The phase sequence tester is used to check the direction of phase rotation in the electric machine with three-phase supplies. It provides LED indication of both clockwise and anti-clockwise rotation.
The phase sequence tester finds the continuity, or faulty condition, of all three lines and shows the sequence of phase rotation. It's a fast and effective method to ensure 3-phase outlets and devices are connected correctly.

The DE-721/DE-721B Phase Sequence Tester has a three-phase system measurement ranging from AC 90 V to AC 600 V; also magnetic base allows the instrument to be mounted on a metal panel, which is easy to use.