ABB Relion 670 Series Technical Reference Manual page 455

1MRK505222-UUS C
7.7
7.7.1
Technical reference manual
Function
Residual release current for
all directional modes
Residual release voltage for
all directional modes
Reset ratio
Timers
Inverse characteristics, see
table 728, table 729 and
table 730
Relay characteristic angle
RCA
Relay open angle ROA
Operate time, non-directional
residual over current
Reset time, non-directional
residual over current
Operate time, pickup function
Reset time, pickup function
Thermal overload protection, one time constant LPTTR
Function description
Thermal overload protection, one time
constant
Introduction
The increasing utilizing of the power system closer to the thermal limits has generated
a need of a thermal overload protection also for power lines.
A thermal overload will often not be detected by other protection functions and the
introduction of the thermal overload protection can allow the protected circuit to
operate closer to the thermal limits.
Range or value
lBase
(0.25-200.00)% of
VBase
(0.01-200.00)% of
> 95%
(0.000-60.000) s
19 curve types
(-179 to 180) degrees
(0-90) degrees
60 ms typically at 0 to 2 x I
set
60 ms typically at 2 to 0 x I
set
150 ms typically at 0 to 2 x I
set
50 ms typically at 2 to 0 x I
set
IEC 61850
identification
LPTTR
Section 7
Current protection
Accuracy
± 1.0% of I at I £ I
n n
± 1.0% of I at I > I
n
At low setting:
(0.25-1.00)% of I : ±0.05% of I
n
(1.00-5.00)% of I : ±0.1% of I
n
± 0.5% of V at V£V
n n
± 0.5% of V at V > V
n
-
± 0.5% ±10 ms
See table 728, table 729
730
± 2.0 degrees
± 2.0 degrees
-
-
-
-
IEC 60617 ANSI/IEEE C37.2
identification device number
26
SYMBOL-A V1 EN
n
n
and table
449