GE F60 Instruction Manual

Also see for F60: Communications manual Communications guide Instruction manual Instruction manual Instruction manual

Contents

CHAPTER 5: SETTINGS MONITORING ELEMENTSF60 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL 5-2855Two FlexLogic operands, HI-Z ARMED and HI-Z DISARMED, are created to represent the armed state of the Hi-Z element. TheHI-Z ARMED operand is on when the algorithm is in the armed state, whereas the HI-Z DISARMED operand is on when thealgorithm is not in the armed state. When the algorithm is armed, this also includes the arcing and downed conductorstates. When the algorithm is disarmed, this also includes the normal and coordination timeout states (as defined byModbus format F187 as described in the Modbus memory map in the UR Series Communications Guide).The Hi-Z settings are as follows.HI-Z SOURCE — Selects the source for the RMS currents and voltages used in Hi-Z algorithms. The source should includecurrents from the 8F/8G CT module and appropriate voltages. If the source does not include voltages, Voltage Supervisionis disabled.HI-Z ARCING SENSITIVITY — Establishes the belief-in-arcing confidence level at which the Hi-Z element recognizes arcingand the number of times the algorithm must conform its belief in arcing before it produces an output. The range is 1 to 10,where 10 is the most sensitive and 1 is the least sensitive setting.A higher setting is suitable for a very quiet, well-behaved power system. An initial setting of 5 is suggested if the user hasno previous experience with the Hi-Z element.HI-Z ARCING DET SOE RESET TIME — An ARCING DETECTED event is created upon the detection of arcing by the expert arcdetector algorithm. This setting defines the amount of time to hold creation of any new arcing detected events. Anysubsequent arcing detection during this time restarts the hold timer. An ARCING DETECTED DPO event is generated uponthe expiration of this reset time. The state of the expert arc detector algorithm is unaffected by this timer. The HI-Z ARCDETECTED DPO operand is set to “On” when the ARCING DETECTED DPO event is created, and remains on until an ARCINGDETECTED event is created.HI-Z PHASE EVENT COUNT — Specifies how many individual belief-in-arcing indications for a phase current must be countedin a specified time period before it is determined that an arcing-suspected event exists. These belief-in-arcing indicationsare detected by arc detection algorithms (energy and randomness) for a specific set of non-fundamental frequencycomponent energies. This setting affects only the Hi-Z Arcing Suspected outputs.HI-Z GROUND EVENT COUNT — Specifies how many individual belief-in-arcing indications for a ground/neutral current mustbe counted in a specified time period before it is determined that an arcing-suspected event exists. These belief-in-arcingindications are detected by arc detection algorithms (energy and randomness) for a specific set of non-fundamentalfrequency component energies. This setting affects only the Hi-Z Arcing Suspected outputs.HI-Z EVENT COUNT TIME — Specifies the time (in minutes) over which the relay monitors long-term, sporadic, arcing eventsfor determination of an arcing-suspected event. This setting affects only the Hi-Z Arcing Suspected outputs.HI-Z OC PROTECTION COORD TIMEOUT — Coordinates between the Hi-Z element and conventional feeder overcurrentprotection. A downed conductor or an arcing, intact conductor is not indicated before the expiration of this timeout, whichbegins when the Hi-Z element detects a trigger condition (such as loss of load, high rate of change, overcurrent, breakeropen, or high belief-in-arcing confidence). Note that this is a minimum operating time; the actual operating time dependson the fault characteristics and is likely significantly longer than this setting.Set the value such that the conventional feeder overcurrent protection is given an opportunity to operate before thetimeout expires. It is recommended that this timeout value not exceed 30 seconds, because arcing fault current oftendiminishes as the fault progresses, making the fault more difficult to detect with increasing time. After the timeout hasexpired, at least one additional arc burst must occur in order for the Hi-Z element to proceed with its analysis.HI-Z PHASE OC MIN PICKUP — Phase overcurrent minimum pickup indicates the level at which the Hi-Z element considers aphase current to be an overcurrent condition. The Hi-Z detection algorithms ignore all data as long as an overcurrentcondition exists on the system, because it is assumed that conventional feeder overcurrent protection clears anovercurrent fault. It is recommended that this setting be above the maximum load current.HI-Z NEUTRAL OC MIN PICKUP — Neutral overcurrent minimum pickup indicates the level at which the Hi-Z elementconsiders a neutral current to be an overcurrent condition. The Hi-Z detection algorithms ignore all data as long as anovercurrent condition exists on the system, because it is assumed that conventional feeder overcurrent protection clearsan overcurrent fault. It is recommended that this setting is above the maximum 3Io (residual) current due to unbalancedloading.