MY brother got his hand on a Leblond regal lathe. It has a 3-phase motor in it and the shop he is putting it in also has 3 phase service. Having never wired a 3-phase lathe before I need to know if the feed wires are dedicated or random? In other words, the three "line in" power wires [red, black, and blue] from the power panel have to be connected to L1, L2 and L3. Is there any specific order? or can they be attached randomly?
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Help with wiring a 3 phase lathe
- Thread starter todd281
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Truly, there is a direction of rotation of the phases.
There is a tool that will show the direction .
Most people just hook them up and bump or short cycle a motor to see direction.
I suggest you use the coolant pump as it won't be hurt by running a backwards rotation but many of the hydraulic pumps can be damaged by running backwards even for a short time.
There is a tool that will show the direction .
Most people just hook them up and bump or short cycle a motor to see direction.
I suggest you use the coolant pump as it won't be hurt by running a backwards rotation but many of the hydraulic pumps can be damaged by running backwards even for a short time.
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- Oct 13, 2014
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As said above, there is no proper sequence and switching any 2 phases will reverse the motor direction. However, some equipment can be damaged by running a motor in reverse, if so you should disconnect the motor mechanically from the machine and determine its rotation before commissioning the machine. Example my Clausing Colchester lathe has a clutch, the installation instructions warn not to run it backwards!
There are also test devices that show 3 phase motor rotation.
There are also test devices that show 3 phase motor rotation.
- Joined
- Nov 14, 2020
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What is a Phase Sequence & Its Significance
The order in which each phase voltages attain its positive peak value is called phase sequence.positive and negative phase sequence & its significance
www.electricalvolt.com
Tester LED Indicator Detector Checker Meter
$17.76
Amazon.com
I like to start out with the standard color code, which is( for 208/240V ):
Black-L1
Red-L2
Blue-L3
White-Neutral, if there is one.
Green( or Green w/Yellow Stripe )-Ground
If the motor turns the wrong direction, switch the Black and Red wires. Technically, you can switch any two of the three, I just prefer to to leave the Blue conductor as L3 at all times. This is especially true if there are phase converters in use. I like to keep the "wild" leg Blue.
This is assuming a simple machine like a mill, lathe, etc that is mean't to run in both directions. As others have pointed out, if it's a device that's mean't to run in one direction, and will be damaged by being reversed; confirm phase rotation with test equipment first.
Black-L1
Red-L2
Blue-L3
White-Neutral, if there is one.
Green( or Green w/Yellow Stripe )-Ground
If the motor turns the wrong direction, switch the Black and Red wires. Technically, you can switch any two of the three, I just prefer to to leave the Blue conductor as L3 at all times. This is especially true if there are phase converters in use. I like to keep the "wild" leg Blue.
This is assuming a simple machine like a mill, lathe, etc that is mean't to run in both directions. As others have pointed out, if it's a device that's mean't to run in one direction, and will be damaged by being reversed; confirm phase rotation with test equipment first.