5-194 N60 NETWORK STABILITY AND SYNCHROPHASOR MEASUREMENT SYSTEM – INSTRUCTION MANUALCONTROL ELEMENTS CHAPTER 5: SETTINGS5When set to “Synchronize,” the selector switch acts as follows. For two power cycles, the selector applies position 0 to theswitch and activates SELECTOR 1 PWR ALARM. After two power cycles expire, the selector synchronizes to the positiondictated by the three-bit control input. This operation does not wait for time-out or the acknowledging input. When thesynchronization attempt is unsuccessful (that is, the three-bit input is not available (0,0,0) or out of range), then the selectorswitch output is set to position 0 (no output operand selected) and an alarm is established (SELECTOR 1 PWR ALARM).The operation of “Synch/Restore” mode is similar to the “Synchronize” mode. The only difference is that after anunsuccessful synchronization attempt, the switch attempts to restore the position stored in the relay memory. The “Synch/Restore” mode is useful for applications where the selector switch is employed to change the setting group in redundant(two relay) protection schemes.SELECTOR 1 EVENTS — If enabled, the following events are logged:The following figures illustrate the operation of the selector switch. In these diagrams, “T” represents a time-out setting.Event name DescriptionSELECTOR 1 POS Z Selector 1 changed its position to ZSELECTOR 1 STP ALARM The selector position pre-selected via the stepping up control input has not been confirmed before thetime outSELECTOR 1 BIT ALARM The selector position pre-selected via the three-bit control input has not been confirmed before the timeout
