An arcing current in the short-time delay region of a trip curve takes how long to clear compared to the instantaneous region?

In the context of circuit protection, the characteristics of trip curves are crucial to understanding how different types of protection devices respond to overcurrent conditions. The short-time delay region is designed for temporary faults where a certain amount of overcurrent can be tolerated for a limited time without tripping the circuit breaker. This allows for brief surges during normal operation (such as motor start-up currents) while still providing protection against longer-lasting, more damaging faults.

When considering the instantaneous region, the circuit protection device will trip very quickly, often within milliseconds, when a fault condition arises. It is intended to protect against severe overloads or short-circuits immediately.

In contrast, the arcing current within the short-time delay region will typically take longer to clear. This is because it allows a certain amount of current to flow for a specified period (measured in seconds) before the breaker trips. As a result, arcing currents can persist longer because of this intentional delay in tripping, allowing for the operational flexibility needed in systems while still ultimately ensuring protection from prolonged overcurrents.

Thus, it's clear that arcing currents in the short-time delay region will take longer to clear when compared to the almost instantaneous response of the protection device in the instantaneous trip region