Wiring my Powermatic 3520b. It is finally time. Thank Goodness!

[Joshua Dinerstein]

Yeah!!!! It is about freaking time!!!! I bought the lathe almost a year ago. But we are finally in the new house and I can at long last set it up in it's final resting place.

I spent most of Thursday night, Friday night and then this morning working on powering up the new shop. The 50-amp feeder line is in, the panel in the garage is up, the surface mount wires are strung and the gang boxes up. In those boxes I have multiple circuits. A dedicated 20amp for the HF 2hp DC that I have, a dedicated 20amp for the A/C unit that will now be going in since I have power for it, I have the line pulled and strung for my Mustard Monster. I am getting ready to start the setup process on it.

However, I started by reading the manual to find out how to wire it up. I was a bit surprised to find that it only had 3 wires in the pig tail. Having just wired so many 220 breakers and I lines I expected to need all 4 of the wires. The 2 hot (red and black), and the wire and then the green wrapped ground.

I don't have the worlds best understanding of electrical systems but the manual says connect the two hots to the black and white wires and then the green to the green ground.

As I said I am not an expert but I had expected to need the white common wire for the wiring to complete the circuit. Given that so many here have this same fabulous lathe I wanted to ask first.

Given the 4 colors of wires that I have, black and red as hot, white as common/neutral (i have heard it called both), and green as ground. Do I wire it just as the manual says? The 2 hots to what seems to be odd colors and then the ground to the green?

Any one willing to explain what they did and verify things for me so that I can get it set up. Man alive am I excited to turn again. we moved more than a month ago so no turning in all that time. There is an actual physical pain to that... hehehe

Thanks,
Joshua

[Jeff Nicol]

Joshua, Are you hard wiring it to a box without a plug on the end? No matter with 220V single phase you only need three wires, 2 hots and a ground as there is no neutral. When the 220v single PH gets to the VFD it is then changed to 3phase to run the motor. The power from the panel is 115v to each of the hots and the ground keeps you safe! Did you use a 20amp breaker? If so just get a 20amp receptacle and end for the lathe and plug it in and you should be set.

Jeff

[Ken Fitzgerald]

Joshua,

With 220/240 vac...you use two hots for power and then ground the machine for safety. The neutral is not used USUALLY.


Sometimes in special situations you will see a 4 wire 220/240 hookup. Typically that is for something like an oven where you use 220 for the heating elements and 120vac for the clock/timer.



With 110/120 vac ...you use 1 hot and neutral for power and ground the machine for safety.

Follow the manual, Joshua.

[Chris Stolicky]

Like mentioned above, you only need the two hots and ground because the machine is only single phase. So, you basically have an extra wire run. I recently went though this process wiring an outlet for my 1642 (2HP).

I have read, but not yet experienced myself, that some machines will require all three plus the ground. In these cases, the third hot leg would be used for something needing 110v, like a task light.

I'm not an electrician, so I'll throw this out there - could he strip the ends and simply use it as an additional ground wire?

One thing I have learned = ground things as much as possible...

[Cam Livingstone]

Check the motor name plate to be sure it is 220/240 single phase, sends us a pic if you like, 2 grounds sounds like a safety factor but it is not code because it creates a ground loop. White and green only come together at the main breaker box, no where else, not even a sub-panel.

[Maylon Harvey]

Joshua,
Do like has been suggested. But may I also suggest if you are hard wiring it to go through a double pole switch so you can easily turn off the power to the lathe when not in use.

[Ken Fitzgerald]

Cam's correct about not using 2 ground wires.

Will it make a difference with the VS controller? Who knows? I do know with the stuff I work on...we never put two grounds because it can set up ground loop currents that can cause some really serious flaky problems.

My advice would be to hook it up like the manual stipulates. If you are using 4 wire....cut 4th wire back and leave it disconnected..or tie it back so it can't be a problem. In either case, don't use it.

[Joshua Dinerstein]

Thanks all. First off let me say that I was planning to follow the manual. I was just double checking that I didn't get a crappy manual. :) With some things I will leap first and then re-think things. With my baby I just can't bring myself to be quite that cavalier.


\But may I also suggest if you are hard wiring it to go through a double pole switch so you can easily turn off the power to the lathe when not in use.
I was thinking about hard wiring it. It limits movability. But when was the last time I really moved a lathe? Other than the move from 1 house to another that would be... never.

But I did already by a 220v double-pole single throw switch. From what I have been told by the electrician on duty and the manual that came with it I wire it to switch the 2 hots. Given what I read here that continues to sound correct. But now I am wondering about keeping the switch and putting on a plug as well. Given that only 3 wires are in use I can get the connectors I need pretty cheaply at the local borg. Would let me truly move things out of the way if I ever needed too.

But again I wonder when or if that will ever happen. I will have to think about it before Monday when I will start back up on this stuff. Having a big family party tomorrow afternoon here at the new house. I dare say I won't have a minute to breathe tomorrow. I am after all doing the cooking.
Yumm... ribs.

Thanks for the suggestions everybody and the information. I appreciate it.

Joshua

[Ken Fitzgerald]

Joshua,

I prefer the use of a plug. In fact, I unplug mine from the wall whenever I'm not using it.

[Jeff Nicol]

Joushua, The plug in rececptacle is the way to go, you never know when the giant thunderstorm will strike and fry things!

Jeff

[Chris Stolicky]

Yes. What Ken and Jeff said. I wired mine to an outlet and unplug it when not in use.

That's interesting about the 'ground loop'. See, that's why I threw it out there. I figured we have some knowledgeable people around here. Thanks guys.

Not to add to your list :rolleyes:, but something else you might want to consider is adding an additional switch on the end of the lathe. That is, if you didn't already purchase the PM version. I posted some pics of my set up a few weeks ago. I'll find the thread, and come back to edit this thread with a link.

EDIT:
Here's the link- http://www.sawmillcreek.org/showthread.php?t=114646
Note that I wired two switches in a box - one is for the vacuum pump. Some commented about that potentially not being a good idea, and under the right circumstance, I fully agree. I intend on modifying it somehow.

[William Payer]

Joshua,

I am in the "use a plug" camp only because it allows me to totally disconnect all electrical wiring from the controller's electronics. I always have concerns that an electrical surge or spike will come through the line and damage the VFD controller.

[Steve Schlumpf]

Joshua - have fun with your family party! I have the 220v Jet and use the twist-lock style of plug. That way you don't worry about the plug coming out of the wall - through vibration or someone accidentally pulling the cable. Also agree that you should disconnect the plug from power when done turning as the logic circuits on your lathe are always ON. Good habit to get into and is the only way to make sure lightening won't travel through the lines to get to your lathe!

Other thing - I can almost guarantee that if you hard wire your lathe into the power supply - for some unknown reason and at the most inconvenient time - you will have to move the lathe!

Good luck with everything! Looking forward to seeing some turnings off your new lathe real soon!

[Joshua Dinerstein]

Ok. So a plug too. I can still put the switch in I suppose. But if I am going to go with a plug then I suppose I can just bag the switch and return it and go for the typical larger gang box with the round plug in it.

Thanks guys!

Joshua