EATON HJW Series Complete Molded Case Circuit Breakers, J Frame

What is the difference between MCCBs and MCBs?

• MCCBs safeguard equipment from fault currents & excess temperature rise, while MCBs protect items against current overloads.
• MCBs retain comparatively low interrupting ratings as compared to MCCBs.
• The tripping circuit of MCBs are fixed, while MCCBs have a movable tripping circuit.

Does temperature affect moulded case circuit breakers?

Extreme heat can cause circuit breakers to trip, even without an overload, as the bimetallic strip inside flexes and contacts to activate the breaker.

How are circuit breakers better than fuses?

• Circuit breakers can be easily reset and reused after tripping, while fuses cannot be reused if blown once.
• Circuit breakers offer precise protection by tripping at specific current thresholds, whereas fuses may have varying trip characteristics, making it difficult to find the exact fuse rating for a circuit.
• Circuit breakers often include ground fault protection (GFCI) and arc fault detection (AFCI), enhancing safety against electrical shocks and fire hazards. Fuses lack these built-in sensing capabilities.