South Bend Wiring for VFD

[Stvnpayton3]

Hey guys I recently bought this south bend and would like to power it up. It has a 1/2 hp 3 phase motor that had the plug removed when I purchased it. The person I bought it from had never powered it up and couldn’t remember how it had been powered before that. I know there’s a lot of info on vfd’s online but I was wondering if anyone could look at the pics of this wiring and tell me about the ground wire they had just kind of placed on there. Most of the wiring I see talks about 3 wires from motor. Basically I’m trying to see if this ground would’ve went to the vfd or to somewhere else. That’s for any info.

 

[Dobermann]

Clearly the green wire is the ground wire although you'd certainly want a more "formal" attachment of it to the machine. The VFD typically will have a dedicated ground terminal along with 3 phase terminals plus whatever power input terminals are required. You'd want to make sure you have a solid ground connection to incoming power, to the machine itself, and the VFD unit whichever one you decide to use. I believe you can use the switch shown there to control the VFD Fwd - Stop - Rev operations but you'd need a separate speed control potentiometer. Some internal rewiring of that switch would be required though.

 

[Stvnpayton3]

Clearly the green wire is the ground wire although you'd certainly want a more "formal" attachment of it to the machine. The VFD typically will have a dedicated ground terminal along with 3 phase terminals plus whatever power input terminals are required. You'd want to make sure you have a solid ground connection to incoming power, to the machine itself, and the VFD unit whichever one you decide to use. I believe you can use the switch shown there to control the VFD Fwd - Stop - Rev operations but you'd need a separate speed control potentiometer. Some internal rewiring of that switch would be required though.

Straight to the point. Thank you

 

[jmm03]

Are you wanting to feed 240 single phase or 120 to your machine? You can mount your choice of VFD almost anywhere but most are designed to be in some form of enclosure. Bring a properly grounded 3 wire cord of at least 14 awg to your VFD. From your VFD run a 4 wire cord to your motor, 3 line conductors and a ground. You can also run them in flex, but depending on where you mount the box sometimes a cord is easier. The switch that is on your machine presently can be used to power forward and reverse but it will not be used to switch the mains, only the low voltage signals that you will get from the appropriate terminals on your VFD. You will need to find the appropriate contacts in the switch, you will need typically 1 common "hot" and 1 each switched normally open contacts, the manual with your VFD will give you several choices of operation depending on how you want to control your machine. If your VFD has a remote operator panel you can buy a cord to mount it where you can see the display for speed reference and control, you can control the lathe from the remote panel but it is usually better to wire separate control switches for durability. You usually can use the remote as a display without too much problem, along with the control potentiometer if it has one. If it doesn't have a pot you will need to get one of the appropriate resistance and mount it conveniently in its own box, if you buy from a source like Factorymation or Automation direct, most times you will be able to get choices of components that will work with your application and assistance if you need help. I would recommend that you stay away from the cheapo chinese units . Sorry for the long winded response, take pictures of your installation once you are done please and ask as many questions as you need to, most people on these boards are pretty helpful. Jim

 

[rons]

From reading your description I assume the electrical box is at the motor.
A green ground wire is assumed to be ground. Just avoid any ground loops especially with VFDs.
You can look it up.

 

[Stvnpayton3]

Are you wanting to feed 240 single phase or 120 to your machine? You can mount your choice of VFD almost anywhere but most are designed to be in some form of enclosure. Bring a properly grounded 3 wire cord of at least 14 awg to your VFD. From your VFD run a 4 wire cord to your motor, 3 line conductors and a ground. You can also run them in flex, but depending on where you mount the box sometimes a cord is easier. The switch that is on your machine presently can be used to power forward and reverse but it will not be used to switch the mains, only the low voltage signals that you will get from the appropriate terminals on your VFD. You will need to find the appropriate contacts in the switch, you will need typically 1 common "hot" and 1 each switched normally open contacts, the manual with your VFD will give you several choices of operation depending on how you want to control your machine. If your VFD has a remote operator panel you can buy a cord to mount it where you can see the display for speed reference and control, you can control the lathe from the remote panel but it is usually better to wire separate control switches for durability. You usually can use the remote as a display without too much problem, along with the control potentiometer if it has one. If it doesn't have a pot you will need to get one of the appropriate resistance and mount it conveniently in its own box, if you buy from a source like Factorymation or Automation direct, most times you will be able to get choices of components that will work with your application and assistance if you need help. I would recommend that you stay away from the cheapo chinese units . Sorry for the long winded response, take pictures of your installation once you are done please and ask as many questions as you need to, most people on these boards are pretty helpful. Jim

I appreciate your response. I will call factorymation or automation to get exactly what I need. Thank you

 

[rons]

A VFD will require a direct-to-motor connection. No electrical controls in front.