Ct Grounding - ABB RELION REB500 Applications Manual

Section 5
System functions
IEC18000758 V3 EN-US
Figure 21:
5.3

CT grounding

The location at which the CT neutrals are grounded (line or busbar side) is of consequence to
directional protection functions (Distance protection DIST, Directional overcurrent definite
time protection DIROCDT and Directional overcurrent inverse time protection DIROCINV).
The following table lists the functions with provision for configuring the location of the CT
neutral ground:
Table 12:
Protection function
Distance protection
Directional overcurrent definite time
protection
Directional overcurrent inverse time
protection
The default setting for the last two functions is busbar side, but if a Distance protection
function has been configured, its setting (line or busbar side) applies for the directional
overcurrent functions as well.
28
Licensed BP function groups
CT grounding setting
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17000038-IEC18000758-3-en.vsdx
Provision for configuring the CT ground?
yes
no
no
1MRK 505 403-UEN Rev. C
GUID-B7027FAC-814A-4F71-A9F0-9F1BC8F78A33 v1
Bay protection functions REB500
Application manual