11.16
SEL-751 Relay Instruction Manual Date Code 20170927
Testing and Troubleshooting
Troubleshooting
Troubleshooting
Clock Chip
Unable to communicate with clock or
fails time keeping test
No Not
Latched
Yes NA
STA C, to clear
the warning in the
status report.
Contact SEL if
failure returns.
Clock Chip RAM
Clock chip static RAM fails
No Not
Latched
Yes NA
STA C, to clear
the warning in the
status report.
Contact SEL if
failure returns.
External RTD
Fail if no comm, or the external RTD
module reports open RTDs, shorted
RTDs, a power supply failure
NA NA No RTD Failure
STA C, to clear
the warning in the
status report.
Contact SEL if
failure returns.
CID (Configured IED Description) file
(access)
Failure to Access/Read CID File
No NA No Status Fail
CID File Failure
Exception Vector
CPU Error
Yes Latched NA Vector nn
Relay Disabled
Automatic restart.
Contact SEL if
failure returns.
Ta b l e 1 1 . 8 Re l ay S e l f-Tes t s (Sheet 3 of 3)
Self-Test Description
Normal
Range
Protection
Disabled
on Failure
Alarm
Status
Auto
Message
on Failure
Front Panel
Message
on Failure
Corrective
Action
Table 11.9 Troubleshooting (Sheet 1 of 2)
Symptom/Possible Cause Diagnosis/Solution
The relay ENABLED front-panel LED is dark.
Input power is not present or a fuse is blown. Verify that input power is present.
Check fuse continuity.
Self-test failure View the self-test failure message on the front-panel display.
The relay front-panel display does not show characters.
The relay front-panel has timed out. Press the ESC pushbutton to activate the display.
The relay is de-energized. Verify input power and fuse continuity.
The relay does not accurately measure voltages or currents.
Wiring error Verify input wiring.
Incorrect CTR, CTRN, or PTR setting Verify instrument transformer ratios, connections, and associated
settings.
Voltage neutral terminal (N) is not properly grounded. Verify wiring and connections.
To Next Page
Loading...
