4.14
SEL-387-0, -5, -6 Relay Instruction Manual Date Code 20170601
Control Logic
LED Targeting Logic
The operation of each LED is discussed in the following paragraphs.
LED 1 – EN –
Relay Enabled
LED 1 illuminates only when the relay is fully enabled and ready for service. It
will turn off if the relay should become disabled by certain critical failure or
alarm conditions. LED 1 is the only green LED of the 16; the remaining LEDs
are red.
LED 2 – TRIP –
Relay Trip
LED 2 illuminates at the rising edge of any of the five trip elements, TRIP1
through TRIP5. It remains lit until reset by the TRGTR element. TRGTR is
asserted for one cycle either via the {TARGET RESET} pushbutton on the front
panel, or via the serial port command TAR R.
LED 3 – INST –
Instantaneous Trip
This LED will illuminate if any instantaneous element present in the TR1
through TR5 settings is asserted at the rising edge of the trip or one cycle later.
Instantaneous elements include any of the overcurrent elements indicated as
“50***,” the Restricted Earth Fault forward direction bit, 32IF, as well as the
87R and 87U differential elements. LED 3 remains lit until reset by the TRGTR
element. TRGTR is asserted for one cycle either via the {TARGET RESET}
pushbutton on the front panel or via the serial port command TAR R.
LED 4 – 87-1 –
Differential Element 1
This LED will illuminate if the differential elements 87R or 87U are present in
the TR1 through TR5 settings, and Relay Word bits 87R1 and 87R, or 87U1,
are found to be asserted at the rising edge of any trip or one cycle later. If so,
the 87E1 bit is also set. LED 4 remains lit until reset by the TRGTR element.
TRGTR is asserted for one cycle either via the {TARGET RESET} pushbutton on
the front panel or via the serial port command TAR R.
LED 5 – 87-2 –
Differential
Element 2
This LED will illuminate if the differential elements 87R or 87U are present in
the TR1 through TR5 settings, and Relay Word bits 87R2 and 87R, or 87U2,
are found to be asserted at the rising edge of any trip or one cycle later. If so,
the 87E2 bit is also set. LED 5 remains lit until reset by the TRGTR element.
TRGTR is asserted for one cycle either via the {TARGET RESET} pushbutton on
the front panel or via the serial port command TAR R.
LED 6 – 87-3 –
Differential Element 3
This LED will illuminate if the differential elements 87R or 87U are present in
the TR1 through TR5 settings, and Relay Word bits 87R3 and 87R, or 87U3,
are found to be asserted at the rising edge of any trip or one cycle later. If so,
the 87E3 bit is also set. LED 6 remains lit until reset by the TRGTR element.
TRGTR is asserted for one cycle either via the {TARGET RESET} pushbutton on
the front panel or via the serial port command TAR R.
12 N
a
Residual element asserted at, or 1 cycle after, rising edge of trip
13 W1
a
Winding 1 overcurrent asserted at, or 1 cycle after, rising edge of trip
14 W2
a
Winding 2 overcurrent asserted at, or 1 cycle after, rising edge of trip
15 W3
a
Winding 3 overcurrent asserted at, or 1 cycle after, rising edge of trip
16 W4
a
Winding 4 overcurrent asserted at, or 1 cycle after, rising edge of trip
a
Indicates nonvolatile targets.
Table 4.6 LED Assignments (Sheet 2 of 2)
LED Legend Description
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