t1Min: Minimum operating time for inverse time characteristics. At high currents
the inverse time characteristic might give a very short operation time. By setting
this parameter the operation time of the step can never be shorter than the setting.
Current
Operate
time
IN1Min
t1Min
IEC15000250-1-en.vsdx
IEC15000250 V1 EN-US
Figure 55: Minimum operate current and operate time for inverse time
characteristics
In order to fully comply with curves definition the setting parameter t1Min shall be
set to the value which is equal to the operate time of the selected IEC inverse curve
for measured current of twenty times the set current pickup value. Note that the
operate time value is dependent on the selected setting value for time multiplier k1.
8.4.3.2 Common settings
M15282-81 v10
tx: Definite time delay for step x. Used if definite time characteristic is chosen.
AngleRCA: Relay characteristic angle given in degree. This angle is defined as
shown in Figure
56. The angle is defined positive when the residual current lags
the reference voltage (Upol = -2U
0
)
Section 8 1MRK 506 375-UEN A
Current protection
172 Railway application RER670 2.2 IEC
Application manual
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