Schweitzer Engineering SEL-387-0, Instruction Manual

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4.16
SEL-387-0, -5, -6 Relay Instruction Manual Date Code 20170601
Control Logic
Trip and Close Logic
Relay Word bit 87E3 indicates differential element 87-3 operation and follows
LED 6
operation (see LED 6 – 87-3 – Differential Element 3 on page 4.14 ).
LED 12 – N – Residual
Overcurrent Element
Trip
This LED will illuminate if any residual overcurrent element present in the
TR1 through TR5 settings is asserted at the rising edge of the trip or one cycle
later. Applicable elements include any of the winding overcurrent elements
indicated by Relay Word bits “50N**,” “50N**T,” or “51N*T.” Also included
are Combined Overcurrent elements indicated by Relay Word bits 51NC1T
and 51NC2T and the Restricted Earth Fault bits, 32IF and REFP.
LED 12
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 13 – W1 –
Winding 1 Overcurrent
Element Operation
This LED will illuminate if any Winding 1 overcurrent element present in the
TR1 through TR5 settings is asserted at the rising edge of the trip or one cycle
later. Applicable elements include any of the 23 Relay Word bits associated
with Winding 1 overcurrent elements.
LED 13 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 14 – W2 –
Winding 2
Overcurrent Element
Operation
This LED will illuminate if any Winding 2 overcurrent element present in the
TR1 through TR5 settings is asserted at the rising edge of the trip or one cycle
later. Applicable elements include any of the 23 Relay Word bits associated
with Winding 2 overcurrent elements.
LED 14 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 15 – W3 –
Winding 3
Overcurrent Element
Operation
This LED will illuminate if any Winding 3 overcurrent element present in the
TR1 through TR5 settings is asserted at the rising edge of the trip or one cycle
later. Applicable elements include any of the 23 Relay Word bits associated
with Winding 3 overcurrent elements.
LED 15 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 16 – W4 –
Winding 4
Overcurrent Element
Operation
This LED will illuminate if any Winding 4 overcurrent element present in the
TR1 through TR5 settings is asserted at the rising edge of the trip or one cycle
later. Applicable elements include any of the 23 Relay Word bits associated
with Winding 4 overcurrent elements.
LED 16 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 .
Trip and Close Logic
The trip logic and close logic for the SEL-387 operate in a similar manner.
Each has a SEL
OGIC
control equation setting to set or latch the logic and
another SEL
OGIC
control equation setting to reset or unlatch the logic. Each
also has other elements or functions that will unlatch the logic. The output of
each logic is a Relay Word bit that can be assigned to operate output contacts
or in any other manner for which a Relay Word bit can be used. The specifics
of each type of logic are discussed below.