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extension cord

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  • extension cord

    I bought a Millermatic 211, the outlet in my garage is fed by 6 Guage wire,
    is it ok to use a 8/3 extension cord from 25' to 50'

    Thanks for any help

  • #2
    Yes it is ok, you could use a 12 cord with that machine.

    Comment


    • #3
      Manual says 14ga OK

      The manual, on page 17, says that a 14 ga cord is adequate. Maximum length 53 feet. The maximum current rating is 25 amps.

      I figure that they must be taking into account the duty cycle of the welder, as a 25 amp load would usually require a 10 ga cord. This is all per the National Electrical Code, which has a welder exemption. Personally, I probably would use a heavier cord than 14ga.

      Richard



      Originally posted by tlhouston View Post
      I bought a Millermatic 211, the outlet in my garage is fed by 6 Guage wire,
      is it ok to use a 8/3 extension cord from 25' to 50'

      Thanks for any help

      Comment


      • #4
        The manual is for those fluent in code and nema. This machine may be ran on circuits to 50A provided the wire is a size bigger than the minimum,,,, with the 14 its 35A, with 12 or better 50A which is the plug comes on it. The unit has a 12 cord just to allow for it to use the larger circuit. It has its own thermal after the switch to protect it against overheat and for the finer wire within the unit. This will open before the unit will draw enough to overheat the incoming cord or even a 12 wire on a 50A.
        Last edited by Sberry; 12-06-2013, 04:01 PM.

        Comment


        • #5
          The manual is terrible since this is marketed to a diy crowd, it should have lay language also and a recomentation above the code minimum which would get rid of confusion and no one thinks its a good idea to put this on a ******* 14 wire to a 50A recept.

          Comment


          • #6
            I totally agree sberry. It's funny how many threads get started on here asking basically the same exact thing. Miller should just say to run 25' use x gauge, to run 50' use x gauge, etc.

            Comment


            • #7
              Originally posted by raferguson View Post
              The manual, on page 17, says that a 14 ga cord is adequate. Maximum length 53 feet. The maximum current rating is 25 amps.

              I figure that they must be taking into account the duty cycle of the welder, as a 25 amp load would usually require a 10 ga cord. This is all per the National Electrical Code, which has a welder exemption. Personally, I probably would use a heavier cord than 14ga.

              Richard
              The resistance of 106' of 14g is .268 Ohms. The voltage drop at 25A is 6.7V.
              The power dissipated at 100% duty cycle is 167W. However, the MM duty cycle at 25A input current is 30%. So, in practice, the cord would dissipate 50.1W or about 1 W per foot. What d'ya know! Those Miller guys was right! Moral: When all else fails read the manual. When that fails follow the manual

              Comment


              • #8
                Yes, it is amazing how informative a manual is . Like instructions supplied with a product, when it doesn't fit or look like right, read the instructions.
                There are so many knowledgeable members here that they should be writing the manuals.

                Comment


                • #9
                  "When all else fails read the manual. When that fails follow the manual"

                  LOL, I'll be using that for the rest of my life.

                  Comment


                  • #10
                    The only problem with the manual in this case is that its not clear. It implies that this machine needs to be limited with a breaker of 35,,,, it does if,,,,, you use the minimum wire. Once you up the wire it can go on a common 50A welder circuit.

                    Comment


                    • #11
                      There is a problem due tio the fact so many machines with different demands can be plugged in to a 50A circuit, some allow a 12 wire and some an 8. A true 50 for a range or oven a 6 but it uses a different recept.

                      Comment


                      • #12
                        what size breaker

                        You are probable plugging this into a 30 amp or a 50 amp circuit and leave it plugged in most of the time. I cannot duplicate the math for the 14 guage wire, so I might stay on the safe side and use a 10 gauge cord. My concern is that a 14 gauge wire could burn pretty good in a fault and not trip a 30 amp breaker or a 50 amp if you use a typical welding circuit. It would take a direct short to do it. You can shop for a 10 ga 120 volt 3 wire extension cord and change both ends. Sometimes cheaper. I might say that every time I built a 50' cord I found it too short.

                        Comment


                        • #13
                          You're good

                          You're fine. In the house circuit you need at least 8 ga. Wire and a 40 amp breaker. At a minimum you need 14 ga for 15 amp circuits, 12 ga for 20 amp circuits, 10 ga for 30 amp circuits, and 8 ga. for 40 amps. You should use a 40 amp breaker for your 30 amp (power input max) welder.

                          Comment


                          • #14
                            Some circuits can use a 14 wire on a 30A breaker, some 12 wire and a 50.

                            Comment


                            • #15
                              Not really

                              The purpose of a breaker is to protect the wire, not the extension cord or the welder. You MUST size your wire for the max power the breaker will allow to pass. That means if you are using 12 gage wire nothing greater than 20 amps draw. Your welder draws nearly 30 amps, so 12 gauge wire is INADEQUATE and presents a definite fire hazard and wouldn't be allowed by any inspector in the land. If you are going to pull 30 amps (more or less) from the circuit the minimum breaker you will require will be a 40 amperage, and it will require 8/3 wire in this case. Also, because there is no neutral connection in the receptacle you will be using and because the ground wire is normally smaller than the other wires in the cable you will want to substitute the neutral wire for the (bare) ground wire you will need to identify having done so by putting a band of green tape on each end of your white wire. Otherwise you run the very likely risk of frying the wire and the possibility of burning the place to the ground.

                              Do not skimp on wire size! It is at best false economy and always a safety hazard.

                              Comment

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