Thermal Overload Protection, One Time Constant Celsius/Fahrenheit Lcpttr/Lfpttr; Identification; Functionality - ABB REC650 Technical Manual

1MRK 511 287-UEN A
6.6
6.6.1
6.6.2
Technical manual
Function
Operate time, non-directional
residual overvoltage
Reset time, non-directional
residual overvoltage
Operate time, directional
residual over current
Reset time, directional
residual over current
Critical impulse time non-
directional residual over
current
Impulse margin time non-
directional residual over
current
Thermal overload protection, one time constant
Celsius/Fahrenheit LCPTTR/LFPTTR

Identification

Function description
Thermal overload protection, one time
constant, Celsius
Thermal overload protection, one time
constant, Fahrenheit

Functionality

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.
The three-phase current measuring protection has an I
time constant and a thermal memory. The temperature is displayed in either in Celsius
or in Fahrenheit depending on whether the function used is Thermal overload
protection one time constant, Celsius LCPTTR or Fahrenheit LFPTTR.
Range or value
45 ms typically at 0.8 to 1.5 x
U
set
85 ms typically at 1.2 to 0.8 x
U
set
140 ms typically at 0.5 to 2 x
I
set
85 ms typically at 2 to 0.5 x I
set
35 ms typically at 0 to 2 x I
set
25 ms typically
IEC 61850
identification
LCPTTR
LFPTTR
Section 6
Current protection
Accuracy
45 ms typically at 0.8 to 1.5 x U
85 ms typically at 1.2 to 0.8 x U
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-
-
-
IEC 60617 ANSI/IEEE C37.2
identification device number
26
26
2
t characteristic with settable
set
set
121