Which outcome occurs when a molded case circuit breaker (MCCB) fails to trip under sustained overload conditions?

💡 Explanation

When an MCCB fails to trip during overcurrent, excessive current flows through breaker components leading to increased resistive heating; if this exceeds thermal limits, thermal runaway occurs causing rapid temperature rise and potential fire. Therefore thermal runaway results, unlike flash which requires arcing, sag necessitates large but passing current, or resonance needs non-linear loads.

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