Overtime; NCAA No Game clock
Say a time out is called. 25 second play clock when the ready is signaled.
Injury timeout 25 second clock when the ready is signaled
First downs 40 second play clock when the ball and chains are set
two different play clock scenarios
When the 40-second play clock is being used, it starts when the ball becomes dead on the previous down (with the philosophical pause+breath, then start). It has nothing to do with spotting the ball or setting the chains.
In regulation or Extra Periods, for the first down of a possession series, or any ‘administrative’ stoppage (penalty completion, time out (R or charged Team), measurement), offensive team helmet off, offensive team injury, the play clock is 25 and starts on the Referee’s signal. Similar with defensive helmet off and defensive injury, but a 40-second play clock. But, by rule, unrelated to ball spotting or chain status (but we’d always wait until both are ready to signal the RFP).
So, for the PCO, his part in Extra Periods is identical to regulation play, with the exception that EVERY down would have a play clock. There would never be a down in which the play clock would be ‘held’ (like it would when the time remaining on the game clock is less the play clock duration). The game clock might need to remain ON and displaying 0:00 for the play clocks to work - I couldn’t say. But, the GCO can pack up and go home.
Spotting the ball and the chains have nothing to do with operation of the play clock.