Date Code 20020129
Front-Panel Interface
8-15
SEL-387E Instruction Manual
Because this is an OFF/MOMENTARY type switch, the MANUAL TRIP 1 switch returns to the
RETURN position after momentarily being in the TRIP position. Technically, the MANUAL
TRIP 1 switch (being an OFF/MOMENTARY type switch) is in the TRIP position for one
processing interval (1/4 cycle; long enough to assert the corresponding local bit LB3 to logical 1)
and then returns to the RETURN position (local bit LB3 deasserts to logical 0 again).
On the display, the MANUAL TRIP 1 switch is shown to be in the TRIP position for two
seconds (long enough to be seen), and then it returns to the RETURN position.
MANUAL TRIP 1
←→
Position: RETURN
Logical 1
LB3
Relay
Word
Bit
RETURN
(logical 0)
MANUAL TRIP
TRIP
The MANUAL CLOSE 1 switch is an OFF/MOMENTARY type switch, like the MANUAL
TRIP 1 switch, and operates similarly.
Local Control State Retained When Relay De-energized
Local bit states are stored in nonvolatile memory, so when power to the relay is turned off, the
local bit states are retained.
For example, suppose the local control switch with local bit output LB1 is configured as an
ON/OFF type switch (see Figure 11.5).
Logical 1
LB1
Relay
Word
Bit
Enable
RECLOSER
Disable
(logical 0)
If power to the relay is turned off and then turned on again, local bit LB1 remains at logical 1.
This is similar to a traditional panel, where enabling/disabling of other functions is accomplished
by panel-mounted switches. If dc control voltage to the panel is lost and then restored again, the
switch positions are still in place. If the switch is in the enable position (switch closed) before
the power outage, it will be in the same position after the outage when power is restored.
Pulse Output Contacts
Use the control button
<CTRL>
to mimic the
PUL
se,
OPE
n, and
CLO
se serial port commands.
This is useful during relay checkout, to verify that output contacts actually function in response
to a command.
Under the
CTRL
menu, use local bit pushbutton functions to select whether to PULSE, CLOSE,
or OPEN individual local bits. The screen will prompt for
“Pulse Close Open.”
Use the
right/left arrow keys and
<SELECT>
to choose.
If
Pulse
is selected, the next screen will prompt for the output to be pulsed. These are
OUT101
to
OUT107
and
ALARM
. Use the up/down arrow keys and
<SELECT>
to choose. The display
will follow with a Yes/No verification request. Again, use the up/down arrow keys and
<SELECT>
to choose.