Siemens siprotec SJ62 User Manual page 625

A Appendix
623
Figure A-85 7SJ64: Voltage connections to two voltage transformers and additionally to any
phase-to-phase voltage (for synchronism check for example) With this type of
connection it is not possible to determine the zero sequence voltage V0. Func-
tions that use the zero sequence voltage must be hidden or disabled.
SIPROTEC 4, 7SJ62/63/64 Handbuch
C53000-G1140-C147-A, Edition 07.2015