![Schweitzer Engineering Laboratories SEL-421-4 Instruction Manual Download Page 1117](http://html.mh-extra.com/html/schweitzer-engineering-laboratories/sel-421-4/sel-421-4_instruction-manual_12167261117.webp)
10.21
Date Code 20171006
Instruction Manual
SEL-400 Series Relays
Testing, Troubleshooting, and Maintenance
Relay Troubleshooting
Line Current Differential Warnings
87L Watchdog Alarm
This alarm indicates that the relay has received more than three unwarranted 87L pickup opera-
tions associated with 87L communication channel impairments. This logic asserts Relay Word
bit 87ALARM and does not inhibit 87L protection. This alarm can be reset at Access Level 2 by
issuing a
COM 87L WD C
command.
87L Watchdog Error 1
This error indicates that the relay has received more than five unwarranted 87L pickup opera-
tions associated with 87L communication channel impairments. This logic asserts Relay Word
bit 87ERR1 and inhibits 87L protection. This alarm can be reset at Access Level 2 by issuing a
COM 87L WD C
command.
87L Watchdog Error 2
This error indicates that the relay has received more than ten unwarranted 87L pickup opera-
tions associated with 87L communications channel impairments and non-channel related issues.
This logic asserts Relay Word bit 87ERR2 and inhibits 87L protection. This alarm can be reset
at Access Level 2 by issuing a
COM 87L WD C
command.
NOTE:
In firmware R105 and older, this alarm can only be reset at Access Level C.
87L Watchdog Reset
This warning occurs when the
COM 87L WD C
command is issued.
Hardware Changes
Card or Board Change
This indicates that the installed hardware does not match the part number. If the hardware was
intentionally changed, use the
STA
command from Access Level 2 to accept the new hardware
configuration. If the hardware was not changed, make sure all connections are fully seated and
then restart the relay. If the error persists, contact the SEL factory or your Technical Service
Center.
Power Supply Voltage Status Warning
Power supply voltage(s) are out-of-
tolerance.
Log the Status Warning. If repeated warnings occur, take preventive action.
A/D converter failure.
LCD displays
STATUS FAILURE
screen. Contact the SEL factory or your Technical Service
Center.
Power Supply Voltage Status Failure
Power supply voltage(s) are out-of-
tolerance.
LCD displays
STATUS FAILURE
screen. Contact the SEL factory or your Technical Service
Center.
A/D OFFSET WARN Status Warning
Loose ribbon cable between the input
module board and the main board.
Reseat both ends of the analog input cable.
A/D converter drift.
Log the Status Warning. If repeated warnings occur, contact the SEL factory or your Technical
Service Center.
Master offset drift.
LCD displays
STATUS FAILURE
screen. Contact the SEL factory or your Technical Service
Center.
FPGA Failure
FPGA diagnostics failed during either
power up or run time.
a
In this rare event, the relay will automatically restart. If the failure occurs three times in seven
days, the LCD displays the FPGA FAIL screen. Contact the SEL factory or your Technical Ser-
vice Center.
NOTE:
In older firmware versions, the relay did not automatically restart. Contact the SEL factory or
your Technical Service Center.
Serial Port Power Overload
+5V EIA-232 Overload
The relay rear serial ports are capable of pro5V power to an external transceiver, but
have a limited power output. This warning indicates that the power limit has been exceeded and
the current has been limited. Check what is connected to the serial ports to ensure that there is
no unintentional load on the +5V outputs.
All Other Warnings and Failures
Contact the SEL factory or your Technical Service Center.
a
The relay will automatically restart for some of these failures. Contact the factory if the failure recurs.
Table 10.7
Troubleshooting for Relay Self-Test Warnings and Failures (Sheet 2 of 2)
Diagnostic Message
Diagnosis/Solution
Summary of Contents for SEL-421-4
Page 6: ...This page intentionally left blank ...
Page 14: ...This page intentionally left blank ...
Page 30: ...This page intentionally left blank ...
Page 104: ...This page intentionally left blank ...
Page 128: ...This page intentionally left blank ...
Page 536: ...This page intentionally left blank ...
Page 584: ...This page intentionally left blank ...
Page 616: ...This page intentionally left blank ...
Page 696: ...This page intentionally left blank ...
Page 750: ...This page intentionally left blank ...
Page 755: ...Instruction Manual PM400 01 NB SEL 400 Series Relays Instruction Manual 20171006 ...
Page 776: ...This page intentionally left blank ...
Page 932: ...This page intentionally left blank ...
Page 976: ...This page intentionally left blank ...
Page 1024: ...This page intentionally left blank ...
Page 1038: ...This page intentionally left blank ...
Page 1064: ...This page intentionally left blank ...
Page 1128: ...This page intentionally left blank ...
Page 1206: ...This page intentionally left blank ...
Page 1316: ...This page intentionally left blank ...
Page 1350: ...This page intentionally left blank ...
Page 1464: ...This page intentionally left blank ...
Page 1468: ...This page intentionally left blank ...
Page 1492: ...This page intentionally left blank ...
Page 1518: ...This page intentionally left blank ...