Phase rotation

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mstrlucky74

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Have existing panels and distribution gear being demolished. Loads are Being temped out and then swung over to new panels gear. If there a chance that there could be an issue with phase rotation of motors or elevators once connected to new panels and gear? How do you prevent this or check and fix it if it's out of phase? Thanks

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Have existing panels and distribution gear being demolished. Loads are Being temped out and then swung over to new panels gear. If there a chance that there could be an issue with phase rotation of motors or elevators once connected to new panels and gear? How do you prevent this or check and fix it if it's out of phase? Thanks

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Check the direction of rotation before you couple the motors up.
 
Use a phase rotation meter on the existing and then make sure that the temp has the same rotation. We use these:

fluke_9040_phase_rotation_tester.jpg
 
We would have checked phase rotation at the controllers and tagged them, BK,RD,BL or whatever before removal.
How does that stop them from going out of phase? What a out motors with disconnects and no controllers?

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What the process in checking phase rotation and changing it if need be? Thanks

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Am I correct in saying you can switch any two phases to reverse the rotation?
Also, do you guys qualify bumping the motor in the presence of a mechanical contractor and potentially having him sign off or is that a bit overkill?
 
Am I correct in saying you can switch any two phases to reverse the rotation?
Also, do you guys qualify bumping the motor in the presence of a mechanical contractor and potentially having him sign off or is that a bit overkill?

Yes, swapping any two conductors will reverse the rotation.
I don't always have a witness when checking rotation but I don't think it is overkill.
 
This is the model I prefer, rugged and no batteries to go bad in the housing.
Instructions PDF on the page.
http://www.tesco-advent.com/knopp-phase-sequence-indicator.html

IMHO it is hard to find a more concrete and positive correlation to lead phase rotation as it affects motor rotation than a motor!
I love it. Also a very unambiguous detection of phase loss via the failure of the motor to rotate. (It does not, however, tell you the details of the phase loss in terms of duplicated, open circuited, shorted, etc.)
 
Read the directions. That is the easiest way. You will need a phase rotation meter and they come with the directions.
Wouldn't you just try the rotation before coupling it to the load? I mean, even if you use a meter to test the phase rotation would you necessarily know how the rotor was previously connected? L1, L2, L3, or L2, L1, L3?
 
For existing installations where you are doing work anywhere in the supply chain, you don't even need a rotation meter, but you must mark all lines that will have any work done to them in a manner that you can assure will get put back the same rotation as they originally were.

Have a disconnect gone bad and needs replaced, mark incoming lines and outgoing lines whether it be phase tape or simply putting I,II,III ink marks on the conductors before disassembling works great. If original install already has a phase ID method going on then it is even simpler, put things back the way they were to begin with.
 
Maybe in the perfect world ABC rotation at the SE means ABC throughout the plant all the way to the motors, but don’t count on it.

Never seen a reversing controller that will also change conductor markings when it reverses, need to develop that idea and patent it:cool:
 
You can buy a rotation meter that will test live and test the motor dead, now you know the motor winding rotation and the old gear rotation.
 
If you are changing something in a service or a feeder that supplies many motors and not touching any branch circuits, and forget to pay attention to phasing before you started work, all you need to do is check the easiest to get to motor for proper rotation when you get things on again. If it is correct they all will be correct. Equipment with a phase monitor installed on it won't run if you end up getting phasing reversed. This leaves you with making sure high leg is in correct position if you happen to have one, but that often is more critical than correct rotation and should be checked before energizing any loads.
 
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