ABB RELION 670 Series Communication Protocol Manual page 64

Section 5
Glossary
58
3I
O
3V
O
Three times zero-sequence current.Often referred to as the
residual or the ground-fault current
Three times the zero sequence voltage. Often referred to as
the residual voltage or the neutral point voltage
1MRK 511 391-UUS C
670 series 2.2 ANSI
Communication protocol manual