ABB RELION REX640 Technical Manual page 617

1MRS759142 F
Figure 350: Operation timer characteristic of IFPTOC function when Operation
principle = "Touch voltage based", Operating curve type = "Inverse time EN50522"
and Operating curve type = 1.0. Characteristics are according to standard EN50522.
Maximum earthing Ris = 10 ohm.
Example 5b. Inverse time operation of IFPTOC, when
voltage based",
multiplier = 2.0 is illustrated in
(setting
maximum operate time of 5000 ms (settings
Max Op Tm ). Maximum earthing resistance value encountered in the protected
feeder is set to be 10 ohms (setting
= 1. For illustrating the operating speed requirement of protection, limits of earth
potential rise durations defined in standard EN50522 are shown for reference.
REX640
Technical Manual
Operating curve type = "Inverse time EN50522" and setting UTp
Touch Vol Str Val ). IFPTOC is set to have minimum operate time 100 ms and
Figure 351
. Start value for operation is set to be 40 V
IDMT stage Min Op Tm, IDMT stage
Maximum earthing Ris ) and Reduction factor
Protection functions
Operation principle = "Touch
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