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Will a 15amp outlet supply 20 amps?

Post in 'DIY and General non-hearth advice' started by Black Jaque Janaviac, Apr 21, 2013.

  1. Black Jaque Janaviac

    Black Jaque Janaviac Feeling the Heat

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    I have one of those small Campbellhausfeld stick welders. The instructions say to use a 20amp outlet when welding with 5/64" rods and the high setting. My garage has 15 amp outlets even though the wire is 12 gauge and the circuits are on 20 amp switches.

    So what is going to happen if I run it on high and use 5/64" rods on one of these 15 amp outlet? Am I only going to get 15 amps and poor performance? Or am I going to ruin the welder? Or burn my house down?

    If I put a 20amp outlet on the wall will it make it possible to use 3/32" rods? They are far more common than 5/64".

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  2. StihlHead

    StihlHead Guest

    You should match the outlet amp rating to the amp rating of the fuses/circuit breakers, regardless. The 15 amp outlets may handle the 20 amp loading (safety overdesign), but they obviously are not intended for that amperage. You are fine for 20 amps with the 12 gauge copper wiring. You will draw the full 20 amps before tripping the circuit breakers, so you could potentially burn out the 15 amp outlets. However, I have rarely seen that happen. I have seen all kinds of weird wiring remodeling houses over the years. From knob and tube with bare copper wire to aluminum connected to copper outlets (can cause a fire in time with bi-metal corrosion) to extension cords used for wiring. 14 gauge copper is commonly used for lighting circuits that are 15 amp, and 20 gauge is used for outlet wiring in the house.

    I am not sure about the amp rating using 3/32 rod, which would be 6/64, larger than 5/64 - 20 amps. The real draw on the welder is apt to vary on what type of metal you are welding and the size of the bead you are laying down. Any potential for fire, etc. is apt to be at the outlet and the welder, and not the rest of the circuit. Personally if I was welding at or above 20 amps I would oversize the supply and beef up the circuits and outlets to 30 amps. That would require 8 to 10 gauge copper wire (depending on the run length to the garage) and 30 amp rated circuit breakers and outlets.

    Note that I am not a licensed electrician in your state. Also your local or state building codes may be different there than they are here in the western US. In many cases you may be required to get a permit and an inspection for installing a new branch circuit from your breaker box, or have a licensed electrician install it. Not that that happens in many cases in a lot of homes, and in a lot of places that is not required. However... in my county it is. Oregon requires a licensed electrician to do any electrical work on a rental and any house that is listed for sale. O/w you can do electrical work yourself here with a permit. Most electrical repairs do not require a permit on existing circuits though, like swapping out a 15 amp outlet box with a 20 amp one.
    woodgeek and nate379 like this.
  3. basod

    basod Minister of Fire

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    15amp outlets are rated for 20amp pass through on a 12g 20a breaker.
    If you want full use of the welder just put a dedicated 20a receptacle in the garage
  4. begreen

    begreen Mooderator Staff Member

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    Put in a 20 amp outlet. It has heavier metal in key areas that will reduce heating of the plug socket when under load. Loop the wire under the screw lugs for a good solid connection.
    Jags likes this.
  5. jharkin

    jharkin Minister of Fire

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    I wonder if that welder can really draw 20 amps or if they are just reccomending that for safety... It would be interesting to put it on a kill-a-watt if you have one.

    True 20 amp receptacles have a t shaped neutral slot, a dedicated 20 amp plug has a corresponding horizontal neutral blade to prevent it being plugged into a 15amp receptacle. I would think if your welder absolutely had to run on 20 amps it would have such a plug.

    As others mentioned it is legal to string 15 amp receptacles on a 20amp circuit if you use 12 gauge wire. I believe the rule is you have to use a real 20amp receptacle if there is only a single outlet on the string, and can use 15amp receptacles for multi outlet circuits.

    DISCLAIMER I am not a licensed electrician, so check with your local inspector.
  6. basod

    basod Minister of Fire

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    That is pretty much what the code says - so I'll give you some DIY cred.
  7. mywaynow

    mywaynow Minister of Fire

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    If the welder is 20 amp won't it also have the flat+vertical common/neutral blades?
  8. ironpony

    ironpony Minister of Fire

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    agree with all of the above, change to a 20 amp recepticle, and if the welder truly needs 20 amps it should have the T blades so it wont plug into a 15 amp circuit.
  9. Black Jaque Janaviac

    Black Jaque Janaviac Feeling the Heat

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    The plug on the welder is just a regular 15 amp, plug with a ground. I am just going by what the instructions say. Which tell the reader to use a 20A oulet when running on High and using a 5/64" electrode.

    This may be thread drift but what has me going on this is the fact that 3/32" electrodes are more common and can be purchsed by5 lb boxes. The welder instruction manual says to use 1/16" & 5/64" electrodes and is silent about 3/32".

    I tried playing with some 3/32" electrodes made by forney. The Forney recommends 60 - 100amps for these 6011 rods. My welder is capable of 70 amp output so I thought it might work. I tested it on a piece of bedframe angle iron and it did not work.

    I have since noticed that other brands' 3/32" electrodes have a recommended amperave of 40 - 85 amps for 6011 rods. Does the amperage really vary that much from brand to brand? Should i try a different brand that has a lower recommended amperage range?
  10. Highbeam

    Highbeam Minister of Fire

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    A real lincoln buzz box is cheap if you need to use larger rods. I wouldn't spend much time or money monkeying around with getting the little 70 amp stick welder to do more than you can accomplish with the specified skinny rods.
    If you had asked, I think many would have recommended sticking with a small wirefeed welder if you're stuck with 120 volt power and/or you are welding thin stuff. Stick welding is for thick steel and thick steel requires thick rods.
    basod and nate379 like this.
  11. basod

    basod Minister of Fire

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    Depends on the welder as to the amperage. and more so the thickness of the material.
    You could get away with a thinner rod 6011 root pass and crank it up.
    Then get some 7016 for the fillets.

    3/32 rod will usually take 80-90 amps on most welders I've used
  12. Black Jaque Janaviac

    Black Jaque Janaviac Feeling the Heat

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    Yep I would like to have one of those. But even if someone gave me the buzz box, so many feet of 6 or 8 gauge wire and outlet to run 240 volts out to the garage is out of my reach. I don't think the wife would appreciate me welding in the basement.

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