HD-3A energy-saving limit three-phase power supply protector

The current transformer H11-3 needs to be homemade. You can choose a core of a transformer no smaller than 2W and wind the secondary first. Use Φ0.12mm enameled wire to wind 1000 turns. For the primary stage, use Φ1~4mm plastic wire to wind 2-3 turns. Finished current transformers can also be used. The induced voltage of the finished current transformer is relatively high.