Power Controller Topic: Use 3-phase Power Supply for Single-phase Power Controller

FAQ No. FAQ01976

Question

Is it possible to use a three-phase power supply for single-phase G3PX Power Controllers?

Answer

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 Connected to the Same Phases

Diagram: Connect to different phases (left), Connect to the same phases (right)

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).

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