U.4.8
SEL-421/SEL-421-1 Relay
User’s Guide
Date Code 20020501
Basic Relay Operations
Changing the Default Passwords
Changing the Default Passwords
NOTE:
Perform the password-
change steps described in Changing
the Default Passwords–Terminal at the
end of this subsection.
It is extremely important that you change the factory default passwords
programmed in the SEL-421 Relay. Setting unique passwords for the relay
access levels increases the security of your substation and the power system.
This subsection begins with information on the access level/password system
in the SEL-421 Relay and includes an example of changing the default
passwords.
Access Levels
Access levels control whether you can perform different operations within the
SEL-421 relay. These security levels are labeled 0, 1, B, P, A, O, and 2.
presents an overview of the general access level structure in the
relay.
Figure 4.5
Access Level Structure.
Access Level 0 is the least secure and most limited access level, and Access
Level 2 is the most secure level at which you have total relay functionality.
For example, from Access Level 1, you can view settings; you cannot change
settings unless you are at a higher access level.
lists access levels
and operator functions for the SEL-421 Relay.
The SEL-421 Relay performs command interpretation and execution
according to your validated access level. Each access level has a password
that the relay must verify before you can control the relay at that level.
lists the access level commands with corresponding
passwords.
Table 4.3
SEL-421 Relay Access Levels
Access Level
Prompt
Allowed Operations
0
=
Log in to Access Level 1; some test diagnostics.
1
=>
View data and status information.
B
==>
Access Level 1 functions plus breaker control and data.
P
P=>
Access Level B functions plus protection settings.
A
A=>
Access Level B functions plus automation settings.
O
O=>
Access Level B functions plus output settings.
2
=>>
Perform all relay access level functions.
Access
Level 0
Access Level x
(Note: Use xAC to switch between any of
the access levels x, where x = B,P,A,O,2)
ACC
QUIT
QUIT
ACC
xAC
Access
Level 1
Summary of Contents for SEL-421
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