Hitachi Relion 670 Series Applications Manual page 130

Section 8
Current protection
INx>Max and INx>Min should only be changed if remote setting of operation current level, INx>, is used.
The limits are used for decreasing the used range of the INx> setting. If INx> is set outside INx>Max and
INx>Min, the closest of the limits to INx> is used by the function. If INx>Max is smaller than INx>Min, the
limits are swapped.
kx: Time multiplier for the dependent (inverse) characteristic for step x.
IMinx: Minimum pickup current for step x in % of IB. Set IMinx below Pickupx for every step to achieve
ANSI reset characteristic according to standard. If IMinx is set above for any step, signal will reset at
current equals to zero.
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.
Trip time
tx
txMin
ANSI10000058 V1 EN-US
Figure 60:
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 (MULTPUx) 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: To enable freezing of timers of step x from 2
tPCrvx, tACrvx, tBCrvx, tCCrvx: Parameters for user programmable of inverse time characteristic curve.
The time characteristic equation is according to equation 41:
124
Minimum pickup current and trip time for inverse time characteristics
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Pickup current
ANSI10000058-1-en.vsdx
nd
harmonic restrain function.
Phasor measurement unit RES670
1MRK511407-UUS Rev. N
Application manual