FAQ01976 of Power Controllers FAQ

There is no problem if only one G3PX is used but the following issues arise if more than one G3PX is used.
The G3PX-220E[]/240E[](20A/40A) use triac output elements.

If more than one single-phase models is connected to different phases in a three-phase power supply, the power supply distortion or phase control noise may make outputs unstable. (With G3PX-EH/-EHN/-EC Controllers this may cause disconnection/element ON fault detection, overcurrent detection, alarm malfunctions, etc.)

For these reasons, the power supply must be taken from the same phases if using a three-phase power supply.
The G3PX-260(60A)E[] uses a thyristor for the output element and is not easily affected.

G3PX-220E[]/240E[] (20 A/40 A)

Connected to Different Phases

The following countermeasures can be used if it is not possible to take the power from the same phases.
1. Use the G3PX-260E[] (which uses a thyristor as the output element).
2. Use the G3PX-220DU (Three-phase Controller).