السلام عليكم و رحمة الله و بركاتهCurrent 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).
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