Pm1340gt Lathe Basic Vfd Control Conversion Using The Stock Control Board And Switches

[mksj]

I'm new to working with a lathe, but having to rotate the chuck to find the key most every time I stop seems to be an inefficiency that could be resolved.

Most chucks have either 2 or 3 key chuck pinions, so really not an issue. The chuck rotates easily or bump with the jog. Probably one of the most common requests I get for VFD control systems is for a Joystick Jog, so a very quick way to bump the chuck or turning to a specific spot. A proximity sensor stop used with a VFD will give you pretty much the same exact stopping/chuck position if threading and not disengaging the half nut.
http://www.hobby-machinist.com/thre...ding-with-a-proximity-stop.45977/#post-391715

The Marathon E467 should work very well and give a little better motor control, but the stock PM1340GT 3 phase motor is very good also. That is a very good price on the one your purchased. The E467 (and stock motor) should easily max out at 90Hz maintaining full Hp. Although Torque drops off above the motor's base frequency, the torque at the spindle would be the same as a 60Hz motor when you take into account the mechanical gearing ratio.
Mark

 

[qualitymachinetools]

Great information as always mksj!!!!!!!

 

[chocadile]

I just want to say thank you to Mark for making this information available. I have this exact machine PM-1340GT and WJ200 VFD and after reading trough the manual I feel much more comfortable tackling this project. I will post back and let you know how it's going.

 

[chocadile]

I do have one question for Mark or anyone else who has performed this install. I am up to the point where I am installing the transformer wires onto the terminal block. I wanted to be sure of the orientation of those two wires " S, and R ." In Marks write up he doesn't specify and it's really tough to see the routing of those two in particular. Everything so up to this point has been a breeze. Hopefully the rest of this project will go the same way.

edited to show images of cleaned up board ready to go back onto the machine.

 

[mksj]

There is no orientation to the S and R, since it is 220/240V which is split phase. The wire routing is not critical, I pulled the wires forward and connected them to terminals 1 and 2, so you would need to bring in power 240VAC to the board, You also need to ground the transformer (green terminal) and the control box the same as the stock system.

 

[chocadile]

Thank you for the response Mark. I have left the stock transformer ground as is. Green wire from the green terminal to the side of the transformer on a stud. Do I need to run and additional wire from the green terminal to the ground on the control box?

 

[mksj]

Yes, the control board is phenolic so there is no ground connection from the transformer to the control box. You want to also ground the control box since there is 240VAC coming into it. This assures a good local ground, even though the motor is also grounded. All the grounds should go back to a single point (star ground), such as a metal back plane that the VFD would be mounted to, otherwise you can use a stud mounted where the power comes into the machine.

 

[chocadile]

Mark you've been a great help and it is very much appreciated. I ran the additional ground from the transformer to the control box as you suggested. I think I've run into a problem though.

Like many others this machine sat in the shop for 3 to 4 months before I started this project yesterday. I'm having to deal with existing wiring that I'm not 100% sure is correct. I'm a complete newbie with this and want to be sure things are correct before turning the power back on. Please forgive me if my questions seem very basic.

Here is my problem (I think haha), I'm ready to bring power to the board but it looks like we only have one 208V 3 phase cable coming into the room.

this is the existing wiring I spoke of previously. It looks like the electrician ran the power to the VFD, and them from the VFD to the control board. Here are the connections he made.

From my very limited understanding, this seems incorrect. I believe I need to have two power sources, one for the control board and the other for the VFD. It looks like the area where I need to wire my motor into is being used by the power cord the electrician set up to go to the control board.

This is where I'm at now box and control board mounted to the lathe, and awaiting power to the terminal block.

Please let me know if my assumption is correct/incorrect, and what further steps I need to take.

 

[tmarks11]

Was your machine shipped to you as a 3 phase machine?

Most aren't, most of them operate off of 240V, single phase.

 

[chocadile]

Was your machine shipped to you as a 3 phase machine?

Most aren't, most of them operate off of 240V, single phase.

Yes I believe it was Tim. I'm out of the shop for the night so can't go physically check right now. I am fairly certain it is a 3 phase motor. I'll reaffirm tomorrow.