SEL-451 Data Sheet
Schweitzer Engineering Laboratories, Inc.
12
Advanced Display Points
Create custom screens showing metering values, special
text messages, or a mix of analog and status information
with programmable display points.
shows an
example of how display points can be used to show cir-
cuit breaker information and current metering. As many
as 96 display points can be created. All display points
occupy one, and only one, line on the display at all times.
The height of the line is programmable as either single or
double as shown in
. These screens become
part of the autoscrolling display when the front panel
times out.
Alarm Points
You can display messages on the SEL-451 front-panel
LCD that indicate alarm conditions in the power system.
The relay uses alarm points to place these messages on
the LCD.
shows a sample alarm points screen. The relay
is capable of displaying as many as 66 alarm points. The
relay automatically displays new alarm points while in
manual-scrolling mode and in autoscrolling mode. The
alarm point messages are assigned using SER Points set-
tings. The asterisk next to the alarm point indicates an
active alarm. The inactive alarms can be acknowledged
and cleared using the front-panel navigation buttons.
Auxiliary Trip/Close Pushbuttons and
Indicating LEDs
Optional auxiliary trip and close pushbuttons (see
) and indicating LEDs allow breaker control
independent of the relay. The auxiliary trip/close push-
buttons are electrically separate from the relay, operating
even if the relay is powered down. Make the extra con-
nections at terminals
201
through
208
for a
rear-panel view.
shows one possible set of con-
nections.
The auxiliary trip/close pushbuttons incorporate an arc
suppression circuit for interrupting dc trip or close cur-
rent. To use these pushbuttons with ac trip or close cir-
cuits, disable the arc suppression for either pushbutton by
changing jumpers inside the SEL-451. The operating
voltage ranges of the breaker
CLOSED
and breaker
OPEN
indicating LEDs are also jumper-selectable.
Figure 15
Sample Display Points Screen
Figure 16
Sample Alarm Points Screen
Circuit Breaker 1
--Closed--
DISPLAY POINTS
Circuit BK1 SF6 Gas
--Alarm--
Circuit Breaker 2
A PH= 119.6 A pri
SF6 ALARM
*Unauthorized Access
*Xfmr Fan Fail
*Xfmr Heat Overload
ALARM POINTS
Press to acknldge
Figure 17
Operator Controls (Auxiliary Trip/Close Model)
Figure 18
Optional Breaker Trip/Close Control Switches
and Indicating Lamps
CLOSE
(manual/local)
TRIP
(manual/local)
Remote Close/
Auto-Reclose
Remote Trip/
Protection Trips
BREAKER
OPEN
LED
BREAKER
CLOSED
LED
43
local
To Close
Circuit
43
local
52b
52a
52
TC
–
–
+
+
