9.5
Date Code 20100129
Instruction Manual
SEL-751A Relay
Analyzing Events
Event Reporting
The event type designations AG through CAG in
are only entered in
the
Event
field if the fault type is determined successfully.
Currents, Voltages, and RTD Temperatures
The
Current
Mag
fields display the primary current magnitudes at the instant
the TRIP Relay Word bit asserted or the ER equation asserted. The currents
displayed are listed below:
➤
Line Currents (IA, IB, IC)
➤
Neutral Current (IN)
➤
Residual Current (IG), calculated from IA, IB, IC
The
Voltage
Mag
fields display the primary voltage magnitudes at the instant
the TRIP Relay Word bit asserts or the ER equation asserts. The voltages
displayed are listed below:
➤
DELTA_Y := WYE
➢
Phase-to-Neutral Voltages (VAN, VBN, VCN)
➢
Residual Voltage VG, calculated from VA, VB, VC
➤
DELTA_Y := DELTA
➢
Phase-to-Phase Voltages (VAB, VBC, VCA)
If the RTDs are connected, the hottest RTD (°C) fields display the hottest RTD
reading in each RTD group. The hottest RTD temperatures in degrees
centigrade (°C) are listed below:
➤
Winding
➤
Bearing
➤
Ambient
➤
Other
Event History
The event history report gives you a quick look at recent relay activity. The
relay labels each new event in reverse chronological order with
1
as the most
recent event. See
for a sample event history. Use this report to view
the events that are presently stored in the SEL-751A.
The event history contains the following:
➤
Standard report header
➢
Relay and terminal identification
➢
Date and time of report
➢
Time source (if IRIG-B model)
➤
Event number, date, time, event type (see
)
ER Trigger
ER Equation assertion. Phase involvement is indetermi-
nate.
Trip
TRIP with no known cause
a
ABG, BCG, and CAG detection requires at least one of the 50G or 51G elements to be enabled
and picked up (GFLT = 50G1 + 50G2+ 50G3 + 50G4 + 51G1 + 51G2 = 1). Overcurrent trip
includes all 50/51 P, Q, N, or G elements.
Table 9.1
Event Types
(Sheet 2 of 2)
Event Type
Event Type Logic
Summary of Contents for 751A
Page 1: ...20100129 SEL 751A Feeder Protection Relay Instruction Manual PM751A 01 NB...
Page 6: ...This page intentionally left blank...
Page 12: ...This page intentionally left blank...
Page 18: ...This page intentionally left blank...
Page 26: ...This page intentionally left blank...
Page 92: ...This page intentionally left blank...
Page 218: ...This page intentionally left blank...
Page 250: ...This page intentionally left blank...
Page 376: ...This page intentionally left blank...
Page 392: ...This page intentionally left blank...
Page 408: ...This page intentionally left blank...
Page 418: ...This page intentionally left blank...
Page 434: ...This page intentionally left blank...
Page 462: ...This page intentionally left blank...
Page 544: ...This page intentionally left blank...
Page 580: ...This page intentionally left blank...
Page 584: ...This page intentionally left blank...
Page 632: ...This page intentionally left blank...
Page 636: ...This page intentionally left blank...
Page 640: ...This page intentionally left blank...