Siemens SIPROTEC 7UT613 series Manual page 67

7UT613/63x Manual
C53000-G1176-C160-2
For side 2, the same considerations apply as for the side 1: The primary rated voltage
UN-PRI SIDE 2 (under address 321), the starpoint condition STARPNT SIDE 2
(under address 323). Observe strictly the assignment of the side according to the to-
pological definitions made before.
The primary rated apparent power under address 322 SN SIDE 2 is that of the
winding assigned to side 2. Concerning power transformers with more than two wind-
ings, the windings may have different power ratings. The power must always be
entered as a primary value, even if the device is generally configured in secondary
values. The device calculates the rated current of the protected winding from this
power.
The mode of connection CONNECTION S2 (address 324) and the vector group
numeral VECTOR GRP S2 (address 325) must match the transformer data of the
transformer windings at side 2. The vector group numeral states the phase displace-
ment of side 2 against the reference winding, side 1. It is defined according to IEC as
the multiple of 30°. If the higher voltage side is the reference (side 1), you may take
the data directly from the vector group designation. For instance, for a transformer Yd5
is CONNECTION S2 = D and VECTOR GRP S2 = 5. Every vector group from 0 to 11
can be set provided it is possible (for instance, Yy, Dd and Dz allow only even, Yd, Yz
and Dy allow only odd numerals). For the auto-connected winding of auto-transform-
ers and for single-phase transformers, only Y 0 is permissible.
If a reference winding other than the higher voltage one is used, it must be noted that
this changes the vector group numeral: e.g. a Yd5 transformer is regarded from the
lower voltage side as Dy7.
Figure 2-11 Change of the transformer vector group if the lower voltage side is the reference
side — example
If the power transformer includes more than 2 windings or assigned sides, similar con-
siderations apply for the further windings (winding 4 and 5 only with 7UT635). If you
have declared the starpoint connections of an auto-transformer bank as a separate
side in order to establish a current comparison protection for each of the windings
(refer also to Figure 2-7 and the respective notes under „Auto-Transformer Banks"),
no settings will be presented for this side as they would have no meaning for this ap-
plication. If in an auto-transformer side S3 or S4 is a compensation winding, the mode
of connection is always assumed to be „D", and only odd-numbered vector groups can
be selected for these sides.
2.1 General
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