2 Functions
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7SD610 Manual
C53000-G1176-C145-4
Figure 2-69 Initiation conditions for single-pole trip commands
Delay times When the initiate conditions are fulfilled, the associated timers are started. The circuit
breaker pole(s) must open before the associated time has elapsed.
Different delay times are possible for single-pole and three-pole initiation. An addition-
al delay time can be used for two-stage breaker failure protection.
With single-stage breaker failure protection
, the trip command is routed to the adjacent
circuit breakers which then interrupt the fault current if the local feeder breaker fails
(Figure 2-61 or Figure 2-62). Adjacent circuit breakers are the ones of the busbar or
busbar section to which the considered feeder is connected. The possible initiation
conditions for the breaker failure protection are those discussed above. Depending on
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