ABB RED650, Applications Manual

Page: 180 / 454

txMin : 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.
IMinx
Operate time
Current
tx
txMin
IEC10000058
IEC10000058 V2 EN-US
Figure 83: Minimum operate current and operate time for inverse time
characteristics
In order to fully comply with the curves definition, the setting parameter txMin
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
kx .
INxMult : Multiplier for scaling of the current setting value. If a binary input signal
(ENMULTx) is activated, the current operation level is increased by this setting
constant.
ResetTypeCrvx : The reset of the delay timer can be made in different ways. The
possibilities are described in the technical reference manual.
tResetx : Constant reset time delay in s for step x.
HarmBlockx : This is used to enable block of step x from 2
nd
harmonic restrain
function.
tPCrvx, tACrvx, tBCrvx, tCCrvx : Parameters for user programmable of inverse
time characteristic curve. The time characteristic equation is according to
equation
112 :
Section 8
1MRK 505 393-UEN B
Current protection
174 Line differential protection RED650 2.2 IEC
Application manual