ABB RELION RET670 Applications Manual page 517

1MRK 504 163-UUS A
Transformer protection RET670 2.2 ANSI
Application manual
triggered with zone 2 pickup, Z2pick up enumeration has to be selected . If zone 3
select Z3pick up enumeration.
27_COMP: The pickup value of the under voltage seal-in feature can be set using
27_COMP. This is provided in percentage of VBase. Recommended setting is 70%.
timeDelay27: The operate time delay in seconds for the under voltage seal-in. The
recommended time delay is to provide the same trip delay setting as the selected zone
that is, either zone 2 or zone 3.
Section 8
Impedance protection
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