Sel 411L - Table 12.4 Three-Position Disconnect Switch State Representations

P.12.24
SEL-411L Relay Protection Manual Date Code 20151029
Bay Control
Bay Control Front-Panel Operations
Table 12.4 displays how the bay screen one-line diagram represents the
different states of the three-position disconnect switch.
y
Similar to the standard disconnect, if a three-position disconnect is
highlighted on the one-line diagram and the ENT pushbutton is pressed, a
control screen is displayed. The control screen shows the present status of the
disconnect based on the disconnect status bits (89CLm, 89OPNm, 89OIPm,
and 89ALm) from both disconnects that make up the three-position
disconnect. The status is shown via the disconnect symbol and the status
labels as shown in Figure 12.15 (a).
Figure 12.15 (a) shows the control screen of a three-position disconnect with
both disconnects in the open state. Figure 12.15 (b) shows the control screen
of a three-position disconnect with the in-line disconnect closed and the
ground disconnect open. Likewise, Figure 12.15 (c) shows the control screen
of a three-position disconnect with the in-line disconnect open and the ground
disconnect closed.
Table 12.4 Three-Position Disconnect Switch State Representations
Apparatus Position Symbol Asserted Relay Word Bits
Both disconnects open 89OPN3 and 89OPN4
Disconnect 3 (in-line) closed
Disconnect 4 (ground) opened
89CL3 and 89OPN4
Disconnect 3 (in-line) opened
Disconnect 4 (ground) closed
89OPN3 and 89CL4
Disconnect 3 (in-line) intermediate
a
Disconnect 4 (ground) opened
b
(89OIP3 or 89AL3) and 89OPN4
Disconnect 3 (in-line) opened
Disconnect 4 (ground) intermediate
a
b
89OPN3 and (89OIP4 or 89AL4)
All other status combinations
Disconnect 3 closed, Disconnect 4 closed
Disconnect 3 closed, Disconnect 4 intermediate
a
Disconnect 3 intermediate
a
, Disconnect 4 closed
Disconnect 3 intermediate
a
, Disconnect 4 intermediate
a
b
89CL3 and 89CL4
89CL3 and (89OIP4 or 89AL4)
(89OIP3 or 89AL3) and 89CL4
(89OIP3 or 89AL3) and (89OIP4 or 89AL4)
a
Intermediate = transition between open and closed states.
b
The image alternates between the two symbols shown.