GE Multilin G60 Generator Management Relay 5-895 SETTINGS 5.5 GROUPED ELEMENTS55.5.6 PHASE CURRENTa) MAIN MENUPATH: SETTINGS " GROUPED ELEMENTS ! SETTING GROUP 1(6) !" PHASE CURRENTb) INVERSE TOC CURVE CHARACTERISTICSThe inverse time overcurrent curves used by the time overcurrent elements are the IEEE, IEC, GE Type IAC, and I 2 t stan-dard curve shapes. This allows for simplified coordination with downstream devices. If however, none of these curveshapes is adequate, FlexCurvesô may be used to customize the inverse time curve characteristics. The Definite Timecurve is also an option that may be appropriate if only simple protection is required.A time dial multiplier setting allows selection of a multiple of the base curve shape (where the time dial multiplier = 1) withthe curve shape (CURVE) setting. Unlike the electromechanical time dial equivalent, operate times are directly proportionalto the time multiplier (TD MULTIPLIER) setting value. For example, all times for a multiplier of 10 are 10 times the multiplier 1or base curve values. Setting the multiplier to zero results in an instantaneous response to all current levels above pickup.Time overcurrent time calculations are made with an internal ëenergy capacityí memory variable. When this variable indi-cates that the energy capacity has reached 100%, a time overcurrent element will operate. If less than 100% energy capac-ity is accumulated in this variable and the current falls below the dropout threshold of 97 to 98% of the pickup value, thevariable must be reduced. Two methods of this resetting operation are available: ìInstantaneousî and ìTimedî. The ìInstan-taneousî selection is intended for applications with other relays, such as most static relays, which set the energy capacitydirectly to zero when the current falls below the reset threshold. The ìTimedî selection can be used where the relay mustcoordinate with electromechanical relays.Graphs of standard time-current curves on 11î × 17î log-log graph paper are available upon request fromthe GE Multilin literature department. The original files are also available in PDF format on the enerVista CDand the GE Multilin website at http://www.GEindustrial.com/multilin.# PHASE CURRENT## PHASE TOC1# See page 5ñ94.MESSAGE # PHASE IOC1# See page 5ñ96.MESSAGE # PHASE IOC2# See page 5ñ96.MESSAGE # PHASE# DIRECTIONAL 1 See page 5ñ97.Table 5ñ9: OVERCURRENT CURVE TYPESIEEE IEC GE TYPE IAC OTHERIEEE Extremely Inv. IEC Curve A (BS142) IAC Extremely Inv. I2 tIEEE Very Inverse IEC Curve B (BS142) IAC Very Inverse FlexCurvesô A, B, C, and DIEEE Moderately Inv. IEC Curve C (BS142) IAC Inverse Recloser CurvesIEC Short Inverse IAC Short Inverse Definite TimeNOTE
