E-Mon E-PS-A-RTU-N - Manual (Page 21)

Chapter 2 Installation Electrical Installation
PowerSmart+ Advanced Power Quality Meter 21
Figure 2-20 3-Wire 2-Element Open Delta Connection Using 2 PTs, 2 CTs.
Wiring Mode = 3OP2
Figure 2-21 4-Wire Wye 2½-Element Connection Using 2 PTs, 3 CTs.