CHAPTER 7: PROTECTION GROUPED PROTECTION ELEMENTS
D90
PLUS
LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL 283
Breaker Position 1 Phase B
Range: any FlexLogic operand or shared operand
Default: Off
This setting selects the operand to represent the protected breaker early-type auxiliary
switch contact on pole B. This contact is normally a non-multiplied form-A contact. The
contact can even be adjusted to have the shortest possible operating time. This setting
is valid only for single-pole breaker failure schemes.
Breaker Position 1 Phase C
Range: any FlexLogic operand or shared operand
Default: Off
This setting selects the operand to represent the protected breaker early-type auxiliary
switch contact on pole C. This contact is normally a non-multiplied form-A contact. The
contact can even be adjusted to have the shortest possible operating time. This setting
is valid only for single-pole breaker failure schemes.
Breaker Position 2 Phase B
Range: any FlexLogic operand or shared operand
Default: Off
This setting selects the operand that represents the protected breaker normal-type
auxiliary switch contact on pole B (52/a). This can be a multiplied contact. This setting is
valid only for single-pole breaker failure schemes.
Breaker Position 2 Phase C
Range: any FlexLogic operand or shared operand
Default: Off
This setting selects the operand that represents the protected breaker normal-type
auxiliary switch contact on pole C (52/a). This can be a multiplied contact. For single-pole
operation, the scheme has the same overall general concept except that it provides re-
tripping of each single pole of the protected breaker. The approach shown in the
following single pole tripping diagram uses the initiating information to determine which
pole is supposed to trip. The logic is segregated on a per-pole basis. The overcurrent
detectors have ganged settings. This setting is valid only for single-pole breaker failure
schemes.
Upon operation of the breaker failure element for a single pole trip command, a three-
pole trip command needs to be given via the BKR FAIL 1 TRIP OP output operand.
The figures show the logic for the breaker failure element. The logic is identical for both
breaker failure elements.
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