applications.
molded case circuit breaker types
There are various types of molded case circuit breakers (MCCBs) available, each designed for specific applications and requirements. Here are some common types:
1. Thermal Magnetic MCCBs: These MCCBs combine thermal and magnetic trip mechanisms. They provide protection against overloads (thermal protection) and short circuits (magnetic protection). Thermal magnetic MCCBs are widely used for general-purpose applications.
2. Electronic MCCBs: These MCCBs use electronic trip units instead of thermal or magnetic mechanisms. Electronic MCCBs offer more precise and adjustable trip settings, advanced monitoring features, and enhanced protection against arc faults. They are often used in sensitive and critical applications.
3. Compact MCCBs: Compact MCCBs are designed to save space and provide high-performance protection. They have compact sizes, making them suitable for applications with limited panel space or where multiple MCCBs need to be installed.
4. Ground Fault MCCBs: Also known as Ground Fault Circuit Interrupters (GFCIs) or Residual Current Circuit Breakers (RCCBs), these MCCBs provide protection against ground faults and electrical shocks. They quickly trip when sensing a leakage of current to the ground, preventing potential harm to personnel or equipment.
5. High-Interrupting Capacity MCCBs: These MCCBs are built to handle exceptionally high fault currents. They are used in applications where there is a risk of large short-circuit currents, such as in industrial power systems or distribution networks.
6. Adjustable Trip MCCBs: These MCCBs allow users to adjust the trip current settings within a specified range. They offer flexibility to accommodate varying current requirements and can be fine-tuned for specific applications.
7. Motor Protection MCCBs: Motor protection MCCBs are specifically designed to protect electric motors from overloads, short circuits, and other motor-related faults. They often incorporate features like adjustable overload and inrush current settings.
molded case circuit breaker vs circuit breaker
When it comes to protecting electrical circuits and sensitive electronic equipment from voltage spikes or currents, molded case circuit breakers (MCCBs) are an ideal choice. They provide reliable overload and short-circuit protection, making them suitable for use in large electrical systems found in industrial facilities, warehouses, and commercial buildings.
While standard breakers are commonly used for residential and light commercial applications, MCCBs are designed to handle the higher demands of industrial and heavy commercial settings. One key difference between the two is the higher interrupting capacity of an MCCB, allowing it to handle larger loads.
MCCBs often come with additional features such as adjustable trip settings or a thermal-magnetic trip element, which might not be available in standard breakers. It’s important to select the right device based on your specific needs and ensure it meets or exceeds the National Electrical Code requirements for your application.
To safely install the breaker, gather the necessary tools such as screwdrivers, wire cutters/strippers, pliers, a voltage tester, and gloves. Before installation, ensure that all components are properly rated for their intended use.
When installing the breaker into an existing panel, double-check all connections to ensure they are secure and properly insulated before turning on the power source. This precaution minimizes the risk of hazards caused by loose connections, damaged insulation, or bare metal contacts within the breaker box.
For a successful installation and optimal protection, it’s important to follow safety guidelines and choose the appropriate MCCB for your electrical system.
molded case circuit breaker diagram
An MCCB is made from the following main parts each one explained in detail
Arc chute
Contacts
Operating mechanism
Terminal Connector
Thermal Trip Unit
Magnetic Trip Unit
Handle / Trip-free Mechanism
Trip Button
Arc chute:
In a typical MCCB, one of the important components is the arc chute. The arc chute is comprised of parallel metal plates that are insulated from each other. Its primary function is to extinguish the electric arc by dividing and lengthening it. Sometimes referred to as an arc divider or arc splitter, these plates are typically constructed using ferromagnetic material.
By utilizing an arc chute in an MCCB, the electrical arc is effectively managed and extinguished, ensuring the safety and proper functioning of the circuit. The design of the arc chute enables it to effectively handle and control the arc generated during the operation of the circuit breaker.
Contacts:
In a typical MCCB, contacts play a critical role as metallic conductors that facilitate the flow of current to the load. There are two types of contacts: fixed and moving contacts. These contacts are crafted from arc-resistant material with low resistivity and corrosion properties. The quality of the material used greatly influences the lifespan and performance of the circuit breaker.
Operating Mechanism:
The operating mechanism in an MCCB is responsible for the controlled opening and closing of the current-carrying contacts. This mechanism is closely connected to the trip unit, which triggers its operation. The trip unit operates through a combination of thermal and magnetic mechanisms. These mechanisms provide a reliable and efficient response to ensure the safe and effective operation of the MCCB.
Terminal Connector:
Terminal connectors are essential components used to establish connections between the MCCB and the external circuit. The upper terminals are specifically designated for output/load connections, while the lower terminals are meant for input/supply connections. It’s important to note that although these connectors are bidirectional, the input/output designation primarily stems from their physical installation.
Trip Unit:
The trip unit plays a critical role in activating the operating mechanism of an MCCB. This unit incorporates various mechanisms, including thermal and magnetic tripping functions, along with a dedicated test button for testing purposes.
Thermal Trip Unit:
The thermal trip unit relies on a bimetallic strip mechanism to detect and respond to overloading conditions. When the temperature rises beyond a certain threshold due to excessive current, the bimetallic strip bends, thereby triggering the opening of contacts as a protective measure.
Schneider molded case circuit breaker
Schneider Electric is a reputable manufacturer known for its high-quality molded case circuit breakers (MCCBs). MCCBs are essential components in electrical distribution systems as they protect against overcurrents and short circuits. Schneider’s MCCBs are designed to provide reliable and efficient protection for various applications, from residential to industrial settings.
Schneider’s MCCBs feature advanced technology and robust construction, ensuring optimal performance and durability. They are available in different current ratings, breaking capacities, and trip unit options to suit specific electrical requirements. The trip units can include thermal magnetic, electronic, or microprocessor-based trip units, providing accurate and customizable protection settings.
These MCCBs are equipped with various features like adjustable thermal and magnetic trip settings, indicating LEDs for status monitoring, and auxiliary contacts for remote signaling and control. Additionally, Schneider offers a range of accessories and modular add-ons to enhance the functionality and adaptability of their MCCBs.
Overall, Schneider’s molded case circuit breakers are trusted solutions that prioritize safety and reliability in electrical systems, making them a popular choice among professionals in the industry.
You can contact GeeTech Group for free consultation and purchase of Schneider brand molded case circuit breaker products.
Siemens molded case circuit breaker
Siemens is a well-known manufacturer of high-quality molded case circuit breakers (MCCBs). MCCBs are essential components in electrical distribution systems as they protect against overcurrents and short circuits. Siemens offers a wide range of MCCBs suitable for residential, commercial, and industrial applications.
Siemens’ MCCBs are designed with advanced features and technologies to ensure reliable and efficient protection. They are available in different current ratings, breaking capacities, and trip unit options to meet specific electrical requirements. The trip units can include thermal magnetic, electronic, or microprocessor-based trip units, providing accurate and versatile protection settings.
These MCCBs from Siemens are known for their robust construction, allowing them to withstand high currents and harsh environmental conditions. They are equipped with features such as adjustable trip settings, indicating LEDs for status monitoring, and auxiliary contacts for remote signaling and control. Siemens also offers additional accessories and modular add-ons to expand the functionality and adaptability of their MCCBs.
Siemens’ molded case circuit breakers are trusted by professionals in the industry due to their high performance and reliability. They contribute to the safety and protection of electrical systems in various settings.
You can contact GeeTech Group for free consultation and purchase of Siemens brand molded case circuit breaker products.
ABB molded case circuit breaker
ABB is a renowned manufacturer of molded case circuit breakers (MCCBs) that provide reliable and efficient protection in electrical distribution systems. MCCBs are essential components for safeguarding against overcurrents and short circuits.
ABB offers a wide range of MCCBs suitable for diverse applications, including residential, commercial, and industrial settings. These MCCBs are designed with advanced technologies and features to ensure optimal performance. ABB’s MCCBs are available in various current ratings, breaking capacities, and trip unit options to meet specific electrical requirements.
The trip units of ABB MCCBs can be thermal magnetic, electronic, or equipped with integrated microprocessors. This allows for precise and customizable trip settings, enhancing the accuracy of protection. The MCCBs also come with adjustable or fixed trip settings and a wide range of current ratings to suit different load requirements.
ABB’s MCCBs feature robust construction, enabling them to withstand high currents and operate reliably in harsh environmental conditions. Additional features may include indicating LEDs for status monitoring, auxiliary contacts for remote signaling and control, and compatibility with various accessories for extended functionality and adaptability.
ABB’s reputation in the industry stems from their commitment to quality and innovation. Their molded case circuit breakers ensure the safety and protection of electrical systems in diverse applications.
You can contact GeeTech Group for free consultation and purchase of ABB brand molded case circuit breaker products.
molded case circuit breaker price
To get the original molded case circuit breaker price list with different brands, you can contact our experts at GeeTech Group. You can also call +90 (342) 502 22 62 or send a message via WhatsApp for free advice and product purchase guidance.