Conditional Auto Reclose Operation

• Separate IOEX outputs are asserted for each downstream DG device when the controller sends a trip signal to the ACR switchgear.

• These outputs are used to send trip signals (commonly known as Transfer Trip Signals) to the DG devices.

• When each DG device trips, it sends a signal back to the ACR to assert an IOEX input that identifies with that particular device.

• When a trip confirmation signal has been received from each DG device, the logic for the IOEX Conditional Auto Reclose input becomes true and the Auto Reclose inhibit is removed.

There are a number of scenarios that can occur.

Scenario No 1 – All trip confirmation signals received from DG devices within the Reclose Time.

• If the applicable Auto Reclose Time has not already expired before all of the DG confirmation signals are received, the ACR will automatically reclose as configured.

Scenario No 2 – All DG trip confirmation signals received within the Auto Reclose Conditional Timeout period.

• If the Auto Reclose Time expires before the trip confirmation signal is received from all of the DG devices, automatic reclose will still occur providing they are all received within the Auto Reclose Conditional Timeout period.

Scenario No 3 – Some DG trip confirmation signals received after the Auto Reclose Conditional Timeout period.

• If not all of the DG trip confirmation signals have been received by the time the Auto Reclose Conditional Timeout period expires, the ACR will go to Lockout.