ABB RELION 670 Series Applications Manual page 147

1MRK 505 337-UUS A
Functions
DRPRDRE function
Communication
SMBRREC function
6.1.5.6 SLCE 8/ASCT characteristics for end-connection
Typical ASCT end-connection is shown in figure 75. For this ASCT connection type, the ampere-
turn balance equation has the form according to equation 15:
×
N 4 I
SUMM
EQUATION1785-ANSI V1 EN-US
The relationships between number of turns for this SLCE 8, ASCT for REB670, is shown in
equation 16, equation
N1 = N2
EQUATION1108 V1 EN-US
×
N3 = 2 N
EQUATION1109 V1 EN-US
N4 k
=
EQUATION1110 V1 EN-US
where:
k
The well-known relationship, between positive, negative and zero sequence current components
and individual phase current quantities is shown in equation 19:
Application manual
= × + × +
N 1 IA N 2 ( IA IB
17 and equation 18:
= N;
× ×
3 N
is a constant, which depends on the type of ASCT
(that is, k=1, for 1/1A ASCT or k=5 for 5/1A ASCT or k=2 for 2/1A ASCT)
Comment
Trip Value Recording feature will be connected to the individual
summated bay current. Therefore recorded trip current values will not
correspond to any actual primary currents. However such records can
still be used to evaluate internal busbar protection, CCRBRF/CCSRBRF
and OC4PTOC/PHS4PTOC protections operation.
All communication features in the IED can be used in the exactly the
same way as with phase segregated design
Autoreclosing function in the IED can be used in the exactly same way as
with phase segregated design.
+ × + +
) N 3 ( IA IB IC )
Section 6
Differential protection
M12141-3 v3
(Equation 15)
(Equation 16)
(Equation 17)
(Equation 18)
141