MCB vs MCCB: Key Differences and How to Choose the Right Breaker

MCBs and MCCBs both protect circuits, but they are built for very different jobs. Choosing the wrong one can mean nuisance tripping or, worse, inadequate protection.

Key differences

• Rating – MCBs typically cover 1-63A; MCCBs handle 63A up to 1600A or more.
• Breaking capacity – MCBs are usually rated to 6-10kA, while MCCBs reach 36kA and beyond.
• Trip adjustment – MCCBs often feature adjustable thermal and magnetic settings.

Which one do you need?

Use an MCB for final distribution in homes and small panels. Use an MCCB as a main or branch protector in commercial and industrial boards where higher fault currents occur.