ABB Relion 611 Series, Technical Manual

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GUID-61D73737-798D-4BA3-9CF2-56D57719B03D V4 EN
Figure 146: Start logic
Timer 1
Once activated, the timer runs until the set Retrip time value has elapsed. The time
characteristic is according to DT. When the operation timer has reached the value set
with
Retrip time , the retrip logic is activated. A typical setting is 0...50 ms.
Timer 2
Once activated, the timer runs until the set CB failure delay value has elapsed. The
time characteristic is according to DT. When the operation timer has reached the set
maximum time value
CB failure delay , the backup trip logic is activated. The value of
this setting is made as low as possible at the same time as any unwanted operation is
avoided. A typical setting is 90 - 150 ms, which is also dependent on the retrip timer.
The minimum time delay for the CB failure delay can be estimated as:
CBfailuredelay Retriptime t t t
cbopen BFP reset margin
≥ + + +
_
A070693 V3 EN
(Equation 32)
t
cbopen
maximum opening time for the circuit breaker
t
BFP_reset
maximum time for the breaker failure protection to detect the correct breaker function (the
current criteria reset)
t
margin
safety margin
Section 5
1MRS757454 D
Protection related functions
310 611 series
Technical Manual