13.14
SEL-311C Relay Instruction Manual Date Code 20060320
Testing and Troubleshooting
Relay Testing
Output Contact
Explanation
OUT1 and OUT2 are set to close for trips. The relay is set to trip instantaneously
for Zone 1 faults, with a short time delay for Zone 2 faults, and by operation of
the residual and negative-sequence time-overcurrent elements. OUT4 is set to
close for assertion of the KEY element. The KEY element is used in
Permissive Overreaching Transfer Tripping protection schemes to send the
permissive signal to the remote end. The SEL-311C asserts the KEY element
when overreaching Zone 2 elements pick up, if other conditions permit.
Target LED
Explanation
The TRIP target illuminates at the rising edge of trip (the new assertion of the
TRIP Relay Word bit).
The TIME target illuminates at the rising edge of trip if the SEL
OGIC
®
control
equation FAULT has been asserted for more than three cycles.
The Zone targets indicate the zone or level of the element that caused the trip.
The A, B, C, and G targets indicate the phase involvement.
The COMM and SOTF targets indicate when the trip occurred as part of a
Communications-based operation or a Switch-Onto-Fault operation,
respectively.
Section 5: Trip and Target Logic includes detailed information regarding
operation of the relay targets.
Front-Panel LCD
Explanation
The relay generates an event report for each fault. To see the summary event
report for the last fault:
Step 1. Press the {EVENT} pushbutton on the relay front panel and use
the Up, Down, Left, and Right arrow pushbuttons to review the
information presented there.
Step 2. If a new fault occurs while you are reviewing the fault data,
press the {EXIT} pushbutton, then the {EVENT} pushbutton to
review the new data.
Step 3. You may review the long form event report for each fault by
using a terminal connected to one of the relay serial ports.
Each event report is a record of the currents, voltages, relay
element states, and logic input and contact output states.
Step 4. See Section 12: Standard Event Reports and SER for further
details on the retrieval and analysis of event reports saved by
this relay.
NOTE: The POTT scheme is not
available in the SEL-311B and SEL-311A
relays.
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