5-134 F35 Multiple Feeder Protection System GE Multilin5.6 GROUPED ELEMENTS 5 SETTINGS55.6GROUPED ELEMENTS 5.6.1 OVERVIEWEach protection element can be assigned up to six different sets of settings according to setting group designations 1 to 6.The performance of these elements is defined by the active setting group at a given time. Multiple setting groups allow theuser to conveniently change protection settings for different operating situations (for example, altered power system config-uration, season of the year, etc.). The active setting group can be preset or selected via the SETTING GROUPS menu (see theControl elements section later in this chapter). See also the Introduction to elements section at the beginning of this chap-ter.5.6.2 SETTING GROUPPATH: SETTINGS GROUPED ELEMENTS SETTING GROUP 1(6)Each of the six setting group menus is identical. Setting group 1 (the default active group) automatically becomes active ifno other group is active (see the Control elements section for additional details).5.6.3 PHASE CURRENTa) INVERSE TIME OVERCURRENT 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 none of these curve shapes is adequate, FlexCurves may be used to customize the inverse time curve characteristics.The definite time curve 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 energy capacity 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: “Instantaneous” and “Timed”. The “Instan- SETTING GROUP 1 PHASE CURRENT See below.MESSAGE NEUTRAL CURRENT See page 5-142.MESSAGE WATTMETRIC GROUND FAULT See page 5-144.MESSAGE GROUND CURRENT See page 5-148.MESSAGE NEGATIVE SEQUENCE CURRENT See page 5-150.MESSAGE VOLTAGE ELEMENTS See page 5-152.Table 5–16: OVERCURRENT CURVE TYPESIEEE IEC GE TYPE IAC OTHERIEEE Extremely Inverse IEC Curve A (BS142) IAC Extremely Inverse I2 tIEEE Very Inverse IEC Curve B (BS142) IAC Very Inverse FlexCurves A, B, C, and DIEEE Moderately Inverse IEC Curve C (BS142) IAC Inverse Recloser CurvesIEC Short Inverse IAC Short Inverse Definite Time
