Sel 421 - Page 148

U.4.10
SEL-421 Relay User’s Guide Date Code 20090715
Basic Relay Operations
Checking Relay Status
Step 4. To set a new password for Access Level 2, type the following:
PAS 2 nE2Pw- <Enter>
(nE2Pw- becomes the new strong password.)
The relay will return the word
Set and the Access
Level 2 =>> prompt.
Step 5. Set new passwords for each access level.
In a similar manner as the previous step, create new strong
passwords for each access level.
Step 6. Commit these passwords to memory, permanently record your
new passwords, and store this permanent record in a secure
location.
To eliminate password verification for an access level, enter DISABLE in
place of the new password. This action will disable the password of that level;
therefore, the relay does not check for a password upon entering that access
level.
Using DISABLE is not recommended. Always set a unique, strong password
in the relay for each access level. Failure to do this can severely jeopardize the
security of your substation and the power system.
After you enter a new password, the relay pulses the Relay Word bit
SALARM for one second and responds
Set. The relay responds with the
message
Password Disabled if you used the DISABLE parameter.
If you forget a password, or encounter difficulty changing the default
passwords in Changing the Default Passwords: Terminal on page U.4.9, you
can temporarily disable password verification. See Jumpers on page U.2.18
for information on the password disable jumper J18B.
Checking Relay Status
With continual self-testing, the SEL-421 monitors the internal operation of all
circuits to verify optimal performance of relay functions. If an internal circuit,
protection algorithm, or automation algorithm enters an out-of-tolerance
operating range, the relay reports a status warning. In the unlikely event that
an internal failure occurs, the relay reports a status failure. For more
information on relay status, see Relay Self-Tests on page U.6.38.
You can check relay status through a communications port by using a
terminal, terminal emulation computer program, or
ACSELERATOR QuickSet.
In addition, you can use the relay front panel to view status information.
Checking Relay
Status: Terminal
The procedure in the following steps assumes that you have successfully
established communication with the relay (see Making an EIA-232 Serial Port
Connection on page U.4.5). In addition, you must be familiar with relay
access levels and passwords (see Changing the Default Passwords: Terminal
on page U.4.9 to change the default access level passwords).
Step 1. Enter Access Level 1.
a. Using a communications terminal, type ACC <Enter>.
b. Type the Access Level 1 password and press <Enter>.
You will see the Access Level 1 => prompt.
Courtesy of NationalSwitchgear.com