ABB Relion 670 Series Applications Manual page 156

Section 8
Current protection
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
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
tPCrvx, tACrvx, tBCrvx, tCCrvx : Parameters for user programmable of inverse time
characteristic curve. The time characteristic equation is according to equation 41:
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EQUATION1189 V1 EN-US
Further description can be found in the technical reference manual.
tPRCrvx, tTRCrvx, tCRCrvx : Parameters for user programmable of inverse reset time
characteristic curve. Further description can be found in the technical reference manual.
8.4.4.6 Line application example
Four step residual overcurrent protection can be used in different ways. Below is described
one application possibility to be used in meshed and effectively earthed systems.
The protection measures the residual current out on the protected line. The protection
function has a directional function where the polarizing voltage (zero-sequence voltage) is the
polarizing quantity.
The polarizing voltage and current can be internally generated when a three-phase set of
voltage transformers and current transformers are used.
150
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1MRK 511 401-UEN Rev. K
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harmonic restrain function.
Bay control REC670
Application manual
(Equation 41)
M15282-184 v8