DARREC Shot pointer controller - Arc protection - Motor protection - Feeder protection - Back-up protection - Technical Manual - REX610 Protection and control - Relion Protection and Control - 1.2 - IEC - ANSI - 19.04.2024

REX610 Technical Manual

The execution of a reclose sequence is controlled by a shot pointer. It can be adjusted with the SHOT_PTR monitored data.

The shot pointer starts from an initial value "1" and determines according to the settings whether or not a certain shot is allowed to be initiated. After every shot, the shot pointer value increases. This is carried out until a successful reclosing or lockout takes place after a complete shot sequence containing a total of five shots.

Figure 1. Shot pointer function

Every time the shot pointer increases, the reclaim time starts. When the reclaim time ends, the shot pointer sets to its initial value, unless no new shot is initiated. The shot pointer increases when the reclose time elapses or at the falling edge of the INC_SHOTP signal.

When SHOT_PTR has the value six, the AR function is in a so called pre-lockout state. If a new initiation occurs during the pre-lockout state, the AR function goes to lockout. Therefore, a new sequence initiation during the pre-lockout state is not possible.

The AR function goes to the pre-lockout state in the following cases:
  • During SOTF
  • When the AR function is active, it stays in a pre-lockout state for the time defined by the reclaim time
  • When all five shots have been executed
  • When the frequent operation counter limit is reached. A new sequence initiation forces the AR function to lockout.