MIG Welder Table - To Ground or Not to Ground?
Page 1 of 3 1 2 3 LastLast
Results 1 to 10 of 25
Like Tree55Likes

Thread: MIG Welder Table - To Ground or Not to Ground?

  1. Top | #1
    RetiredDoc's Avatar
    Join Date
    Apr 2016
    Last Online
    06-13-2019 @ 06:24 PM
    Location
    Central Savannah River Area (CSRA)
    Posts
    913
    Thanks
    162
    Thanked 144 Times in 110 Posts

    MIG Welder Table - To Ground or Not to Ground?

    Rookie welder here, with a Millermatic 211. I just bought a Miller welding table, and the brief instructions with it say "if you wish to ground the table...".

    I spent yesterday evening googling the subject, and there are a lot of strong opinions out there, on both sides.

    I plan to use the welder with two power sources, depending on whether the work can be moved into my shop to the table or not. In the shop, there is a dedicated welder outlet with its own 240V electrical circuit from the barn sub-panel. The second power source for outside is a Honda portable generator, which is floating ground.

    My question really related to the table, but if there are any recommendations about the generator I'd appreciate those as well.

    Thanks.
    Robnik likes this.
    1025R, H120 FEL, 60D MMM, Rhinohide canopy, iMatch, Frontier BB2060L, SS1067, RC2048, Heavy Hitch front weight carrier, subsoiler, trash bin carrier, rear hitch plate, Titan ballast box, 42 inch forks, Tarter chain harrow, Yard Tuff arena drag, DragnFly Arena Groomer, Newer Model 225 manure spreader, Ken's bucket hooks, Piranha tooth bar, Fimco 40 gallon 3pt boom sprayer,

  2. Remove Advertisements
    GreenTractorTalk.com
    Advertisements
     

  3. Top | #2

    Join Date
    Jul 2015
    Last Online
    Yesterday @ 10:33 PM
    Location
    Near Roa. VA
    Posts
    3,579
    Thanks
    43
    Thanked 437 Times in 337 Posts
    I ground my table, but, I do not care if an arc occurs on the surface,

    The best approach would be to ground the table, then have an auxiliary ground wire/clamp from the table to the part being welded.
    glc, flyweight and Robnik like this.
    Some of the tractors include JD 4105, JD 855, JD 650,,,, and,,, the IH 584 4WD
    My favorite attachment is the homemade landplane,,, EVERYONE needs one of those!!

  4. The Following User Says Thank You to CADplans For This Useful Post:

    RetiredDoc (03-25-2018)

  5. Top | #3
    Captain Hook Kennyd's Avatar
    Join Date
    Aug 2010
    Last Online
    Today @ 07:34 AM
    Location
    Westminster, MD
    Posts
    16,240
    Thanks
    4,992
    Thanked 4,030 Times in 2,510 Posts
    Just to be clear, are we talking about an "earth" ground or the ground lead from the welder?
    mjncad, glc, Ray_PA and 2 others like this.
    Kenny

    -John Deere 3720 Deluxe Cab TLB
    FEL, MMM, Artillian 42" Forks and Modular Grapple, I-Match, Ballast Box, and lots of other STUFF.
    -John Deere 455 w/60" MMM


    Bolt on Grab Hooks and other cool stuff are now for sale!!

    Visit our YouTube Channel

    My Equipment:
    John Deere 3720 Deluxe Cab, 300cx FEL, 366 Front Blade, 59" Front Snowblower, Ballast Box
    Artillian 3K Forks, Grapple, Front-Hoe Bucket
    John Deere 455, 60" MMM

  6. The Following 2 Users Say Thank You to Kennyd For This Useful Post:

    mjncad (03-26-2018), RetiredDoc (03-25-2018)

  7. Remove Advertisements
    GreenTractorTalk.com
    Advertisements
     

  8. Top | #4

    Join Date
    Sep 2015
    Last Online
    Yesterday @ 10:07 PM
    Location
    Burton, Ohio
    Posts
    2,723
    Thanks
    530
    Thanked 433 Times in 342 Posts
    At my place of employment I ended up isolating any possible path to ground that could result from the welder power supply. I individually installed a ground rod for each welding table.
    PaDave, Robnik and Herminator like this.
    1025R FILB, vintage: 2015
    54D MM mowing deck
    Imatch hitch
    2 inch receiver for three point
    "18" cart
    Piranha Tooth Bar
    Ken's hooks and differential lock pedal
    Artillian 36" forks
    Stihl equipment: Saws; MS261C, MS462C, MS661RCM and Blower; BR600 and Trimmer; FS70R and Hedge Cutter; HL 56K and Pressure Washer; RB400
    Husky log splitter

  9. The Following User Says Thank You to Jeff B For This Useful Post:

    RetiredDoc (03-25-2018)

  10. Top | #5
    RetiredDoc's Avatar
    Join Date
    Apr 2016
    Last Online
    06-13-2019 @ 06:24 PM
    Location
    Central Savannah River Area (CSRA)
    Posts
    913
    Thanks
    162
    Thanked 144 Times in 110 Posts
    Quote Originally Posted by Kennyd View Post
    Just to be clear, are we talking about an "earth" ground or the ground lead from the welder?
    A ground to earth, like a connection between the metal of the table and a ground rod. Separate from the clamp from the welder to the piece being welded.

    I'm assuming the welder itself is grounded to earth via the elctrical outlet?

    So, a ground between the table and earth would protect me from my body beicoming the path to ground?

    What makes this difficult for me to understand is watching folks weld on cars. Unless they use a ground to earth from the car that I am missing somehow?
    1025R, H120 FEL, 60D MMM, Rhinohide canopy, iMatch, Frontier BB2060L, SS1067, RC2048, Heavy Hitch front weight carrier, subsoiler, trash bin carrier, rear hitch plate, Titan ballast box, 42 inch forks, Tarter chain harrow, Yard Tuff arena drag, DragnFly Arena Groomer, Newer Model 225 manure spreader, Ken's bucket hooks, Piranha tooth bar, Fimco 40 gallon 3pt boom sprayer,

  11. Top | #6
    PaDave's Avatar
    Join Date
    Jan 2013
    Last Online
    Yesterday @ 05:35 PM
    Location
    NW.PA
    Posts
    425
    Thanks
    146
    Thanked 107 Times in 77 Posts
    I agree 110%. I would NOT want any welding current finding a path into the building's electrical system through a fault in the welder's secondary circuit in any way shape or form.
    RetiredDoc and Herminator like this.
    3520, Sicma 74 tiller, 12Kw PTO gen, 72"auto connect deck, 300cx FEL, 61"HD w/JD toothbar & 6ft snow pusher, JD Ballast box w/Extension, Land Pride FDR-2584 finish mower,

  12. Top | #7
    RetiredDoc's Avatar
    Join Date
    Apr 2016
    Last Online
    06-13-2019 @ 06:24 PM
    Location
    Central Savannah River Area (CSRA)
    Posts
    913
    Thanks
    162
    Thanked 144 Times in 110 Posts
    Thanks for the input so far. Now I'm thinking about a way to ground the table to earth.

    My shop has a concrete floor. A thought is to drill a hole in the concrete to the dirt below, and then to hammer down a grounding rod with a connection to the table. Now I need advice on that. What diameter rod? How deep? Should the road be insulated from contact with the concrete slab? What gauge wire to use between metal table and the ground rod? Or is this even a reasonable plan?

    I've thought about hiring a licensed electrician, but the various opinions I see posted on the internet about this whole subject just shows me that among electricians there seems no consensus about what is right. I've never seen the magical NEC, but with so many interpretations of what it says out there I am really confused. Is the NEC really that ambiguous? What if I pick the wrong electrician?
    CADplans and Herminator like this.
    1025R, H120 FEL, 60D MMM, Rhinohide canopy, iMatch, Frontier BB2060L, SS1067, RC2048, Heavy Hitch front weight carrier, subsoiler, trash bin carrier, rear hitch plate, Titan ballast box, 42 inch forks, Tarter chain harrow, Yard Tuff arena drag, DragnFly Arena Groomer, Newer Model 225 manure spreader, Ken's bucket hooks, Piranha tooth bar, Fimco 40 gallon 3pt boom sprayer,

  13. Top | #8

    Join Date
    Jul 2015
    Last Online
    Yesterday @ 10:33 PM
    Location
    Near Roa. VA
    Posts
    3,579
    Thanks
    43
    Thanked 437 Times in 337 Posts
    Quote Originally Posted by RetiredDoc View Post
    Thanks for the input so far. Now I'm thinking about a way to ground the table to earth.

    My shop has a concrete floor. A thought is to drill a hole in the concrete to the dirt below, and then to hammer down a grounding rod with a connection to the table. Now I need advice on that. What diameter rod? How deep? Should the road be insulated from contact with the concrete slab? What gauge wire to use between metal table and the ground rod? Or is this even a reasonable plan?

    I've thought about hiring a licensed electrician, but the various opinions I see posted on the internet about this whole subject just shows me that among electricians there seems no consensus about what is right. I've never seen the magical NEC, but with so many interpretations of what it says out there I am really confused. Is the NEC really that ambiguous? What if I pick the wrong electrician?

    Unless water can get to that spot, the dry earth rod might be useless,,
    my BIL's shop had a loose ground somewhere,, when the two ground rods outside the shop would dry up, you would get shocked,,,

    We quickly learned, if it had not rained for a couple weeks, run the hose on the ground rods before using power tools,,
    The rods were radically different with 5 gallons of water on them,,

    (eventually, we found the loose ground,, a twist of a screw, and the shocking stopped)
    Herminator likes this.
    Some of the tractors include JD 4105, JD 855, JD 650,,,, and,,, the IH 584 4WD
    My favorite attachment is the homemade landplane,,, EVERYONE needs one of those!!

  14. The Following User Says Thank You to CADplans For This Useful Post:

    RetiredDoc (03-26-2018)

  15. Top | #9
    Fozsey's Avatar
    Join Date
    Sep 2017
    Last Online
    08-17-2019 @ 04:50 AM
    Location
    Nebraska
    Posts
    1,067
    Thanks
    212
    Thanked 165 Times in 128 Posts
    My father has been a professional welder for almost 50 years and we've never had a table grounded to a ground rod separate from the neutral going to the bus bar and I'm not aware of any specific NEC code that either reccomends or requires it. A 30 or 50 amp 220 circuit is an isolated circuit or it should be. Ill ask my pop what the industry gooroos say and edit my post.

    Update

    I had a discussion with my father, who retired from the biggest poultry and beefpackerr in the country, and he said none of their welding tables were grounded. He also said that OSHA frequented his shop regularly over his 40 plus years there and never made mention of it. I have no opinion either way. I'm just passing along info from someone knowlegable.
    Last edited by Fozsey; 03-26-2018 at 06:11 PM.
    BigJim55, Ray_PA, raco232 and 1 others like this.


    ~Brian~

    1998 425/54 Deck/650 hours | 1998 455/60 Deck/54 Blade/1300 hours | 2003 GX345 48 Deck/47 Blade/Electric Pivot/900 hours (sold)


    Yes I have an addiction and no I don't want help


  16. The Following User Says Thank You to Fozsey For This Useful Post:

    RetiredDoc (03-26-2018)

  17. Top | #10
    AlKozak's Avatar
    Join Date
    Apr 2016
    Last Online
    06-03-2019 @ 07:21 PM
    Location
    Caroga Lake, NY
    Posts
    715
    Thanks
    40
    Thanked 84 Times in 77 Posts
    The earth is a pretty crappy conductor, wet or otherwise.

    What you want to do in this case anyway is to place the table at the same potential as the electrical service ground. Connecting the return clamp from the welder to the table should do this since it is bonded to the welder case which, in turn, is connected to the electrical service safety ground (green or bare wire). Of course, you run the risk of spot welding the work piece to the table in this situation.

    You don't want a separate ground rod. You want to run your ground wire to the electrical service ground, which will be near the panel and will be bonded to a single ground rod nearby. Possibly to a copper pipe if your municipal water service is copper (I don't think this is allowed by code any longer, but was common up to the mid 80's).

    FWIW, I've never given this a thought. I weld with a portable table and have yet to be shocked.

    Cheapo buzz box welders produce maybe 80 volts with an open circuit. This may surprise you if shocked but should not be fatal unless maybe you have a serious heart condition where you shouldn't be welding anyway. Most halfway decent welders are in the vicinity of 40v maximum.

    Bottom line, I cannot think of an electrical safety reason to ground the table. But I am willing to learn!

    Al
    BigJim55, Ray_PA and Herminator like this.

  18. The Following User Says Thank You to AlKozak For This Useful Post:

    RetiredDoc (03-26-2018)

  19. Remove Advertisements
    GreenTractorTalk.com
    Advertisements
     

Page 1 of 3 1 2 3 LastLast

Bookmarks

Posting Permissions

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