5-178 B90 LOW IMPEDANCE BUS DIFFERENTIAL SYSTEM – INSTRUCTION MANUALGROUPED ELEMENTS CHAPTER 5: SETTINGS5EFP1 PICKUP DELAY — This setting allows extra security when tripping the bus from the EFP element. This timer shall be setlonger than the maximum delay between the breaker closing and picking up some current and the EFP MANUAL CLOSEsignal. If the manual close signal, EFP MANUAL CLOSE, arrives before the timer expires, the element resets and misoperationdue to signal transit times is avoided.EFP1 BLOCK — This setting dynamically block/unblocks the element. A typical application is a by-pass isolator as shownbelow. When the isolator is closed, the current does not necessarily indicate on a fault between the CB and CT and theelement shall be blocked. Therefore, the close status of the isolator shall be used as the block setting.Figure 5-94: End fault protection and bypass isolatorsFigure 5-95: End fault protection logic
