Sel SEL-421 - Page 192

U.4.62
SEL-421/SEL-421-1 Relay User’s Guide Date Code 20020501
Basic Relay Operations
Operating the Relay Inputs and Outputs
Setting a Control Input for Circuit Breaker Auxiliary Contacts (52A):
ACSELERATOR Software
The procedure in the following steps shows how to program the SEL-421
Relay control input IN101 to read the state of circuit breaker auxiliary
contacts. This example uses a single three-pole tripping breaker. Modify the
procedure listed here for your application.
This example assumes that you have successfully established communication
with the relay; see Making an EIA-232 Serial Port Connection on page 4.6 for
a step-by-step procedure. In addition, you must be familiar with relay access
levels and passwords. See Changing the Default Passwords: Terminal on
page 4.10 to change the default access level passwords. You should also be
familiar with the
ACSELERATOR software. See Section 3: PC Software in the
User’s Guide.
Step 1. Configure the communications port. Start the
ACSELERATOR
software. On the top toolbar, open the Communication menu,
and then click Port Parameters. You will see the Port
Parameters dialog box similar to Figure 4.8. Select the Data
Speed, Data Bits, Parity, and Stop Bits that match the relay
settings. Defaults are 9600, 8, N, 1, respectively. Click OK to
update the
ACSELERATOR software communications
parameters. Confirm that the Communications Status bar at the
bottom of the
ACSELERATOR window says “Connected.”
Step 2. Confirm the correct
ACSELERATOR software passwords.
Reopen the Communication menu and click Port Parameters.
Enter your Access Level 1 password in the Level One
Password text box, and your Access Level 2 password in the
Level Two Password text box. Click the OK button to accept
changes and close the dialog box.
Step 3. Read the present configuration in the SEL-421 Relay. On the
Settings menu, click Read. The relay sends all configuration
and settings data to the
ACSELERATOR software.
Step 4. Access the Global Enable settings. Click on the + mark next to
the Global branch of the Settings tree view. Click on the Global
Settings/Enables branch of the Settings tree view. See
Figure 4.56.
Step 5. Change settings. Set EICIS (Independent Control Input
Settings) to Y by clicking the Y button.