2-18 Specifications Date Code 20011026
SEL-321/321-1 Instruction Manual
Input
Potential Transfer PTXFR Drive with potential transfer switch initiation
indication.
Output
Trip Suspicion TS Blocks all tripping conditions for 3 cycles.
Supporting Drawing: Figure 2.44.
Fault Identification Selection (FIDS) Logic
This logic identifies the faulted phase(s) for all faults involving ground by comparing the angle
between I
0
and I
2
.
The logic is not active during an SPO condition.
Outputs
FIDS Selects A-phase FSA Enables A-phase ground distance and blocks AB
and CA phase distance elements.
FIDS Selects B-phase FSB Enables B-phase ground distance and blocks AB and
BC phase distance elements.
FIDS Selects C-phase FSC Enables C-phase ground distance and blocks BC and
CA phase distance elements.
Open Phase Alarm Logic
This logic detects negative-sequence current in the presence of balanced voltages when all poles
of the breaker are closed. This condition asserts an alarm element labeled OPA.
Use a SEL
OGIC control equation to program OPA to an output contact for alarming.
Output
Open Pole Alarm Element OPA Indicates an open phase condition.
Supporting Drawing: Figure 2.45.
Contact Input Assignments
The one I/O board relay has eight assignable logic inputs IN1 - IN8. The two I/O board relay has
16 inputs, IN1 - IN16. You assign functions to each of the inputs from the assignments listed in
Table 2.4 by using the SET G command. The assigned input statuses are available in Relay
Word rows 20 - 23 (see Table 2.9).
To Next Page
Loading...
