CHAPTER 4: SETPOINTS MONITORING889 GENERATOR PROTECTION SYSTEM – INSTRUCTION MANUAL 4–293Breaker Health The 889 relay provides breaker health information by monitoring and analyzing theoperation count, arcing energy of breaking current, arcing time, tripping time, closing timeand spring charging time if applicable. The breaker health status depends on manyfactors, such as permissible operation number, magnitude of breaking current, mechanicalwear and contact wear.The operation count is able to give direct information by comparing it with the permissibleoperation number. The longer tripping time and closing time can provide an approximateestimation of trip/close coils and mechanical wear. The increasing spring charging timemay imply developing problems in motor and spring mechanisms. Meanwhile, theincrease in arcing energy of the breaking current may reflect the possibility of contactwear. Longer arcing time may suggest the loss of dielectric strength in the arc chamber. Ifthe arcing energy or any of the time intervals is above the related Pickup levels for the use-defined times, the ALARM LED is lit.The scheme is equipped with three incomplete sequence timers for Trip/Close time, arctime and spring charge time respectively. So it automatically resets the related timeinterval after the programmed delay.A breaker operation function is also included, where breaker operation failure is caused byeither of the following conditions:• The breaker does not respond to a Trip command within the programmed breakeroperation delay time.• The breaker does not respond to a Close command within the programmed time.Path: Setpoints > Monitoring > Breaker 1 > Breaker HealthFUNCTIONRange: Disabled, Alarm, Latched Alarm, ConfigurableDefault: DisabledMODERange: Detection, MonitoringDefault: DetectionThe Breaker Health has two running modes: detection and monitoring. Since themonitored time intervals differ for different breaker types and manufacturers, thedetection mode can be used to help users set the Pickup settings based on the historicaltrue values. The operation count, arcing energy of the breaking current, arcing time,tripping time, closing time and spring charging time are measured and displayed in‘Records/Breaker Health,’ But the element does not pick up when in detection mode.Monitoring mode is the normal mode, wherein measurements are analyzed and theelement may pick up accordingly.PRESET TRIP COUNTERRange: 0 to 100000 in steps of 1Default: 0This setting pre-sets the actual operation number when the relay is starting in service orthe record is cleared.TRIP TRIGGERRange: Off, Any FlexLogic operandDefault: OffThis setting assigns the trip initiation signal.CLOSE TRIGGERRange: Off, Any FlexLogic operandDefault: OffThis setting assigns the close initiation signal.
