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Weekly Product Spotlight: Demystifying the SJKM1 Series Molded Case Circuit Breaker (MCCB)
What is an MCCB?
An MCCB is a vital component in electrical distribution systems, designed to protect circuits from damage caused by overcurrent, short circuits, and, in some models, undervoltage. Its key feature is a molded insulating housing that encapsulates all critical components—contacts, arc chute, mechanism, and trip unit—into a compact, safe, and robust unit. This makes it a superior and safer alternative to traditional fuses and knife switches.
Core Working Principle
The SJKM1 series utilizes two primary protection mechanisms. For Overload Protection, a thermal element (bimetal strip) heats up and bends gradually during a sustained overcurrent, eventually triggering the mechanism to trip. For Short-Circuit Protection, a magnetic element (solenoid) reacts instantaneously to a sudden, massive current surge, providing rapid disconnection to prevent catastrophic damage. Advanced electronic trip units offer even more precise and configurable protection settings.
SJKM1 Series Specifications & Applications
The SJKM1 series offers a comprehensive range from 63A to 1250A, with both 3-Pole and 4-Pole configurations. It features a robust Rated Insulation Voltage of 690V/1000V and is suitable for systems with a Rated Operational Voltage of AC 400V/690V. With different Breaking Capacity levels (L/M/H), it can be selected to match the specific fault current requirements of the installation.
These MCCBs are engineered for diverse applications, serving as main switches, branch circuit protectors, and motor protection devices. They are commonly found in power distribution boxes, control panels for industrial machinery, the low-voltage side of distribution transformers, and commercial building power systems.
About Us:
Mingri Electric Co., Ltd. is a leading provider of high-quality electrical components and solutions, specializing in switchgear,circuit breakers,switches, etc. We are dedicated to delivering innovative products that meet the evolving needs of the global power industry.