When an electrical system experiences abnormal currents (such as short circuits or severe overloads), if the circuit breaker fails to trip correctly within an extremely short time, it can lead to serious consequences including cable overheating, equipment damage, fires, explosions, and even endanger human lives.

Common causes of circuit breaker failure include:

• Circuit breaker malfunction (e.g., aging, mechanical jamming, internal burnout)

• Secondary control circuit failure (e.g., relay or signal line malfunction)

• Incorrect protection settings (e.g., improper current thresholds or time delay configurations)

• Faulty detection systems (failure to correctly detect abnormal currents)

• External control errors (miscommands from intelligent control systems)
   

Response Time Requirements for Abnormal Currents:

• AC (Alternating Current) Systems: Abnormal currents must be isolated within the **1Hz safe transient time (~16.6 milliseconds)**.

• DC (Direct Current) Systems: Must be fused or disconnected within less than 8 milliseconds.

Failure to promptly cut off will cause rapid overheating of cables and equipment, potentially leading to explosions, major fires, and power outage incidents.
 

Real-World Case Studies:

• Taiwan High-Speed Rail contact network incident: Protective devices failed to trip properly, causing power delays and affecting tens of thousands of passengers.

• California blackout (USA): Minor faults escalated into a regional blackout due to circuit breaker failure to act in time.

• Factory fire: Investigation revealed a short circuit followed by protective device failure, eventually igniting large quantities of flammable materials.

• Motor fire in Taiwan industrial park: Incorrect settings prevented timely power cutoff, resulting in motor burnout and production line shutdown.

• South Africa Eskom substation fire: Aged circuit breakers failed to trip after a transformer short circuit, causing a massive power outage affecting millions and severe economic losses.
   

POCT's Solution:

POCT technology can:

• Handle secondary control circuit failures

• Handle incorrect protection settings

• Handle faulty detection systems

• Handle external control anomalies
  Even under such conditions, POCT can still immediately and correctly isolate abnormal currents, ensuring fault fusing or source disconnection within 0.001 seconds, effectively preventing fires and explosions.

POCT – Making Safety Not Just an Ideal, But a Reality!