ABB Relion 670 series - Thermal overload protection, one time constant LPTTR; Introduction

Function Range or value Accuracy
Residual release current for
all directional modes
(0.25-200.00)% of lBase ± 1.0% of I
n
at I £ I
n
± 1.0% of I at I > I
n
At low setting:
(0.25-1.00)% of I
n
: ±0.05% of I
n
(1.00-5.00)% of I
n
: ±0.1% of I
n
Residual release voltage for
all directional modes
(0.01-200.00)% of VBase ± 0.5% of V
n
at V£V
n
± 0.5% of V at V > V
n
Reset ratio > 95% -
Timers (0.000-60.000) s ± 0.5% ±10 ms
Inverse characteristics, see
table 728, table 729 and
table 730
19 curve types See table 728, table 729 and table
730
Relay characteristic angle
RCA
(-179 to 180) degrees ± 2.0 degrees
Relay open angle ROA (0-90) degrees ± 2.0 degrees
Operate time, non-directional
residual over current
60 ms typically at 0 to 2 x I
set
-
Reset time, non-directional
residual over current
60 ms typically at 2 to 0 x I
set
-
Operate time, pickup function 150 ms typically at 0 to 2 x I
set
-
Reset time, pickup function 50 ms typically at 2 to 0 x I
set
-
7.7 Thermal overload protection, one time constant LPTTR
Function description
IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Thermal overload protection, one time
constant
LPTTR
SYMBOL-A V1 EN
26
7.7.1 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.
1MRK505222-UUS C Section 7
Current protection
449
Technical reference manual