If the time between 2 arcs is too long, the second one resets the counter.
This time is called TCQ : Time for counting qualification.Typically TCQ is 1.3 second , that means 0,8 s after the restart for a typical Tstop of 0.5 second.
If an arc occurs within 1.3 s after a previous one, it is counted.
The counter is reset if a new arc occurs 1.3 second or more after the previous one.
TCQ can be factory set between 1 and 6 seconds.