ABB RELION REX640 Technical Manual page 454

Section 4
Protection functions
448
GUID-A81838E7-95A2-49CA-BC6B-786025D1D12E V1 EN
Figure 241: Example of INTRPTEF operation in "Transient EF" mode in the faulty
feeder
In the "Intermittent EF" mode the OPERATE output is activated when the following
conditions are fulfilled:
• the number of transients that have been detected exceeds the Peak counter limit
setting
• the timer has reached the time set with the Operate delay time
• and one additional transient is detected during the drop-off cycle
The Reset delay time starts to elapse from each detected transient (peak). In case there
is no OPERATE activation, for example, the fault disappears momentarily START
stays activated until the Reset delay time elapses, that is, reset takes place if time
between transients is more than Reset delay time. After OPERATE activation, a fixed
pulse length of 100 ms for OPERATE is given, whereas START is reset after Reset
delay time elapses
1MRS759142 C
REX640
Technical Manual