Schweitzer Engineering Laboratories SEL-421-4 - Page 954

5.22
SEL-400 Series Relays Instruction Manual Date Code 20171006
Control
Bay Control Front-Panel Operations
When you initially enter the Disconnect Control Screen, the disconnect switch is
in one of four states: disconnect open (89OPNm), disconnect closed (89CLm),
disconnect undetermined without alarm (89OIPm), or disconnect undetermined
with alarm (89ALm). If Relay Word bit 89OIPm is asserted, the relay displays the
screen in Figure 5.13(a); if Relay Word bit 89ALm is asserted, the relay displays
the screen in Figure 5.14(a). If both Relay Word bits 89OIPm and 89ALm are
asserted, Relay Word bit 89ALm takes priority. If Relay Word bit 89OPNm is
asserted, the relay displays the screen in Figure 5.12(a). This is the initial screen
for an open-to-close operation. If Relay Word bit 89CLm is asserted, the relay
displays the screen in Figure 5.14(b). This is the initial screen for a close-to-open
operation.
Figure 5.13 HMI Disconnect Operation in Progress
(b) Disconnect Control Screen
After three seconds, return to
the previous screen
BAYNAME
OPEN DISCONNECT
CLOSE DISCONNECT
*NOT ALLOWED*
IN
PROGRESS
DmCTLNM
BAYNAME
OPEN DISCONNECT
CLOSE DISCONNECT
IN
PROGRESS
DmCTLNM
IN PROGRESS
IN PROGRESS
(a) Disconnect Control Screen
89OPN1
asserted
ENTER pressed
with 89OIP asserted