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Phase Current Differential (87) Protection BE1-11m
Flux-Balancing Configuration
In a flux-balancing arrangement, the phase and neutral side of each phase of the winding route through a
CT so the net flux is zero under normal conditions. See Figure 15-4. Typically, a three-phase
Instantaneous Overcurrent (50) element provides flux-balancing protection.
Figure 15-4. Flux-Balancing Connections
If a BE1-11m is equipped with the differential option, an alternate method can be used to configure flux-
balancing protection. In the Phase Differential (87) window of BESTCOMSPlus, set the mode to Flux
Balance. In this mode, the BE1-11m compares the setting in the Flux Balance Pickup setting (secondary
A) on a per-phase basis to the current in CT circuit 1 (CT1). The link between CT1 and the Flux Balance
mode is fixed in firmware; the flux balance circuit must be wired to CT circuit 1 (terminals D1 through D8
in Figure 15-4). The “Flux Balance” mode is equivalent to a three-phase 50 element.