Siemens SIRIUS 3RT Series System Manual page 720

SIRIUS 3RR2 current monitoring relays
8.8 Operation
Tripping delay time
Definition of tripping delay time (Del)
The set tripping delay time starts when the monitoring current overshoots or undershoots the
corresponding set threshold value.
Explanation
The set tripping delay time starts when the load current flowing under normal operating
conditions overshoots or undershoots the corresponding set threshold value. The symbols
for the CO contact and/or the semiconductor output flash. Once this time has elapsed, if the
current value has not returned to the correct range, the CO contact and the semiconductor
output will change the switching state in accordance with the selected circuit principle.
Note
Special cases wire break/phase failure (incorrect phase sequence/fault current/blocking
current)
When a wire break or phase failure is detected, as well as in the event of incorrect phase
sequence, fault current, and blocking current (if these have been activated), a delay time is
not observed. The current monitoring relay responds immediately (≤ 200 ms) in such cases.
Setting range
The setting range for the tripping delay time is 0 s to 30 s. The increment is 1 s.
Factory setting
The tripping delay time is factory-set to 0 s.
Changes to settings
Changes to the tripping delay time can be made using the arrow keys. Press and hold down
the keys to speed up this process.
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SIRIUS Innovations
System Manual, 01/2011, A8E56203870002-03