distance relay 7sa611

[Eng. Ahmed el mawee]

please help for testing the broken conductor for 7sa611 (adress 195 conductor fail )

[الطيب الطيب]

السلام عليكم و رحمة الله و بركاته

Current Symmetry: During normal system operation, symmetry among the input currents is expected. The
symmetry is monitored in the device by magnitude comparison. The smallest phase
current is compared to the largest phase current. Asymmetry is recognized if:
|Imin | / | Imax | < BAL. FACTOR I as long as Imax / IN > BALANCE I LIMIT / IN
Thereby Imax is the largest of the three phase currents and Imin the smallest. The symmetry
factor BAL. FACTOR I represents the allowable asymmetry of the phase currents
while the limit value BALANCE I LIMIT is the lower limit of the operating range
of this monitoring (see Figure 2-172). Both parameters can be set. The resetting ratio
is about 97% .
After a settable time (5-100 s) this malfunction is signalled as „Fail I balance“
(No. 163).