In low-voltage electrical systems, short circuits are one of the most dangerous faults, which may cause equipment burnout, electrical fires and other serious hazards. For this question, the answer is definite: MCB(Miniature Circuit Breaker) can effectively protect against short circuits. As a core protective component in modern low-voltage electrical systems, MCB not only undertakes overload protection tasks but also plays a key role in short circuit protection. Zhejiang C&J Electrical co., ltd. (referred to as C&J Electrical) has rich experience in the research and production of MCB(Miniature Circuit Breaker). Its launched CJM5-63 series miniature circuit breaker has excellent short circuit protection performance, providing reliable safety guarantee for homes, offices and industrial scenarios.
MCB’s Short Circuit Protection Principle & Core Role
MCBs also provide protection against short circuits, which occur when an electrical current travels through an unintended path. Short circuits can cause significant damage to the electrical system and can even cause fires. MCBs quickly trip in the event of a short circuit, preventing damage and potential hazards. The short circuit protection function of MCB(Miniature Circuit Breaker) is realized by the built-in magnetic tripping mechanism. When a short circuit occurs, the current in the circuit will rise sharply instantaneously (usually reaching dozens of times the rated current). At this time, the strong current will generate a strong magnetic field in the magnetic tripping mechanism of the MCB, which drives the tripping component to act in milliseconds, quickly cutting off the circuit and isolating the faulty part from the power supply.
Compared with traditional fuses, the short circuit protection of MCB(Miniature Circuit Breaker) has obvious advantages: it can trip more quickly and accurately, avoid the expansion of fault hazards; after tripping, it can be reset manually and reused without replacing components, which is more convenient and economical; at the same time, it can also realize overload protection while completing short circuit protection, achieving dual protection for the circuit.
Overview of MCB(Miniature Circuit Breaker)
MCB(Miniature Circuit Breaker) is an automatically operated low-voltage electrical switch, which is widely used in low-voltage power distribution systems such as homes, offices and industrial sites. Its core function is to protect electrical installations against overloads and short circuits, ensuring electrical safety. The shell of MCB is usually made of high-quality insulating materials, which can effectively isolate internal components and prevent electric arc leakage during operation.
Different from other circuit breakers, MCB(Miniature Circuit Breaker) has the characteristics of small volume, light weight, convenient installation, reliable performance and low cost. It is usually installed on a 35mm DIN rail, which is easy to integrate into various distribution boxes. At the same time, MCB is equipped with two tripping mechanisms: the delayed thermal tripping mechanism for overload protection and the magnetic tripping mechanism for short circuit protection. These two mechanisms work independently and cooperate with each other to form a comprehensive protection system for the circuit.
Core Functions of MCB(Miniature Circuit Breaker)
In addition to the core short circuit protection function, MCB(Miniature Circuit Breaker) also integrates multiple practical functions, which are crucial to the safe and stable operation of the electrical system:
- Overload protection: Through the delayed thermal tripping mechanism, when the circuit current exceeds the rated value for a long time (such as connecting too many high-power electrical appliances at the same time), the bimetallic strip in the thermal tripping mechanism is heated and deformed, driving the MCB to trip after a certain delay, preventing the wire from overheating and aging or even catching fire.
- Circuit on-off control: It can manually control the on-off of the circuit, which is convenient for daily maintenance, inspection and power-off operation of the electrical system.
- Contact position indication: Most MCBs are equipped with clear contact position indicators, which can intuitively display whether the circuit is on or off, facilitating users to check the circuit status and troubleshoot faults.
- Isolation function: After tripping, the MCB can reliably isolate the faulty circuit from the power supply, ensuring the safety of maintenance personnel during inspection and maintenance operations.
C&J Electrical’s CJM5-63 Series MCB: Core Advantages & Product Overview
C&J Electrical’s CJM5-63 series MCB(Miniature Circuit Breaker) is a high-performance product designed for homes, offices and industrial applications. It protects electrical installations against overloads and short circuits to ensure electrical safety. Once a fault is detected, the miniature circuit breaker automatically switches off the electrical circuit to prevent damage to wires and to avoid the risk of fire. Equipped with dual tripping mechanisms, it warrants reliability and safety for people and assets. Its core advantages, structural features and technical parameters are as follows:
Core Structural Features & Advantages
- High short-circuit capacity: 4.5KA/6KA short-circuit breaking capacity optional, which can reliably handle short-circuit faults and ensure the safety of the electrical system.
- Wide current protection range: Designed to protect circuits carrying large current up to 63A, covering the current demand of most low-voltage electrical scenarios.
- Clear contact position indication: Facilitates users to check the circuit status and quickly locate faults, improving the convenience of use and maintenance.
- Versatile application: Can be used as the main switch in household and similar installations, with strong adaptability to different application scenarios.
- Customizable options: Handle color customizable; supports OEM/ODM brand customization services, meeting the personalized needs of different customers and market segments.
- Reliable quality: Complies with IEC60898/EN60898 international standards, with stable performance and long service life.
Key Technical Parameters
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Parameter
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Details
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|---|---|
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Rated Current
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6A, 10A, 16A, 20A, 25A, 32A, 40A, 50A, 63A
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Rated Voltage
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230/400VAC (240/415VAC)
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Rated Frequency
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50/60Hz
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Number of Pole
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1P, 2P, 3P, 4P (1P+N, 3P+N)
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Module size
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18mm
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Curve type
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B, C, D Type
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Breakering capacity
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6000A
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Optimum operating temperature
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-5℃ to 40℃
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Terminal Tightening torque
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5N-m
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Terminal Capacity (top)
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25mm²
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Terminal Capacity (bottom)
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25mm²
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Electro-mechanical endurance
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4000cycles
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Mounting
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35mm DinRail
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Suitable Busbar
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PIN Busbar
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Wide Application Scenarios of CJM5-63 Series MCB
With reliable protection performance and strong adaptability, the CJM5-63 series MCB(Miniature Circuit Breaker) is widely used in various low-voltage electrical scenarios, including:
- Household scenarios: Residences, villas, apartments – used for protection of branch circuits such as living rooms, bedrooms, kitchens, and bathrooms (e.g., air conditioners, water heaters, refrigerators, washing machines and other electrical appliances).
- Commercial office buildings: Offices, shopping malls, hotels, restaurants – protection of lighting circuits, socket circuits, office equipment circuits and small power equipment circuits.
- Small industrial sites: Small factories, workshops, workshops – protection of low-power production equipment circuits, auxiliary electrical circuits and lighting circuits.
- Public facilities: Schools, kindergartens, community activity centers – protection of public electrical circuits that require high safety and reliability.
- Electrical equipment matching: Matching with distribution boxes, control cabinets, power distribution panels and other electrical equipment, used as internal protective switches to improve the safety performance of the whole equipment.
Why Choose C&J Electrical’s CJM5-63 Series MCB(Miniature Circuit Breaker)?
In the field of MCB(Miniature Circuit Breaker), the CJM5-63 series product from C&J Electrical has obvious competitive advantages:
- Excellent short circuit protection: High short-circuit breaking capacity, fast and reliable tripping, effectively preventing short-circuit hazards and ensuring the safety of people and property.
- Dual reliable protection: Equipped with thermal and magnetic dual tripping mechanisms, which can accurately respond to overload and short circuit faults, realizing comprehensive protection of the circuit.
- Wide adaptability: Multiple pole numbers, current levels and curve types optional, adapting to different electrical scenarios and load characteristics.
- Humanized design: Small module size, convenient installation; clear contact position indication, easy to use and maintain; customizable handle color, meeting personalized needs.
- Reliable quality and perfect service: Complies with international standards, with strict quality control; provides OEM/ODM customization services and professional after-sales technical support, solving worries for customers.
Get in Touch
If you have any questions about the CJM5-63 series MCB(Miniature Circuit Breaker), such as product specifications, technical details, customization needs, or bulk orders, please feel free to contact C&J Electrical. Our professional team will provide you with tailored low-voltage electrical protection solutions to ensure the safe and stable operation of your electrical system.
Post time: Jan-06-2026