Molded Case Circuit Breakers

Molded Case Circuit Breakers (MCCBs) are essential core protection devices for modern low-voltage power distribution systems, widely adopted in industrial, commercial, and civil power scenarios. As a professional Adjustable MCCB and AC MCCB solution, the CJMM3 series MCCB launched by C&J Electrical (Zhejiang C&J Electrical co., ltd.) delivers stable and reliable circuit control and fault protection for low-voltage distribution lines. Different from miniature circuit breakers (MCBs) in application scenarios and performance parameters, MCCBs are designed for high-current, heavy-load power distribution environments with stronger breaking capacity and wider adaptability.

The CJMM3 series MCCB is a professional mechanical switch device that can connect, carry and break current under normal circuit conditions. Meanwhile, it can bear and cut off current within a specified period under abnormal circuit states, providing effective protection for power distribution lines and electrical equipment against overload, short circuit, and undervoltage faults (auxiliary function). This series covers frame grades of 125A, 160A, 250A, 400A and 630A, with a rated current range of 16A to 630A, realizing full coverage of conventional low-voltage heavy-load power distribution scenarios.

In terms of electrical performance, the product supports rated working voltages of 400/415V and 690V, matched with mainstream global low-voltage power supply standards. Its breaking capacity includes 20kA, 36kA, 50kA, 70kA and 75kA, covering all conventional short-circuit breaking requirements in the power distribution field. All products strictly comply with IEC60947-1 and IEC60947-2 international standards, with reliable quality and wide standard adaptability.

CJMM3 series AC MCCB adopts a standardized and modular structural design, with flexible configuration and strong scene adaptability. The product is a 3-pole device, equipped with two release types: single magnetic type and thermal magnetic type. Users can select the matching release mode according to actual load characteristics and protection requirements to achieve targeted circuit fault protection.

Regarding durability and protection level, the CJMM3 series features a front-side IP40 protection grade and Class III pollution degree adaptation, which can resist dust and minor external physical impact in conventional industrial and civil environments. The electrical life reaches 5000 times (low current specification) and 3000 times (high current specification), ensuring long-term stable operation of equipment and reducing frequent replacement costs. The product supports 50/60Hz dual-frequency operation, suitable for most regional power grid systems worldwide.

To ensure stable and consistent performance of the Adjustable MCCB, C&J Electrical has formulated strict applicable environmental standards for CJMM3 series products. The conventional working temperature ranges from -5°C to 40°C, adapting to most indoor power distribution scenarios. For special high and low temperature environments of -40°C ~ -5°C and 40°C ~ 70°C, the product can be used normally by referring to the temperature derating coefficient table to adjust parameters.

In terms of humidity adaptation, under the ambient temperature of +40°C, the product can adapt to a maximum relative humidity of 50%; under lower temperature conditions, the tolerable relative humidity is higher, up to 90% at +20°C, which can cope with humid environments such as coastal areas and workshops. The product storage temperature ranges from -40°C to 70°C. It is specified that if the storage temperature is lower than the normal working condition, the product needs to be placed in the working environment for at least 24 hours before use to ensure stable performance.

With complete specifications, high safety performance and strong environmental adaptability, CJMM3 series molded case circuit breakers are widely used in low-voltage power consumption fields such as electric power engineering, building construction, industrial production and OEM supporting. In power distribution stations and power transmission projects, it serves as the main circuit protection device to ensure the safe operation of power transmission lines; in commercial buildings, residential communities and public facilities, it provides overload and short-circuit protection for central air conditioning, power distribution cabinets and other equipment.

In industrial scenarios such as manufacturing workshops, mechanical equipment and automated production lines, the high breaking capacity and stable fault response performance of CJMM3 MCCBs can effectively avoid equipment damage and production shutdown caused by sudden short-circuit and overload faults. In addition, it is highly suitable for OEM supporting scenarios, providing standardized and customized power protection accessories for electrical equipment manufacturers.

As a professional MCCB manufacturer, C&J Electrical focuses on diversified product services and flexible supply modes. The CJMM3 series supports OEM/ODM brand customization services, which can carry out personalized customization including product logo, parameter fine-tuning, packaging and scheme matching according to customer project requirements. The product has a complete specification system with multiple current levels, breaking capacities and installation modes for customers to choose, realizing one-stop matching of different project demands.

CJMM3 series molded case circuit breakers integrate stable performance, diverse specifications, flexible installation and strong environmental adaptability, being reliable AC MCCB and Adjustable MCCB products in the low-voltage power distribution industry. Whether for conventional civil power distribution, industrial heavy-load operation or customized OEM supporting projects, this series of products can provide targeted protection solutions. C&J Electrical adheres to strict production standards to guarantee product quality stability. If you have product consultation, parameter selection, customization demands or any questions, please feel free to contact us at any time.