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Discussion Starter · #1 ·
Not sure how to phrase the question but here goes,
I was wondering if there was a standard for marking the phases in respect to rotational direction. Like would the wires mared with red tape allways be 120degrees ahead of the wires with blue tape(or vice Versa)? The reason I ask is I was wondering if I would be able to assume that if I took a 3 phase motor and marked wich lines were connected to Red and Blue and hooked it back up in another location with same wires connected to red and blue would it rotate the same way? Or are red and blue just to keep track of things on any one given site and are not indicitive of directional rotation?
Thanks Jim
 

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Fentoozler
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In a perfect world, the coding with correspond with both phase and rotation.
Since the world is not perfect, we accept the color and phase and "guess" at rotation...most times:
- "A" [black] phase will correspond with L1
- "B" [red] phase will correspond with L2
- "C" [blue] phase will correspond with L3

....when it doesn't, we bust out with the rotation meter:
 

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http://www.3phasepower.org/3phasewiring.htm

^^ Not sure if that helps.

I wouldn't ever trust color coding...ever. After the services were switched at my shop I went to open the garage door to put my truck in and "CRUNCH GRRRRR". Think a three phase garage door opener can bend a garage door? You bet!
 

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Discussion Starter · #4 ·
Thanks Celtic
So what I have learned is that my best chance of haveing the motor rotate the correct way when I test it is to match the lines to the colors they were hooked to a the original location.

Inner10
I would still always test but maybe, just maybe this will change the 50-50-90 rule to at least 50-50 that it will be correct the first time. Lucky for me I can bump test the machine and then swap phases. Wont need to buy the rotation meter.

Cheers Jim
 

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http://www.3phasepower.org/3phasewiring.htm

^^ Not sure if that helps.

I wouldn't ever trust color coding...ever. After the services were switched at my shop I went to open the garage door to put my truck in and "CRUNCH GRRRRR". Think a three phase garage door opener can bend a garage door? You bet!
You are right- but Celtic's Posts says to, when in Doubt, bring out the Phase Rotation Tester.
In Industry Most Cables aren't color coded, all black,but labeled 1,2 &3. Lots of times you couldn't even find that. We bumped tested everthing, even after using a Phase Rotation meter.

When unhooking cables we always put one wrap of tape around Phase 1, & 2 wraps of tape around phase 2, & nothing on 3 to Indentify them
 

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Fentoozler
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Thanks Celtic
So what I have learned is that my best chance of haveing the motor rotate the correct way when I test it is to match the lines to the colors they were hooked to a the original location.
Yup.
That is the best option when replacing a motor [and no rotation meter is handy]...but it may still run in reverse.....bumping the motor to visualy verify rotation may be necessary.
 

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Service & Repairs
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In a perfect world, the coding with correspond with both phase and rotation.
Since the world is not perfect, we accept the color and phase and "guess" at rotation...most times:
- "A" [black] phase will correspond with L1
- "B" [red] phase will correspond with L2
- "C" [blue] phase will correspond with L3

....when it doesn't, we bust out with the rotation meter:

How much do one of them things cost? I don't do much motor work but when I do it will save the "hey is it working right now" routine I go through whenever moving/ relocating triple-phase motors.
 

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ampman
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How much do one of them things cost? I don't do much motor work but when I do it will save the "hey is it working right now" routine I go through whenever moving/ relocating triple-phase motors.
mine is a amprobe but when you need one they are invaluable
 

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ampman
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How much do one of them things cost? I don't do much motor work but when I do it will save the "hey is it working right now" routine I go through whenever moving/ relocating triple-phase motors.
triple phase motors --what
 

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Yea, but do you call it one-phase?


No, you call it single-phase. Ergo, 3-phase would be triple-phase.
 
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Fentoozler
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Yea, but do you call it one-phase?


No, you call it single-phase. Ergo, 3-phase would be triple-phase.

My personal fav is 2 phase....or is it ....dual phase...double phase....bi-phase??? :thumbup:

:laughing:
 

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I own stock in FotoMat!
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If you're going to spend the money on a rotation meter, get one that will give you the rotation of both the motor and the power supply. That way, you can be 100% sure the rotation will be correct before you ever energize the motor.

Some equipment doesn't take too well to running backwards, even if you just 'bump' the motor.
 

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Service & Repairs
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Yea, but do you call it one-phase?


No, you call it single-phase. Ergo, 3-phase would be triple-phase.
That's exactly right. I used to work with a kid who used to call it "triple-phase" so I kind of throw that out there from time to time.

Single phase/ triple phase... :laughing:
 

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If you're going to spend the money on a rotation meter, get one that will give you the rotation of both the motor and the power supply. That way, you can be 100% sure the rotation will be correct before you ever energize the motor.

Some equipment doesn't take too well to running backwards, even if you just 'bump' the motor.
The last set of motors I worked on I had to relocate (4) 10HP 208/ 230V motors from one shop to another. The system was a 4-wire delta and each of the motors was wired correctly the first time, phase wise that is. Must be the luck of the Irish. ;)
 

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ampman
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If you're going to spend the money on a rotation meter, get one that will give you the rotation of both the motor and the power supply. That way, you can be 100% sure the rotation will be correct before you ever energize the motor.

Some equipment doesn't take too well to running backwards, even if you just 'bump' the motor.
very true i have wiried up several 60-hp well motors for groves and greenhouses and they don't like to be bumped backwards
 
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