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Service supply lines

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  • Service supply lines

    Hello All,

    Just picked up my new welder and was going to start the installation of my electric service for the unit. I thought I could use 8 AWG like most normal 220 circuits, but I'm concerned that it may not meet the needs.

    I will be putting in a dedicated branch circuit and it will be about a 35 foot run. Does anyone have experience setting up service for this welder? Would the 8 AWG get the job done or should I look at 6 AWG or larger?

    Thanks in advance,

    Mac
    Last edited by MacDuff; 10-12-2012, 10:10 AM.

  • #2
    And your new welder is a what??

    Comment


    • #3
      I am not familiar with the term AVG but I always use 6gauge wire. Seems to keep voltage drop down with and supply voltage more cosistantly. I use THHN.
      Last edited by NathanH; 10-12-2012, 02:22 PM.

      Comment


      • #4
        Originally posted by cruizer View Post
        And your new welder is a what??
        My bad, it's the Tunderbolt XL 225/150

        Comment


        • #5
          Originally posted by NathanH View Post
          I am not familiar with the term AVG but I always use 6gauge wire. Seems to keep head down with and supply voltage more cosistantly. I use THHN.
          That should have been AWG not AVG. Do you use fuses or a circuit breaker on your disconnect box?

          Comment


          • #6
            I use circuit breakers. You could use a slow blow fuse if that is what you have in your box. You could also get away with 8 gauge wire too. But might as well do 6 as you never know what the future holds for you as far as welders go.

            Comment


            • #7
              Yep at 35' you'll need #6 to cover your bases.

              Comment


              • #8
                Originally posted by NathanH View Post
                I am not familiar with the term AVG but I always use 6gauge wire. Seems to keep head down with and supply voltage more cosistantly. I use THHN.
                AWG= American Wire Gauge

                Comment


                • #9
                  Originally posted by MacDuff View Post
                  Hello All,

                  Just picked up my new welder and was going to start the installation of my electric service for the unit. I thought I could use 8 AWG like most normal 220 circuits, but I'm concerned that it may not meet the needs.

                  I will be putting in a dedicated branch circuit and it will be about a 35 foot run. Does anyone have experience setting up service for this welder? Would the 8 AWG get the job done or should I look at 6 AWG or larger?

                  Thanks in advance,

                  Mac
                  Just in case you look at the manual and see odd wire gauge/CB recommendations:
                  50amp Circuit Breaker and Minimum #12 wire

                  This is due to the Duty Cycle of the machine. NEC allows for using smaller wire on a dedicated run and following the conduit/wire guidelines.

                  The Power cord is probably #12.

                  Anyhoo- as already mentioned if you use #6 you will definitely be set for any future machines, 100% for any machine that comes from the manufacturer with a 6-50 Plug on the end of the Power cord.

                  http://www.millerwelds.com/om/o316t_mil.pdf

                  Comment


                  • #10
                    Thanks for all the input / responses. The manual is exactly what had me baffled. I may be in for more wiring than I planned as my box in the garage is on a 50 amp breaker and it looks like it was connected with 8 AWG. It's only money and time, right?

                    Comment


                    • #11
                      An 8 feeds any machine that comes factory wired for 50A, a Tbolt of that size could use a 10 romex, the allowed 12 is for single circuit in pipe and even though its legal no one really thinks its a great idea.

                      Comment


                      • #12
                        Originally posted by Sberry View Post
                        An 8 feeds any machine that comes factory wired for 50A, a Tbolt of that size could use a 10 romex, the allowed 12 is for single circuit in pipe and even though its legal no one really thinks its a great idea.
                        I certainly concur... regardless of any exception allowed based on duty cycle, I can't imagine using any wiring smaller than AWG 8 on a 50amp C/B..

                        The C/B needs to be properly sized to protect the entire length of the feeder (e.g. nail or other failure causing a hard short in wire at some point in the future).

                        Electrical fires are so inconvenient...

                        Comment


                        • #13
                          The C/B needs to be properly sized to protect the entire length of the feeder (e.g. nail or other failure causing a hard short in wire at some point in the future).
                          This wire sizing to breaker relationship in this case (short circuit) is number 12 on a 50A. Th nail is not the situation where number 6 is sized to it. Only place that needs a 6 is oven or range, pottery kiln where the load iscontinuouss. The rest of these circuits the breaker is NOT there to protect the wire for thermal, this protection is offered in the form that the attachedd appliance cannot draw enough to overload the wire.

                          A buzz box is like this, has a number 12 cord, will not overheat any wire connected to it larger than the 12 regardless of the breaker,,,, could have 100, is not going to cook the wire in the wall,, but there are some buts,,,, some of the internals are designed to be connected to limited breakers, circuits above 50 need 10 wire, above 60 to 100 some use 8. This is for the nail scenariorio.

                          Similar to a fixture wire, the load is limited by the allowable lamp wattage, the 16 wire is not protected by thermal by a 20A breaker but sufficientcient to trip it in the event of a fault.
                          Last edited by Sberry; 10-13-2012, 07:53 PM.

                          Comment


                          • #14
                            The 8 gauge feeding the garage could be a porblem. I understand that it may be sufficent but is surely not ideal. Is the garage attached? How long of a run from the main circuit box to the sub panel in the garage? Heat is the enemy there as is voltage drop. My garage is detached and it was about a 200' run to there. When I installed the 100A subpanel in the garage I ran 1 gauge. I run 6 gauge to all 50A plugs in the garage. Keeps heat and voltage drop to a minimum. I would consider replacing the factory cord on the T-bolt also. Maybe just me, but this seemed to make a differance in performance. Smoother and easier to strike rods.

                            Comment


                            • #15
                              Originally posted by NathanH View Post
                              The 8 gauge feeding the garage could be a porblem. How long of a run from the main circuit box to the sub panel in the garage?
                              The run is about 50 feet from the main panel and the garage is attached. I'll be rewiring the sub panel in the garage with 6AWG. More of a project then I was planning, but better safe than sorry.

                              Comment

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