8.3
Date Code 20081022 Instruction Manual SEL-787 Relay
Front-Panel Operations
Human-Machine Interface
Front-Panel
Automatic Messages
The relay displays automatic messages under the conditions described in
Table 8.1.
Front-Panel Security
Front-Panel Access Levels
The SEL-787 front panel typically operates at Access Level 1 and provides
viewing of relay measurements and settings. Some activities, such as editing
settings and controlling output contacts, are restricted to those operators who
know the Access Level 2 passwords.
In the figures that follow, restricted activities are indicated by the padlock
symbol.
Figure 8.2 Access Level Security Padlock Symbol
Before you can perform a front-panel menu activity that is marked with the
padlock symbol, you must enter the correct Access Level 2 passwords. After
you have correctly entered the password, you can perform other Access
Level 2 activities without reentering the password.
Access Level 2 Password Entry
When you try to perform an Access Level 2 activity, the relay determines
whether you have entered the correct Access Level 2 password since the front-
panel inactivity timer expired. If you have not, the relay displays the screen
shown in Figure 8.3 for you to enter the password.
Table 8.1 Front-Panel Automatic Messages
Condition Front-Panel Message
Relay detecting any failure Displays the type of latest failure (see Section 10: Testing
and Troubleshooting).
Relay trip has occurred Displays the type or cause of the trip. Refer to Table 9.1
for a list of trip display messages.
Relay alarm condition has
occurred
Displays the type of alarm. The TRIP LED is also flashing
during an alarm condition.
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