Beckhoff EL34 Series Documentation page 261

Application examples
Fig. 162: EL3453, Power measurement with 3 current transformers on a motor
In the circuit shown above (Fig. EL3453, Power measurement with 3 current transformers on a motor),
ensure that the three-phase system is either earth-free or has an earthed star point. Alternatively a
transformer can be included in a Yy0 circuit.
EL34xx Version: 1.5 261