Figure. 5.3.9 - 109. Retrip and CBFP when "Current or DO" is the selected criterion.
When the current threshold setting of
I
set
and/or
I0
set
is exceeded, or the TRIP signal reaches the
primary protection stage, the function starts counting down towards the RETRIP and CBFP
signals. The tripping of the primary protection stage is constantly monitored in this configuration
regardless of the current's status. The pick-up of the CBFP is active unless the current is reduced
below the setting limit and the primary stage tripping signal is reset. If either of these conditions is met
(i.e. the current is above the limit or the signal is active) for the duration of the set RETRIP time delay, a
RETRIP signal is sent to the redundant trip coil. If either of the conditions is active for the duration of the
set CBFP time delay, a CBFP signal is sent to the incomer breaker. If the primary protection function
clears the fault, both counters (RETRIP and CBFP) are reset as soon as the measured current is below
the threshold settings and the tripping signal is reset. This configuration allows the CBFP to be
controlled with current-based functions alone, with added security from current monitoring. Other
function trips can also be included in the CBFP functionality.
A
AQ
Q-F215
-F215
Instruction manual
Version: 2.04
162
