ABB REG316 4 Series Operating Instructions Manual page 327

REG 316*4 1MRB520049-Uen / Rev. F
Tripping delay tEFP
The setting for tEFP can be seen from Fig. 3.5.28.2 which shows
a typical timing diagram for tripping a fault.
CB
tripping signal (1)
Fig. 3.5.28.2
(1) Tripping command applied to the CB.
(2) CB auxiliary contact sends a signal that the CB is open to
the "CB Off" input of the function which is used to start the
EFP.
(3) The circuit-breaker ruptures the fault current.
(4) After a reset delay plus a safety margin, the current unit ei-
ther detects that the fault current has been interrupted and
the EFP function resets, or the fault current continues to
flow and an EFP signal is issued.
tEFP
t
CB open
t
CB Off
t
Reset
t
Margin
3)
see reset time of the current detector t
4)
see Margin time t
Margin
CB
open (3) tripping signal (4)
t
CB open
t + t
Reset
t
tEFP
CB Off
CB
tripped (2)
Timing diagram for an end zone fault
³ - +
t t
CB open CB Off
CB opening time including arc extinction time
CB opening time of the CB auxiliary contact
(Signal „CB open")
Reset time of the current detector
Allowance for variations in normal fault clearing time
Reset
EFP
Margin
t + t
Margin
Reset
3)
ABB Switzerland Ltd
4)
3-289