5-320 L60 LINE PHASE COMPARISON SYSTEM – INSTRUCTION MANUALCONTROL ELEMENTS CHAPTER 5: SETTINGS5The broken conductor function detects a transmission line broken conductor condition or a single-pole breakermalfunction condition by checking the phase current input signals and the I_2 / I_1 ratio. The intent is to detect a single-phase broken conductor only. As such, two-phase or three-phase broken conductors cannot be detected.To distinguish between single-phase disappearance and system disturbance in all three phases (such as load change andswitching), the broken conductor element monitors the change in all three phase currents at the present instance and atfour cycles previous. It also monitors changes in the I_2 / I_1 ratio, I_1 minimum, and I_1 maximum.Do not use the broken conductor function to respond to fault transients and single-pole tripping/reclosing conditions.Therefore, program the time delay to a sufficient length to ensure coordination with the breaker dead time of the recloserfunction.BROKEN CONDUCTOR 1 FUNCTION — This setting enables and disables the broken conductor function.BROKEN CONDUCTOR 1 SOURCE — Selects a signal source used to provide three-phase current inputs to this function.BROKEN CONDUCTOR 1 I2/I1 RATIO — This setting specifies the ratio of negative-sequence current to positive-sequencecurrent. When one phase conductor is broken, the I_2 / I_1 ratio with a balanced remaining two phases is 50%. Sonormally you this setting below 50% (for example, to 30%).BROKEN CONDUCTOR 1 I1 MIN — This setting specifies the minimum positive-sequence current supervision level. Ensure thissetting is programmed to a sufficient level to prevent I_2 / I_1 from erratic pickup due to a low I_1 signal. However, do notset this setting too high, since the broken conductor condition cannot be detected under light load conditions when I_1 isless than the value specified by this setting.BROKEN CONDUCTOR 1 I1 MAX — This setting specifies the maximum I_1 level allowed for the broken conductor function tooperate. When I_1 exceeds this setting, this it is considered a fault. In order for this function to not respond to any faultconditions, set this setting to less than the maximum load current.BROKEN CONDUCTOR 1 PKP DELAY — This setting specifies the pickup time delay for this function to operate after assertionof the broken conductor pickup FlexLogic operand. BROKEN CONDUCTOR 1I1 MAX: 1.50 puRange: 0.05 to 5.00 pu in steps of 0.01 BROKEN CONDUCTOR 1PKP DELAY: 20.000 sRange: 0.000 to 65.535 s in steps of 0.001 BROKEN CONDCT 1 BLK:OffRange: FlexLogic operand BROKEN CONDUCTOR 1TARGET: Self-resetRange: Self-reset, Latched, Disabled BROKEN CONDUCTOR 1EVENTS: DisabledRange: Disabled, Enabled
