Three Phase rotation meter tester, 3 phase rotation multimeter tester and buying considerations

What are phase rotation testers? Phase rotation meters or testers basically tell you if the phasing is either Clock wise or counterclockwise. All testers provide the same function but depending on which type of tester you choose to purchase may make life easier when testing electrical wiring. Below are some of the reasons to purchase each type of phase meter . All phase meters come with Lights to verify power on each leg being supplied and also a lamp showing direction of motor rotation which is always clockwise.

Typical machine problems seen when three phase rotation is not correct or checked.

On the majority of machinery as long as the main incoming power is phased properly, your coolant pumps and the rest of the machine should be phased correctly unless it was altered before. Machines and controls may or may not run properly with the wrong phasing. But when hydraulic pumps, cooler units or coolant pumps are used they will often run backwards and may cause immediate damage to them if not caught within 60 seconds or less. Problems may also occur with the tool magazine, ATC motors, and various brakes used on a machine. Also if the company is using grounded B-phase where one leg has no power essentially this can also cause many intermittent problems so be sure it is phased correctly and that the neutral leg is in the middle or on L2.  Always check all motor rotations on the machine when reapplying the power after a machine is moved and verify the phasing at the incoming before moving the machine to make sure it was correctly hooked up the first time.

The phase meter to the right is great for checking your main incoming power leads. This is because the large 1/2 inch alligator clips make it easy to clamp on to the incoming legs of 3 phase power. There for allowing you to flip on the power going to the main legs ounce the unit is set up to keep your hands free and clear. The meter should not be connected when the power is live due to severe risk of injury especially since most companies use oversize lugs and they are spaced so close together that a mistake can easily be made.

How to check to see if your machine is phased right with a 3 phase rotation meter.

Generally the meter will comes with directions. Basically turn off power and attach the 3 leads in the proper order specified by the manufacturer. Turn on the 3 phase power to the breaker and see what direction is specified on the meter. Generally most motors should be running CCW or counterclockwise. If it is reversed change two leads Typically 1 and 3 lead going to your main breaker on your machine.

Also see motor testing with megohm meter for motor troubleshooting