ABB RELION REX640 Technical Manual page 613

1MRS759142 F
Figure 348: Example of definite time operation of IFPTOC, when Operation principle
= "Touch voltage based", Operating curve type = "Definite time". Setting Touch Vol
Str Val = 40 V and DT stage Op time = 400 ms. Maximum earthing Ris = 10 ohm
When
• Operate time is inverse time according to standard EN50522:
REX640
Technical Manual
Parameter defining maximum earthing resistance, setting
earthing Ris must be always set in case Operation principle = "Touch
voltage based" and
Maximum earthing Ris is needed to scale the estimated earth-
Setting
fault current value into corresponding touch voltage or earth potential
rise value.
Operating curve type = "Inverse time EN50522" is selected, then
Operating curve type = "Definite time" is selected.
Protection functions
Maximum
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