Sel 411L - Page 780

P.12.20
SEL-411L Relay Protection Manual Date Code 20151029
Bay Control
Bay Control Front-Panel Operations
If Relay Word bit 89CCM01 asserts after you press the ENT key, the relay
displays the screen with the caption
CLOSE COMMAND ISSUED in
Figure 12.11 (c) for three seconds. While the disconnect operation is in
progress, the relay displays the screen with the caption
IN PROGRESS in
Figure 12.12 (a) and the disconnect symbol alternately displays the present
state symbol and the opposite state symbol. If another disconnect operation
attempt is made while a disconnect operation is in progress, the relay displays
the screen with the caption
*NOT ALLOWED* in Figure 12.12 (b) for three
seconds and then the relay returns to the screen in Figure 12.12 (a).
If Relay Word bit 89CCM01 does not assert, the relay displays the
*NOT
ALLOWED*
error message shown in Figure 12.11 (d) for three seconds and then
displays again the screen in Figure 12.11 (b).
When Relay Word bit 89CCM01 asserts, the close immobility timer starts. If
Relay Word bit 89CCM01 asserts, two scenarios are possible: the disconnect
fails to close, or the disconnect closes successfully. In the case of a successful
close operation, the relay displays the screen in Figure 12.13 (b).
Failing to close also has two possible scenarios: the disconnect starts to move,
but does not complete the operation, or the disconnect switch operation does
not initiate.
When Relay Word bit 89OPN01 deasserts, the close immobility timer resets,
indicating that the disconnect switch has started to move. If Relay Word bit
89CL01 fails to assert in the expected operation time, the disconnect switch
has failed to complete the close operation in the expected time. Failure of the
89CL01 Relay Word bit to assert in the expected disconnect switch operation
time causes the 89AL1 Relay Word bit to assert. When Relay Word bit 89AL1
asserts, the relay displays the screen Figure 12.13 (a) (see Disconnect Switch
Status and Alarm Logic.)
If Relay Word bit 89OPN01 fails to deassert before the close immobility timer
expires, Relay Word bit 89CIM01 asserts and the relay displays the screen
with the caption
STATUS UNKNOWN in Figure 12.13 (a). See Close and Open
Immobility Timer Logic for more information regarding the close and open
immobility timer logic.
When the disconnect operation completes successfully, the relay displays the
screen in Figure 12.13 (b) until the front-panel timer times out or the ESC
pushbutton is pressed.