5-178 B90 LOW IMPEDANCE BUS DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL
GROUPED ELEMENTS CHAPTER 5: SETTINGS
5
EFP1 PICKUP DELAY — This setting allows extra security when tripping the bus from the EFP element. This timer shall be set
longer than the maximum delay between the breaker closing and picking up some current and the
EFP MANUAL CLOSE
signal. If the manual close signal, EFP MANUAL CLOSE, arrives before the timer expires, the element resets and misoperation
due to signal transit times is avoided.
EFP1 BLOCK — This setting dynamically block/unblocks the element. A typical application is a by-pass isolator as shown
below. When the isolator is closed, the current does not necessarily indicate on a fault between the CB and CT and the
element 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 isolators
Figure 5-95: End fault protection logic
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