5-258 F60 Feeder Protection System GE Multilin5.7 CONTROL ELEMENTS 5 SETTINGS5Figure 5–129: BROKEN CONDUCTOR DETECTION LOGICi) THERMAL OVERLOAD PROTECTIONPATH: SETTINGS CONTROL ELEMENTS MONITORING ELEMENTS THERMAL OVERLOAD PROTECTION THERMALPROTECTION 1(2)The thermal overload protection element corresponds to the IEC 255-8 standard and is used to detect thermal overloadconditions in protected power system elements. Choosing an appropriate time constant element can be used to protect dif-ferent elements of the power system. The cold curve characteristic is applied when the previous averaged load current overthe last 5 cycles is less than 10% of the base current. If this current is greater or equal than 10% than the base current, thenthe hot curve characteristic is applied. THERMAL PROTECTION 1THERMAL PROTECTION 1FUNCTION: DisabledRange: Disabled, EnabledMESSAGE THERMAL PROTECTION 1SOURCE: SRC1Range: SRC 1, SRC 2MESSAGE THERMAL PROTECTION 1BASE CURR: 0.80 puRange: 0.20 to 3.00 pu in steps of 0.01MESSAGE THERMAL PROTECTION 1k FACTOR: 1.10Range: 1.00 to 1.20 in steps of 0.05MESSAGE THERM PROT 1 TRIPTIME CONST: 45 min.Range: 0 to 1000 min. in steps of 1MESSAGE THERM PROT 1 RESETTIME CONST: 45 min.Range: 0 to 1000 min. in steps of 1MESSAGE THERM PROT 1 MINIMRESET TIME: 20 min.Range: 0 to 1000 min. in steps of 1MESSAGE THERM PROT 1 RESET:OffRange: FlexLogic operandMESSAGE THERM PROT 1 BLOCK:OffRange: FlexLogic operandMESSAGE THERMAL PROTECTION 1TARGET: Self-resetRange: Self-reset, Latched, DisabledMESSAGE THERMAL PROTECTION 1EVENTS: DisabledRange: Disabled, EnabledSETTINGSBROKEN CONDUCTOR 1FUNCTION:Enabled = 1ANDBROKEN CONDCT 1 BLK:Off = 0SETTINGSBROKEN CONDUCTOR 1SOURCE:I2FLEXLOGIC OPERANDBROKEN CONDUCT 1 OPI1IaIbIcANDSETTINGBROKEN CONDUCTOR 1I1 MIN :| I1 | > I1 MIN| Ia | < I1 MIN| Ib | < I1 MIN| Ic | < I1 MIN| Ia’ | - | Ia | > 0.05pu| Ib’ | - | Ib | > 0.05pu| Ic’ | - | Ic | > 0.05puWhere I’ is 4 cycles oldANDANDOROne phase current lossdetectionRUN2 cyc0ANDORSETTINGBROKEN CONDUCTOR 1I1 MAX :RUN| I1 | < I1 MAX| I2 | / | I1 |> RATIOBROKEN CONDUCTOR 1I2/I1 RATIO :tPKP0SETTINGBROKEN CONDUCTOR 1I1 MAX :FLEXLOGIC OPERANDBROKEN CONDUCT 1 PKP
