ABB RELION REX640 Technical Manual page 611

1MRS759142 F
Figure 347: Operation timer characteristic of IFPTOC-function when Operation
principle = "EF-current based" and Operating curve type = "Inverse time IEEE80".
Setting IEEE multiplier is 500,Maximum earthing Ris is 10 ohms, EF current Str Val =
0.02*In (2 A), IDMT stage Min Op Tm = 100 ms and IDMT stage Max Op Tm = 5000
ms. Reduction factor = 1.0. Characteristics are according to standard IEEE80.
Principle based on touch voltage estimate
The operation of IFPTOC based on touch voltage estimate is described next. In
case
the estimated touch voltage magnitude according to
content of touch voltage can be included into estimate with setting
harmonics = "Enable".
REX640
Technical Manual
Operation principle = "Touch voltage based", then operation is based on
Protection functions
Equation 119
. The harmonic
Enable
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