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Thread: 20amps??? Or 30amp breakers???

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    20amps??? Or 30amp breakers???

    Just wondering about power requirements for a lot of the 120v welders I am seeing. Some of the manufacturers recommend 30amp breakers to keep it from tripping too often. But is that even safe to put a 30amp breaker on a 20amp plug? I am not too knowledgeable about electrical to know.

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    Re: 20amps??? Or 30amp breakers???

    Quote Originally Posted by Ch4p View Post
    Just wondering about power requirements for a lot of the 120v welders I am seeing. Some of the manufacturers recommend 30amp breakers to keep it from tripping too often. But is that even safe to put a 30amp breaker on a 20amp plug? I am not too knowledgeable about electrical to know.
    It's not the plug that's the problem, it's the wire. You need to run new wire with a larger breaker.

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    Re: 20amps??? Or 30amp breakers???

    From my experience you should be fine with a 20amp breaker as long as you aren't using an extension cord. If you have to get that extra length make sure you get a cable that won't cause too much resistance. I wouldn't go over 50 ft of cord with 10 ga solid copper wire. For a 25ft or shorter run I can usually get away with a 12 ga cord. As TraditionalToolworks said, wire size is important. If you replace a 20a breaker with a 30a breaker but leave the wiring the same it could be a fire hazard due to the original wiring causing too much resistance for the increase in amperage.
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    Re: 20amps??? Or 30amp breakers???

    Thanks for the feedback guys.

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    Re: 20amps??? Or 30amp breakers???

    IF the machine will be maxed out, definitely go with 30 amps. The duty cycle will be an issue too.

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    Re: 20amps??? Or 30amp breakers???

    They make 30 amp 120 volt.
    But I would look at dryer plug lower in cost it made 4 wire but you only need to use one hot leg. This saves money and pick from local hardware stores.

    There also RV plugs too. But last I check they cost more but they are 30 amp 120 volt 3 wire.

    I would run 4 wire 10 gauge wire it cost a little more today but upgrade later the wiring is done.

    Dave

    FYI you happier with the 30 Amp for welding the 20 amp will flip a lot per day.

    Quote Originally Posted by Ch4p View Post
    Just wondering about power requirements for a lot of the 120v welders I am seeing. Some of the manufacturers recommend 30amp breakers to keep it from tripping too often. But is that even safe to put a 30amp breaker on a 20amp plug? I am not too knowledgeable about electrical to know.

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    Last edited by smithdoor; 4 Weeks Ago at 12:10 PM.

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    Re: 20amps??? Or 30amp breakers???

    As was said, 30 amp is a great way to go. The 20 amp circuit is limited to about 90-100 amps output from the welder. Unless it's an inverter, may get a little more.

    Dedicated circuit (only one plug-in) is the correct way to do it.

    Keep the same plug and wire the machine has on it, wire the receptacle for 30 amps and call it a day

    The machine can't use all that power very long without overheating anyway - so the circuit will have plenty of time to cool down.
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    Re: 20amps??? Or 30amp breakers???

    I agree
    When look same welder in UK it use a 13 amp 220 breaker which is 2,860 watts.
    If calculated for 120 volt you need a 24 amp breaker good luck finding a 25 breaker today next step up is 30amp. My solution was buying a 240 volt welder now I am happy no more trips to breaker box.

    Dave

    Quote Originally Posted by MinnesotaDave View Post
    As was said, 30 amp is a great way to go. The 20 amp circuit is limited to about 90-100 amps output from the welder. Unless it's an inverter, may get a little more.

    Dedicated circuit (only one plug-in) is the correct way to do it.

    Keep the same plug and wire the machine has on it, wire the receptacle for 30 amps and call it a day

    The machine can't use all that power very long without overheating anyway - so the circuit will have plenty of time to cool down.

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    Re: 20amps??? Or 30amp breakers???

    Quote Originally Posted by Asben Welding View Post
    From my experience you should be fine with a 20amp breaker as long as you aren't using an extension cord. If you have to get that extra length make sure you get a cable that won't cause too much resistance. I wouldn't go over 50 ft of cord with 10 ga solid copper wire. For a 25ft or shorter run I can usually get away with a 12 ga cord. As TraditionalToolworks said, wire size is important. If you replace a 20a breaker with a 30a breaker but leave the wiring the same it could be a fire hazard due to the original wiring causing too much resistance for the increase in amperage.
    Do not use solid wire for a portable extension cord. It isn't designed to flex like a cord under repeated use.
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    Re: 20amps??? Or 30amp breakers???

    Quote Originally Posted by TraditionalToolworks View Post
    It's not the plug that's the problem, it's the wire. You need to run new wire with a larger breaker.
    Unless you know what wire was used, the length of run and the machine there is no way you can make that claim with any certainty.

    Dedicated welder circuits fall under different rules in the NEC. So, if he dedicates the circuit to just a welder it would allow going up in breaker size for a given wire size. In many cases you can double the breaker size, so even a normal home circuit with 14-2 wire would be fine with a 30A breaker.
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    Re: 20amps??? Or 30amp breakers???

    NEC for
    14 gauge is 15 amps
    12 gauge is 20 amps
    10 gauge is 30 amps
    8 gauge and up you see chart for amps

    Dave

    Quote Originally Posted by G-ManBart View Post
    Unless you know what wire was used, the length of run and the machine there is no way you can make that claim with any certainty.

    Dedicated welder circuits fall under different rules in the NEC. So, if he dedicates the circuit to just a welder it would allow going up in breaker size for a given wire size. In many cases you can double the breaker size, so even a normal home circuit with 14-2 wire would be fine with a 30A breaker.

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    Re: 20amps??? Or 30amp breakers???

    Quote Originally Posted by smithdoor View Post
    NEC for
    14 gauge is 15 amps
    12 gauge is 20 amps
    10 gauge is 30 amps
    8 gauge and up you see chart for amps

    Dave
    Those are right for general use.
    For specialty use like dedicated circuits for welders, the amps can vary based on the welder duty cycle.

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    Q. How do I size the conductors for an arc welder?


    A. The supply conductors for arc welders must have an ampacity not less than the welder nameplate rating. If the nameplate rating isn't available, the supply conductors must have an ampacity not less than the rated primary current as adjusted by the multiplier in Table 630.11(A), based on the duty cycle of the welder.

    Ecmweb Com Nec Code Qa Duty Cycle Table
    Let's work an example problem to help hit this point home.

    A non-motor/generator arc welder has a primary current rating of 40A with a duty cycle of 50%.
    Calculated Load = Primary Rating x Multiplier [Table 630.11(A)]
    Calculated Load = 40A x 0.71 = 28.40A

    Therefore, the branch-circuit conductor for the welder must not be sized less than 30A. As per Table 310.15(B)(16), a 10 AWG conductor has an ampacity of 35A at 75șC.
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    Last edited by MinnesotaDave; 4 Weeks Ago at 02:39 PM.
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    Re: 20amps??? Or 30amp breakers???

    Quote Originally Posted by Oldendum View Post
    Do not use solid wire for a portable extension cord. It isn't designed to flex like a cord under repeated use.
    +1

    I'd use SOOW. Look on ebay for good prices. (I think one vendor there with good prices is called "AC/DC" or something like that.)

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    Re: 20amps??? Or 30amp breakers???

    It is true that the duty cycle limits the length of time the machine can be run so while it isn't standard wiring procedure putting 30 amps on 14 gauge you do so.

    For small stuff just always best to just run the correct wire for the ampacity of the overcurrent protection. A quality 20 amp receptacle will be fine though as would the cord and cord cap the machine came with.

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    Re: 20amps??? Or 30amp breakers???

    Quote Originally Posted by G-ManBart View Post
    Unless you know what wire was used, the length of run and the machine there is no way you can make that claim with any certainty.
    I absolutely can.

    What is certain is you can't guarantee that no person will plug in any type of electrical device that will require the full amperage of a 30 amp circuit. What you (And Dave J) mention applies only to the duty cycle of a welding machine, not any other electrical device. A receptacle can't determine what a person will plug into it, that much is certain. This is also why the receptacle should be replaced to the proper amperage rated receptacle.

    EDIT: It's true I don't know what wire a 20 amp circuit used, but going by code I'm guessing it used the proper gauge for the circuit, in fact I have not seen many that used large gauge wire. Maybe you have a different experience.
    Last edited by TraditionalToolworks; 4 Weeks Ago at 05:07 PM.

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    Re: 20amps??? Or 30amp breakers???

    Quote Originally Posted by Ch4p View Post
    Thanks for the feedback guys.

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    Clear as mud yet?


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    Re: 20amps??? Or 30amp breakers???

    Quote Originally Posted by TraditionalToolworks View Post
    I absolutely can.

    What is certain is you can't guarantee that no person will plug in any type of electrical device that will require the full amperage of a 30 amp circuit. What you mention applies only to the duty cycle of a welding machine, not any other electrical device. A recepticle can't determine what a person will plug into it, that much is certain.

    EDIT: It's true I don't know what wire a 20 amp circuit used, but going by code I'm guessing it used the proper gauge for the circuit, in fact I have not seen many that used large gauge wire. Maybe you have a different experience.
    Unless you've been to his place and seen the setup, and the machine (or specs for it), you're guessing. That would still require you to know the correct NEC section...which obviously isn't something with which you are familiar.

    Dedicated outlets for non-continuous loads like a welder have their own set of rules in the NEC, as quoted above. The outlet and breaker panel need to be marked as a dedicated circuit so someone doesn't use them incorrectly.
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    Re: 20amps??? Or 30amp breakers???

    Quote Originally Posted by G-ManBart View Post
    Dedicated outlets for non-continuous loads like a welder have their own set of rules in the NEC, as quoted above. The outlet and breaker panel need to be marked as a dedicated circuit so someone doesn't use them incorrectly.
    That's my understanding, as well. See NEC article 630.11

    ETA: Never mind, I guess Dave posted it.

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    Re: 20amps??? Or 30amp breakers???

    Quote Originally Posted by Broccoli1 View Post
    Clear as mud yet?


    Haha I'll drink to that!

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    Re: 20amps??? Or 30amp breakers???

    yea, I already knew this was going to be a pretty complicated discussion. Thanks for all the information guys. It helps clear upsome questions I have. Just need to make sure I am safe to weld at home before I proceed.

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    Re: 20amps??? Or 30amp breakers???

    Best way is install a dryer plug

    Dave

    Quote Originally Posted by Ch4p View Post
    yea, I already knew this was going to be a pretty complicated discussion. Thanks for all the information guys. It helps clear upsome questions I have. Just need to make sure I am safe to weld at home before I proceed.

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    Re: 20amps??? Or 30amp breakers???

    Breakers or fuses are there to protect the wire. End of discussion.

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    Re: 20amps??? Or 30amp breakers???

    Breaker do need replace when flip
    Time delay fuse works better on Arc and Mig welder has the take a high current load about 3 or 4 times the fuse protection.

    Dave

    Quote Originally Posted by theweldor View Post
    Breakers or fuses are there to protect the wire. End of discussion.

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    Re: 20amps??? Or 30amp breakers???

    Quote Originally Posted by Oldendum View Post
    Do not use solid wire for a portable extension cord. It isn't designed to flex like a cord under repeated use.
    I did state that pretty poorly. I was intending it to be read as only copper. I've seen a ton of cheap drop cords that are copper over aluminium and they suck in my opinion. The Aluminum doesn't have the same capacity(?) as the copper.

    Thanks for pointing it out to me, wouldn't want to spread bad info! I'll throw an edit up there.
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    Re: 20amps??? Or 30amp breakers???

    Found out you can't edit a post, still learnin' the ropes.. Hope this works.

    Quote Originally Posted by Asben Welding View Post
    From my experience you should be fine with a 20amp breaker as long as you aren't using an extension cord. If you have to get that extra length make sure you get a cable that won't cause too much resistance. I wouldn't go over 50 ft of cord with 10 ga braided, fully copper wire (No Cu/Al). For a 25ft or shorter run I can usually get away with a 12 ga cord. As TraditionalToolworks said, wire size is important. If you replace a 20a breaker with a 30a breaker but leave the wiring the same it could be a fire hazard due to the original wiring causing too much resistance for the increase in amperage.
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