Schweitzer Engineering SEL-387-0, Instruction Manual, Page: 141 / 556

4.15
Date Code 20170601 Instruction Manual SEL-387-0, -5, -6 Relay
Control Logic
LED Targeting Logic
LED 7 – 50 –
Instantaneous or
Definite-Time
Overcurrent Trip
This LED will illuminate if any instantaneous or definite-time 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
overcurrent elements indicated by Relay Word bits “50***” or “50***T” and
the Restricted Earth Fault forward direction bit, 32IF.
LED 7
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 8 – 51 – Inverse-
Time Overcurrent
Element Trip
This LED will illuminate if any inverse-time overcurrent element present in
the TR1 through TR5 settings has timed out and is asserted at the rising edge
of the trip or one cycle later. Applicable elements include any of the
overcurrent elements indicated by Relay Word bits “51**(*)T,” which include
the four combined overcurrent elements, as well as the REFP bit indicating
time-out of the Restricted Earth Fault inverse-time curve.
LED 8 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 9 – A – A-Phase
Involved in the Fault
(Programmable LEDA) LED 9
is programmable via the LEDA SEL
OGIC
control equations Global
setting. It is updated each processing interval. If LEDA is true, LED 9 is
illuminated. Otherwise, it is reset. The factory default setting is LEDA = OCA
+ 87E1.
Relay Word bit OCA indicates A-phase overcurrent during the fault. It is
derived by first checking which winding “W
n ” LED is lit, then asserting if the
associated 50A n 4 overcurrent element bit is asserted, or if the magnitude of
the IAW n phase current is greater than or equal to the magnitudes of IBW n
and ICW n .
Relay Word bit 87E1 indicates differential element 87-1 operation and follows
LED 4 operation (see LED 4 – 87-1 – Differential Element 1 on page 4.14 ).
LED 10 – B – B-Phase
Involved in the Fault
(Programmable
LEDB) LED 10
is programmable via the LEDB SEL
OGIC
control equations Global
setting. It is updated each processing interval. If LEDB is true, LED 10 is
illuminated. Otherwise, it is reset. The factory default setting is LEDB = OCB
+ 87E2.
Relay Word bit OCB indicates B-phase overcurrent during the fault. It is
derived by first checking which winding “W
n ” LED is lit, then asserting if the
associated 50B n 4 overcurrent element bit is asserted, or if the magnitude of
the IBW n phase current is greater than or equal to the magnitudes of IAW n
and ICW n .
Relay Word bit 87E2 indicates differential element 87-2 operation and follows
LED 5
operation (see LED 5 – 87-2 – Differential Element 2 on page 4.14 .
LED 11 – C – C-Phase
Involved in the Fault
(Programmable LEDC)
LED 11 is programmable via the LEDC SEL
OGIC
control equations Global
setting. It is updated each processing interval. If LEDC is true,
LED 11
is
illuminated. Otherwise, it is reset. The factory default setting is LEDC = OCC
+ 87E3.
Relay Word bit OCC indicates C-phase overcurrent during the fault. It is
derived by first checking which winding “W
n ” LED is lit, then asserting if the
associated 50C n 4 overcurrent element bit is asserted, or if the magnitude of
the ICW n phase current is greater than or equal to the magnitudes of IAW n
and IBW n .