Application; Signals - ABB RELION 620 Series Technical Manual

1MAC504801-IB E
4.1.2.6
4.1.2.7
620 series ANSI
Technical Manual
Operating curve type
(4) Long Time Moderately Inverse
(5) Long Definite Time
(6) Very Long Time Extremely Inverse
(7) Very Long Time Very Inverse
(8) Very Long Time Inverse
(9) Long Time Normal Inverse
(14) IEC Long Time Inverse
(17) Programmable
For a detailed description of timers, refer to section
block features
Table 109: Reset time characteristics supported by different stages
Reset curve type
(1) Immediate
(2) Def time reset
(3) Inverse reset

Application

The long time overcurrent protection is used in special feeder protection application
where operating time provided by 51P is not good enough for coordination purpose.

Signals

Table 110: 51LT Input signals
Name Type
I_A SIGNAL
I_B SIGNAL
I_C SIGNAL
BLOCK BOOLEAN
ENA_MULT BOOLEAN
51LT
x
x
x
x
x
x
x
x
in this manual.
51LT
x
x
x
Default Description
0 Phase A current
0 Phase B current
0 Phase C current
0=False Block signal for activating the blocking mode
0=False Enable signal for current multiplier
Section 4
Protection functions
General function
161