4-14 Control Logic Date Code 20080110
SEL-387E Instruction Manual
LED Legend Description
10 B B-phase involved in the fault (Programmable LEDB)
11 C C-phase involved in the fault (Programmable LEDC)
12 N* Residual element asserted at, or 1 cycle after, rising edge of trip
13 W1* Winding 1 overcurrent asserted at, or 1 cycle after, rising edge of trip
14 W2* Winding 2 overcurrent asserted at, or 1 cycle after, rising edge of trip
15 W3* Winding 3 overcurrent asserted at, or 1 cycle after, rising edge of trip
16 50*/51* O/C element asserted at, or 1 cycle after, rising edge of trip
*Indicates Nonvolatile Targets
The operation of each LED will be 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 four trip elements, TRIP1 through TRIP4. 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 TR4 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 volts/hertz elements 24D1 and 24C2, and the
frequency elements 81Dn (1<
n <6), 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
TR4 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.
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