Results 1 to 8 of 8

Thread: Wiring up Powermatic 3520C - How to...

  1. #1

    Wiring up Powermatic 3520C - How to...

    I received my 3520C, and am one of the lucky persons to not receive a power cable. The wiring diagram in the back of the manual is lackluster, and, to paraphrase the portion of the manual that talks about wiring the machine:::: "Don't screw it up. Have it worked on by an electrician.". I did some searching and couldn't find any direct help on the interwebs, so I decided that I would create a thread to help anyone else that was looking for help.

    To set the stage, this machine requires 220V Single Phase power. This comes from grabbing 110V from 2 wires, and feeding them both into the machine.

    I was in a situation where I had a breakout box with 4-wire 220V right next to where I wanted to put my lathe. There was no receptacle in the box, so I had the freedom to start with something new.

    Ultimately, I purchased the following:
    NEMA L620R receptacle (basically - a 3 prong plug that has a slight twist lock function). This plug is rated for 20 amps at 220V.
    black-eaton-electrical-outlets-receptacles-l620r-64_1000.jpg

    NEMA L620P cord plug (matches the receptacle)

    8' of 12-3 SJO cable (this is a flexible cable that has 3 insulated wires inside; a black, white and green).

    Installation specific - I bought these as well
    1" extension spacer for the 4" box (also called a 1900 box)
    a plug plate for the 4" box

    I started on the cable. This was pretty easy. The inside of the cable was labeled X, Y and G. Since both the White and Black wires of the 12-3 SJO cable will be "hot" (220v - 110v from each wire), it really doesn't matter. That said, Black is usually the X, and White (in this case - but Y is actually Red - more on that later) is hot, and will attach to Y. Green is ALWAYS ground - or at least you should always think of it that way. So - inside my plug from the 12-3 SJO cable:: Black to X, White to Y and Green to G.

    Now to the other end of the cable - to the lathe. Inside the lathe power switch, there is some sharpie that says B-2, W-4..... Taking a look, you see that there are 2 other inputs on the switch itself.

    2018-06-28 20.02.02.jpg

    I first removed the rubber grommet inside the compression fitting that allows the cable to come into the box (the 12-3 wouldn't fit). I next removed the ground wire from the bar across the top, and just hard wired the Green wire to the "bus bar" - or "ground bar". Now, strip the ends of the White and Black and insert Black into the #1 hole, and White into the #3 hole. Tightly screw these in and push the cover back onto the box and screw it in.

    Your lathe now has a power cable!

    Next - onto the receptacle....

    As I mentioned, my 220v box was run using 4 wires. Black, Red, White and a bare copper wire (Green). In this case, the White and the bare copper (Green) serve the same purpose. Your wires my be different - and if you're not sure, please talk to an electrician. Here's a pic of my shop panel.

    2018-06-29 09.25.17.jpg

    The 220V wire is fed through the bottom, to the breaker on the right side. You can see the Black and Red are wired into the breaker - these are the "hot" wires (or 110V each Black and Red == 220V). The White goes to a bus bar, as does the Ground.

    To wire the receptacle, you simply need to wire up the Black, Red and bare copper to the plug. The white screws on a plug indicate electricity. Mine were labeled X, Y and G. I wired the plug up and put a wire nut on the "White" wire coming from the electrical panel. Basically the White wire is rolled up inside the box, and isn't connected to anything.

    Screw it all in. Plug it in and try it out.

    Worked for me.

    2018-06-29 16.34.25.jpg

    Of note - I have been told that all electronics come pre-filled with an appropriate amount of smoke built in. Under no circumstances do you want to release this smoke....... So - be careful. And know - just because you are excellent at woodworking, doesn't mean you have to be good at wiring stuff up. If you're not sure, do ask an expert.

  2. #2
    Join Date
    Feb 2007
    Location
    Inver Grove Heights, MN
    Posts
    634
    Since you are using the white wire in your cable as one side of your 220V service you should mark it as such. ink, paint, red, or black electrician tape are all acceptable for marking. You don't want someone in the future looking at it and assuming that there is 110V between the white and black wires.

  3. #3
    Quote Originally Posted by Paul Williams View Post
    Since you are using the white wire in your cable as one side of your 220V service you should mark it as such. ink, paint, red, or black electrician tape are all acceptable for marking. You don't want someone in the future looking at it and assuming that there is 110V between the white and black wires.
    That's a good point. The one thing to remember though is that the plug on the other end is a 220V plug, and won't go into a 110V outlet (assuming you're talking about the power cord for the lathe).

  4. #4
    Join Date
    Aug 2016
    Location
    Spokane, WA
    Posts
    225
    Quote Originally Posted by Jeff Steiner View Post
    I received my 3520C, and am one of the lucky persons to not receive a power cable.
    It is my understanding that the 3520c doesn't ship with a power cord, at least I was told this by the Powermatic reps a couple weeks ago.

    Thank you for your write up, very well written.

  5. #5
    When I called PM support they said about 1/2 of them are shipping with cords. However, even if you received a power cord, it doesn't have a plug on it (and - it's not connected to the machine). Interestingly, the tech rep told me they were shipped with 8' of 14-3, which surprised me. I wouldn't think that 14-3 would be thick enough for the tool - but I'm not an electrician...

  6. #6
    Join Date
    Sep 2015
    Location
    San Diego, Ca
    Posts
    1,033
    Jeff, in general, 14 gauge is good for 15 amps. 12 gauge is good for 20 amps.

  7. #7
    Join Date
    Apr 2018
    Location
    Cambridge Vermont
    Posts
    205
    Power cords are rated differently that the wiring in your house. The engineers who designed the lathe can base their choice of wire gauge based on is use. For example it's unlikely that the motor will be drawing the maximum current all the time the lathe is in use. They also can calculate what the allowable voltage drop would be for the lathe. The electrical code for wiring has no way of knowing what will be plugged into an outlet so they assume worse case.

  8. #8
    I had no idea - thank you for the descriptive info. Makes much clearer sense now.
    Quote Originally Posted by Alex Zeller View Post
    Power cords are rated differently that the wiring in your house. The engineers who designed the lathe can base their choice of wire gauge based on is use. For example it's unlikely that the motor will be drawing the maximum current all the time the lathe is in use. They also can calculate what the allowable voltage drop would be for the lathe. The electrical code for wiring has no way of knowing what will be plugged into an outlet so they assume worse case.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •