Single Shot Reset Time
The Single Shot Reset timer starts when the switchgear is manually closed and runs for the pre-set number of seconds. The default setting is 1 s and it can be configured for between 0 s and 180 s.
If the Single Shot Reset Timer is configured for zero seconds, Single Shot mode will not be activated by a manual close and Auto Reclose will always be enabled if it’s On.
The Single Shot Reset Time setting can be found in WSOS on the
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The Single Shot Reset Timer can also be configured on the operator interface.
There are a number of scenarios that can occur involving the Single Shot Reset Timer.
Scenario 1 – Single Shot Timer initiated by an operator close.
This is the normal operation.
The single shot timer starts to run when an operator close occurs.
If no fault is detected, the timer times out, the switchgear goes into Auto Reclose mode if configured and stays closed.
Scenario 2 – Protection Pickup during Single Shot timing.
In this scenario a protection pickup occurs during the Single Shot running time which resets the Single Shot Timer.
If the fault persists, a single shot trip will occur after the time to trip expires.
Scenario 3 – Protection Reset during Single Shot timing.
If a pickup that occurred while the single shot timer was running is followed by a protection reset, the single shot timer will restart.
The ACR will continue to be in single shot mode until the timer expires.