A recloser will provide protection for any circuit that has the capacity downstream to generate the needed fault current to trip it.

A recloser will provide protection for any circuit that has the capacity downstream to generate the needed fault current to trip it.

• A. True
• B. False
• C. Not always
• D. Only if a fault is detected

Answer: (A)

The main idea is that a recloser trips based on the amount of fault current flowing downstream. It has a pickup setting, and when the current shown on the line exceeds that setting, the recloser opens to interrupt the fault. If the downstream system can supply enough fault current to push the current above the recloser’s pickup, the device will trip and protect the circuit. After tripping, it will attempt to recluse to determine if the fault is temporary; if the fault is cleared, service is restored, and if not, the protective sequence continues. So, when there is sufficient fault current available downstream to reach the recloser’s trip threshold, protection is provided by the recloser. If the fault current is too small (high-impedance faults, distant faults with limiting impedance, etc.), the recloser may not trip, which is also why special fault scenarios exist, but the statement describes the standard, intended behavior.

The main idea is that a recloser trips based on the amount of fault current flowing downstream. It has a pickup setting, and when the current shown on the line exceeds that setting, the recloser opens to interrupt the fault. If the downstream system can supply enough fault current to push the current above the recloser’s pickup, the device will trip and protect the circuit. After tripping, it will attempt to recluse to determine if the fault is temporary; if the fault is cleared, service is restored, and if not, the protective sequence continues.

So, when there is sufficient fault current available downstream to reach the recloser’s trip threshold, protection is provided by the recloser. If the fault current is too small (high-impedance faults, distant faults with limiting impedance, etc.), the recloser may not trip, which is also why special fault scenarios exist, but the statement describes the standard, intended behavior.