A Appendix
540
7UT613/63x Manual
C53000-G1176-C160-2
Current Transform-
er in accordance
with
BS 3938/IEC 60044-
1 (2000)
The values of an IEC class P transformer can be converted to the values for an IEC
class PX (BS class X) transformer by using the following formula:
Example: IEC 60044: 600/1, 5P10, 15VA, R
ct
= 4
Ω
IEC PX or BS class X:
Current Transform-
er in accordance
with ANSI/IEEE C
57.13
Class C of this standard defines the CT by its secondary terminal voltage at 20 times
rated current, for which the ratio error shall not exceed 10%. Standard classes are
C100, C200, C400 and C800 for 5A rated secondary current.
The approximate terminal voltage can be derived from the IEC values, as follows:
ANSI transformer definition
U
s.t.max
= 20 • 5A • R
b
• K
ssc
/20
with:
R
b
= P
b
/
I
sn
2
and
I
sn
= 5A
one derives at
U
s.t.max
= P
b
• K
ssc
/5A
Example: IEC 60044: 600/5, 5P20, 25VA
ANSI C57.13:
U
s.t.max
= 25VA • 20/5A = 100V, in accordance with class C100
The calculations listed above are simplified in order to facilitate a quick and safe CT
calculation/verification. An accurate calculation/verification can be carried out with the
Siemens CTDIM program as from V3.21. The results of the CTDIM program have
been released by the device manufacturer.
Relay type
transient
dimensioning factor K
td
minimum required factor
K'
SSC
min. required
kneepoint voltage
7UT613/63x
Transf.
3
BB/line
3
Gen./Motor
5
Содержание SIPROTEC 7UT613 series
Страница 16: ...Contents 16 7UT613 63x Manual C53000 G1176 C160 2 Literature 631 Glossary 623 Index 633 ...
Страница 30: ...1 Introduction 30 7UT613 63x Manual C53000 G1176 C160 2 ...
Страница 506: ...A Appendix 506 7UT613 63x Manual C53000 G1176 C160 2 7UT633 D E ...
Страница 508: ...A Appendix 508 7UT613 63x Manual C53000 G1176 C160 2 7UT633 P Q ...
Страница 510: ...A Appendix 510 7UT613 63x Manual C53000 G1176 C160 2 7UT635 D E ...
Страница 512: ...A Appendix 512 7UT613 63x Manual C53000 G1176 C160 2 7UT635 P Q ...
Страница 515: ...A 2 Terminal Assignments 515 7UT613 63x Manual C53000 G1176 C160 2 7UT633 B ...
Страница 516: ...A Appendix 516 7UT613 63x Manual C53000 G1176 C160 2 7UT633 B Figure A 7 General diagram 7UT633 panel surface mounting ...
Страница 517: ...A 2 Terminal Assignments 517 7UT613 63x Manual C53000 G1176 C160 2 7UT633 N ...
Страница 518: ...A Appendix 518 7UT613 63x Manual C53000 G1176 C160 2 7UT633 N Figure A 8 General diagram 7UT633 panel surface mounting ...
Страница 519: ...A 2 Terminal Assignments 519 7UT613 63x Manual C53000 G1176 C160 2 7UT635 B ...
Страница 520: ...A Appendix 520 7UT613 63x Manual C53000 G1176 C160 2 7UT635 B Figure A 9 General diagram 7UT635 panel surface mounting ...
Страница 521: ...A 2 Terminal Assignments 521 7UT613 63x Manual C53000 G1176 C160 2 7UT635 N ...
Страница 522: ...A Appendix 522 7UT613 63x Manual C53000 G1176 C160 2 7UT635 N Figure A 10 General diagram 7UT635 panel surface mounting ...
Страница 622: ...A Appendix 622 7UT613 63x Manual C53000 G1176 C160 2 ...
Страница 632: ...Literature 632 7UT613 63x Manual C53000 G1176 C160 2 ...