Rotation questions


Thread Starter


How can I check and identify the phase rotation (r-y-b) or direction of rotation of load connected motor before connecting the supply?

Well I will probably regret this but I'm going to ASSUME that you are dealing with a 480 Volt three phase circuit. Several Manufactures of
test equipment make a small unit called a phase sequence or motor rotation tester that can be applied to the load side of the starter to
determine proper phase rotation. Some of them even have some type of indicators for normal or reverse rotation.
You may even find a Design Idea in EDN (Cahners Publication) describing this kind of device. It can be easily made with a few resistors, capacitors and LED or Neon lamp.