As a key protective component in medium and low-voltage power distribution systems, Mccb (Molded Case Circuit Breaker) plays an irreplaceable role in ensuring the safe and stable operation of electrical systems. Different from small-sized circuit breakers such as MCB, Mccb is designed for high-current, high-voltage scenarios, with stronger breaking capacity and more comprehensive protection functions. Zhejiang C&J Electrical co., ltd. (referred to as C&J Electrical) is dedicated to the R&D and production of high-performance electrical protection devices, and its CJMM1 series Mccb stands out with compact structure, excellent performance and flexible customization, providing reliable protection for various power distribution systems.
Core Overview of Mccb
Molded Case Circuit Breakers (MCCB) is a required component of electrical systems, providing overload protection and short-circuit protection. In most cases, MCCBs are installed in the main power distribution board of a facility, allowing the system to be easily shut down when necessary. Mccb is a closed-type circuit breaker with a plastic shell that encapsulates internal components such as contacts, tripping mechanisms and arc extinguishing systems, effectively isolating electrical hazards and ensuring safe operation.
Compared with traditional circuit breakers, Mccb has the advantages of large rated current, high breaking capacity, and multi-functional protection. It is widely used in the core link of power distribution systems, responsible for distributing electrical energy and protecting lines and equipment from fault damage. With the continuous upgrading of industrialization and intelligent power distribution requirements, high-performance Mccb has become a standard configuration in industrial plants, commercial buildings and large-scale electrical facilities.
Core Functions of Mccb
C&J Electrical’s CJMM1 series Mccb integrates multiple core protection functions, realizing all-round protection for power distribution systems and electrical equipment. Its main functions include:
- Overload protection: When the circuit current exceeds the rated value for a long time, the thermal tripping mechanism acts to cut off the circuit after a delay, preventing wire overheating, insulation aging and equipment damage caused by overload.
- Short-circuit protection: When a short-circuit fault occurs, the magnetic tripping mechanism responds instantly, cutting off the fault circuit in milliseconds to withstand the impact of short-circuit current and avoid the spread of hazards.
- Undervoltage protection: When the power supply voltage is lower than the rated value, the undervoltage release acts to cut off the circuit, preventing electrical equipment from being damaged due to low-voltage operation and ensuring the normal operation of the system.
- Power distribution function: It can reasonably distribute electrical energy in the power distribution system, realize on-off control of circuits, and facilitate daily maintenance and management of the system.
- Motor protection: It can be used as infrequent starting protection for motors, and provide overload, short-circuit and undervoltage protection for motors, ensuring the safe operation of motor equipment.
Application Scenarios of Mccb
With the characteristics of high breaking capacity, comprehensive protection and wide current adaptation range,Mccb is widely used in various medium and large-scale electrical scenarios. The main application fields are as follows:
- Industrial plants: Used in the main power distribution system and branch circuits of factories, protecting production equipment, motors, power lines and other components, adapting to the high-current and high-load working environment of industrial sites.
- Commercial and public buildings: Shopping malls, office buildings, hotels, hospitals and other large-scale buildings, installed in the main distribution board to protect the power supply of central air conditioning, elevators, lighting systems and other key equipment, ensuring the stable operation of the building’s electrical system.
- Power distribution stations: Used in low-voltage power distribution stations and substations, responsible for the final stage of power distribution and protection, ensuring the safe transmission of electrical energy to users.
- Infrastructure projects: Roads, bridges, tunnels and other infrastructure construction sites, used for temporary power distribution protection, adapting to the harsh and complex on-site working environment.
- Energy and chemical industry: Power distribution systems in oil refineries, chemical plants and other places, with high safety performance to cope with the special working environment with flammable and explosive risks.
- Data centers: Used in the power distribution system of data centers, protecting precision equipment such as servers and UPS power supplies, ensuring the continuous and stable operation of the data center.
C&J Electrical’s CJMM1 Series Mccb: Structural Features & Advantages
C&J Electrical’s CJMM1 series Mccb (Moulded Case Circuit Breaker) is a high-performance fixed-type product designed for medium and low-voltage power distribution systems. It integrates excellent protection performance and humanized structural design, fully meeting the needs of various industrial and commercial scenarios. The details are as follows:
Structural Features & Core Advantages
- Wide application range: Suitable for AC 50Hz/60Hz distribution network circuits, with rated insulation voltage 1000V, rated operating voltage up to 690V, and rated operating current from 10A to 1600A, adapting to various power distribution requirements.
- Excellent performance indicators: Small size, high breaking capacity, short arcing (or no arcing) characteristics, occupying less installation space while ensuring reliable fault breaking, and reducing arc hazards.
- Flexible installation methods: Supports vertical and horizontal installation, adapting to different installation environments and layout requirements of distribution boxes, improving installation convenience.
- Strong environmental adaptability: Adaptable to harsh working environments, with strict environmental temperature, altitude and humidity requirements, ensuring stable operation in various complex conditions.
- Customizable services: Supports OEM brand customization, and provides optional handle colors to meet the personalized needs of different customers and market segments.
- High safety performance: Integrates multiple protection functions, with reliable quality and stable performance, effectively protecting lines and equipment from fault damage.
Technical Parameters & Environmental Requirements
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Details
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Technical Parameters
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Frame current: 63A-1600A
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Rated current: 6A-1600A
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Rated operating voltage: 400/690V
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Rated insulation voltage: 1000V
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Environmental Temperature
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Installation altitude: Not exceeding 2000m
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Ambient air temperature: Upper limit ≤+40°C; 24-hour average ≤+35°C; Lower limit ≥-5°C
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Pollution level: 3
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Atmospheric Conditions
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Relative humidity ≤50% at +40°C; When the monthly average minimum temperature of the wettest month ≤+25°C, the average maximum relative humidity ≤90% (considering condensation due to temperature changes)
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Why Choose C&J Electrical’s CJMM1 Series Mccb?
In the field of Mccb, the CJMM1 series product from C&J Electrical has obvious competitive advantages, becoming the preferred choice for customers pursuing high quality and stable performance:
- Comprehensive protection: Integrates overload, short-circuit, undervoltage and other protection functions, and can be used for motor protection, meeting multi-scenario application needs.
- Excellent structural design: Small size, high breaking capacity, short arcing characteristics, and flexible installation methods, adapting to various installation environments and space constraints.
- Wide adaptability: Wide range of frame current and rated current, compatible with different power distribution systems, and strong environmental adaptability.
- Flexible customization: Supports OEM brand customization and handle color options, adapting to the personalized needs of different customers and markets.
- Reliable quality: Strict quality control and testing, in line with international electrical standards, ensuring long-term stable operation and safe use.
- Professional support: C&J Electrical has a professional technical team that can provide customers with tailored Mccb solutions and comprehensive after-sales services, solving customers’ worries.
Get in Touch
If you have any questions about the CJMM1 series Mccb, 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 high-quality electrical protection solutions and reliable services to ensure the safe and stable operation of your power distribution system.
Post time: Jan-26-2026