Hitachi Relion 670 Series Applications Manual page 159

1MRK506375-UEN Rev. N
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Figure 60:
The minimum theoretical current setting (Imin) will in this case be:
³
I m in
EQUATION287 V1 EN-US
Where:
I and I
fA fB
Considering the safety margins mentioned previously, the minimum setting (Is) is:
I = 1.3 × I
s
EQUATION288 V3 EN-US
Transformer inrush current shall be considered.
The setting of the protection is set as a percentage of the base current (IBase).
Operation: set the protection to On or Off.
IN>>: Set operate current in % of IB.
8.4 Two step residual overcurrent protection EF2PTOC
8.4.1 Function revision history
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Railway application RER670
Application manual
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A
Fault
I
M
IED
Two parallel lines. Influence from parallel line to the through fault current: I
, ,
M A X I ( I I )
fA fB M
have been described for the single line case.
min
Product History
revision
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© 2017 - 2023 Hitachi Energy. All rights reserved
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Section 8
Current protection
M
(Equation 41)
(Equation 42)
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