What is a Hager MCCB? A Hager MCCB is a Moulded Case Circuit Breaker used to protect electrical circuits from overloads and short circuits while also providing switching and isolation functions. Where is Hager MCCB used? Hager MCCBs are used in industrial plants, commercial buildings, distribution boards, control panels, electrical switchboards, and other low-voltage electrical distribution systems. What is the difference between MCB and MCCB? MCBs are generally used for lower-current circuit protection, while MCCBs are designed for higher current ratings and typically offer greater protection and configuration options.