Elma Instruments RT 606 (42606) is a three-phase phase sequence and motor rotation direction tester with LED indication, covering 150 to 500 V at 50 to 60 Hz. The instrument is rated IEC 61010-1 CAT III and verifies that the three phases are present and correctly ordered before energising rotating machinery. Typical use is on motor circuits, drives and switchboards during commissioning and service.