CHAPTER 5: SETTINGS GROUPED ELEMENTSG30 GENERATOR PROTECTION SYSTEM – INSTRUCTION MANUAL 5-1775The non-volatile latches provide a permanent logical flag that is stored safely and do not reset upon restart after the relayis powered down. Typical applications include sustaining operator commands or permanently blocking relay functions,such as Autorecloser, until a deliberate interface action resets the latch.LATCH 1 TYPE — This setting characterizes Latch 1 to be Set- or Reset-dominant.LATCH 1 SET — If asserted, the specified FlexLogic operands 'sets' Latch 1.LATCH 1 RESET — If asserted, the specified FlexLogic operand 'resets' Latch 1.Figure 5-88: Non-volatile latch operation table (N = 1 to 16) and logic5.7 Grouped elements5.7.1 OverviewEach protection element can be assigned up to six sets of settings with designations 1 to 6. The performance of theseelements is defined by the active setting group at a given time. Multiple setting groups allow the user to convenientlychange protection settings for different operating situations (for example, altered power system configuration or season ofthe year). The active setting group can be preset or selected in the SETTING GROUPS menu (see the Control Elements sectionlater in this chapter). See also the Introduction to Elements section at the beginning of this chapter. LATCH 1 RESET:OffRange: FlexLogic operand LATCH 1TARGET: Self-resetRange: Self-reset, Latched, Disabled LATCH 1EVENTS: DisabledRange: Disabled, EnabledLatch n type Latch nsetLatch nresetLatch nonLatch noffResetDominantON OFF ON OFFOFF OFF PreviousStatePreviousStateON ON OFF ONOFF ON OFF ONSetDominantON OFF ON OFFON ON ON OFFOFF OFF PreviousStatePreviousStateOFF ON OFF ON
