C
In MARK VIe, there is a protective trip called stale speed.
It is stated in manual that it will monitor the main speed pickups instead of overspeed pickups connected to it's terminal board TRPO.
It also states that if the speed pick up value was not changing for consecutive 100 frame periods, the corresponding IO pack of PPRO will deenergize it's own emergency trip relay?
what is the criticality of this trip? and why PPRO will monitor the speed of main speed pick ups (77NH-1, 2, 3) instead of its own over speed pick ups (77NH-4,5,6)?
Can anybody explain?
It is stated in manual that it will monitor the main speed pickups instead of overspeed pickups connected to it's terminal board TRPO.
It also states that if the speed pick up value was not changing for consecutive 100 frame periods, the corresponding IO pack of PPRO will deenergize it's own emergency trip relay?
what is the criticality of this trip? and why PPRO will monitor the speed of main speed pick ups (77NH-1, 2, 3) instead of its own over speed pick ups (77NH-4,5,6)?
Can anybody explain?