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5.26
SEL-400 Series Relays
Instruction Manual
Date Code 20171006
Control
Bay Control Front-Panel Operations
The following example shows the process of changing a three-position discon-
nect from closed in-line to closed to ground. This process requires that you first
open the in-line disconnect before you can close the ground disconnect.
Starting with the one-line diagram in
, highlight the three-position
disconnect and press the
ENT
pushbutton. If the LOCAL Relay Word bit is
asserted, the control screen shown in
is displayed on the screen.
Note that the only options at this point are to open or close Disconnect SW3.
Therefore, use the
Up Arrow
or
Down Arrow
pushbutton to move the highlight box
to the OPEN SW3 position. Then press the
ENT
pushbutton to open Disconnect
SW3. If Disconnect SW3 successfully opens, the control screen will change as
shown in
Figure 5.16(a)
. Note that the control actions changed so that Discon-
nect SW4 can now be closed. At this point, use the
Up Arrow
or
Down Arrow
push-
button to move the highlight box to the
CLOSE SW4
position and press the
ENT
pushbutton to close Disconnect SW4. If Disconnect SW4 is successfully closed,
the control screen will change as show in
.
Table 5.5
Three-Position Disconnect Switch Control Screen Status and Control Options
State of Disconnects
Status Displayed
Control Options Displayed
Control Actions Available
Disconnect SW3: Open
Disconnect SW4: Open
OPENED
OPENED
SW3
SW4
CLOSE SW3
OPEN
a
CLOSE SW4
CLOSE SW3
NO OPEN CONTROL
CLOSE SW4
Disconnect SW3: Closed
Disconnect SW4: Open
CLOSED
OPENED
SW3
SW4
CLOSE SW3
b
OPEN SW3
CLOSE
CLOSE SW3
OPEN SW3
NO CONTROL for SW4
Disconnect SW3: Open
Disconnect SW4: Closed
OPENED
CLOSED
SW3
SW4
CLOSE
OPEN SW4
CLOSE SW4
c
NO CONTROL for SW3
OPEN SW4
CLOSE SW4
Disconnect SW3: Open
Disconnect SW4: Alarm
OPENED
UNKNOWN
SW3
SW4
CLOSE
OPEN
CLOSE
NO CONTROL for either disconnect
Disconnect SW3: Alarm
Disconnect SW4: Open
UNKNOWN
OPENED
SW3
SW4
CLOSE
OPEN
CLOSE
NO CONTROL for either disconnect
Disconnect SW3: Closed
Disconnect SW4: Alarm
CLOSED
UNKNOWN
SW3
SW4
CLOSE
OPEN
CLOSE
NO CONTROL for either disconnect
Disconnect SW3: Alarm
Disconnect SW4: Closed
UNKNOWN
CLOSED
SW3
SW4
CLOSE
OPEN
CLOSE
NO CONTROL for either disconnect
Disconnect SW3: Closed
Disconnect SW4: Closed
CLOSED
CLOSED
SW3
SW4
CLOSE
OPEN
CLOSE
NO CONTROL for either disconnect
Disconnect SW3: Alarm
Disconnect SW4: Alarm
UNKNOWN
UNKNOWN
SW3
SW4
CLOSE
OPEN
CLOSE
NO CONTROL for either disconnect
a
See
Figure 5.16(a)
.
b
See
Figure 5.16(b)
.
c
See
Figure 5.16(c)
.
Summary of Contents for SEL-421-4
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