Greg, I've really liked your videos so far. To expand on some of your thoughts regarding the 120V being more efficient - all inverter welders do have power factor correction. I've worked as a field engineer with General Electric and Siemens for 8 years with large power converters of various constructions. All are made the same basically....AC power comes in and gets rectified to DC with storage in capacitors. On the output, the IGBTs switch very, very fast to make the desired waveform. There are some exceptions to this, but this is by far the most common way to do it. This DC-link of capacitors between the input and output is also why they tell you to wait a long time before opening up to work on it! The reason I believe the 120V is more efficient....less losses with stepping down the voltage. The input conditioning has to step 240V way way down, which causes more internal heat and less efficiency. On 120V, less step down. It does seem odd, but higher voltage is typically thought of as more efficient because of power transmission reasons (smaller conductors (wires, buss, etc); not necessarily end use application. I'm still a fan of higher voltage though. Wish I had 480V 3-phase in my garage lol.
Wow! Your ability as a teacher and welder are the best. I am blown away by your generosity to put together such a a comprehensive library of educational videos is a HUGE value to any home welder. I looked into welding classes in my area but they mostly are 600 hour cert classes that you must attend 4 days a week-4 hours a day. Great for a young person learning a career but hardly something I am looking for as a newly retired machinist tinkering in my garage. Thank you for all you do. 👊👏
Thanks for all the kind comments 😀. A long time ago I was faced with a situation where I wanted to learn to weld, but I didn't have anyone to learn from. Since my work would cover a few classes (and pay for a welding hood) I took a few classes and learned a ton. Then I continued on my journey of self teaching for years. The local community college to me offers night classes, 1 year certificate, and 2 year degree. The unfortunate reality of the community college route is that if you are a bit better than average you won't have much instructor time because there is 30 students to one instructor. Don't get me wrong, you burn up more metal and consumables in those classes than they cost, but at the same time unless you sign up for a whole degree, most of what you "learn" consists of sitting in a booth and making welds. That can be done at home with the help of youtube. My thought was to offer a lot of relevant content to the beginner welder and some motivation/inspiration so that they actually go through with practice. The accountability and structure of the formal school route is what can really help, its very easy to slack off in ones garage and not practice. That's why I am setting up some welding classes people can print and follow to help keep them on track, offer goals, and guidance to be able to learn welding. I am hoping to get a lot of people motivated to learn a new skill and believe in themselves😀 .
Excellent content! Getting into welding soon and I find your videos to be immensely helpful in translating what I read in books into practical application. Very well explained and down to earth information.
Thanks for the kind words 😀. Since you’re just getting into it expect to be pretty terrible at the start. The great thing is every improvement (no matter how small) is a improvement. As long as you focus on getting the practice in you’ll be building stuff in no time 😀. If you have any specific questions/things your struggling with feel free to ask in the comments section of any video 👍
At 240v, the supply voltage is doubled, which causes an increase in magnetizing currents. Hence, the power factor of the system comes down. I have a 12AWG dedicated circuit with two 120V outlets and one 240V. I can run all day long my 140Amp welder on 240 V but not on 120V. A 120v system is more efficient, but it requires bigger breakers and wires. For 120V you need 40 amp circuit and 8AWG wire, and also may need a bigger main breaker and wires.
You are correct. So firepower (which is now a esab brand) was a USA marketing name for a particular set of welders. They made the fire power I have, and they also made many welders for other companies (like the northern tool klutch brand). Some of the machines do have power factor correction, however this one doesn’t. Now that esab owns the brand and released the same welder as their own, they doubled the price but did not change anything. The rebel and rogue from esab have power factor correction and efficiencies over 80%.
I may be 🧐. He does have a sawzall of mine and some local brewery stickers from drinking beer here 😅. Great guy, similar disability’s to me (swearing, affinity for dangerous electrical projects, and no fear of failure), I just hide some of them better 😅.
Great! Hugely helpful and impressively detailed comparison. Seems like non-pro users aren't missing out on much by getting just a 120v welder. Really helpful info on the gauge of the house wiring being a limit on the welder. Surprising that the 20A breaker handled almost 40A without tripping, never knew that they scaled that much! This video cleared up so much. Thanks a lot!
No problem 😀. Yes, breakers have a trip curve where they can pass quite a bit of current before tripping. Far more than I would have suspected. Since welding is a sort of regulated current (aka it was pulling 30+ amps consistently and not more) the breaker was able to stay in due to the very short duration / duty cycle. No doubt it would have tripped had I tried to weld much more than I did. For fun I just looked up that specific breaker that powered the wire on the video and they claim the trip curve for 2x breaker rating (40 amps) is approximately 8-10 seconds. I welded for less than that which explains why it stayed in. At a 50amp draw it’s a matter of a second or two. The instant magnetic trip is at around 60amps. There are welders that are very tightly power regulated to not trip breakers, but most allow settings that will result in far too much current to be pulled. For the most part it’s not a issue because unless you have a improperly wired 120 circuit (14ga on a 20 amp breaker) it won’t melt anything. Running such a welder on a generator could pose a issue though, because the welder could pull far more power than the generator produces.
@@makingmistakeswithgreg Interesting. Never knew that breakers operated on a curve like that and that a 20amp could handle spikes that high. That's some really useful insights. Appreciate the reply and further info.
Greg thanks for another informative video. Your video is not the first video I saw where a dual voltage machine was drawing 39+ amps on a 120v/20Amp Circuit. Curious what the name plat rating at 120v is for I1 Max and I1 eff labeled on your welder? The reason I asked is because I recently purchased a 120v Flux Mig Welder based off false I1 Max 25A and I1 eff 19.3A ratings from their Web Site. Delivered Flux Machine rating I1 Max 42A and I1 eff 32.5A. Hindsight is 20/20, I wired a dedicated 20amp Breaker for my welder, should have gone with a 30amp service and breaker. I did have to ditch the Arc Fault/Ground Fault Circuit Breaker. Breaker would trip if I tried to Stick Weld, different machine, anything over 80Amps, with a standard 20Amp Breaker. Stick Welder I1 Max 32.5A - I1eff 19A. I can stick weld at Max 110Amps without tripping Breaker. Also, I can Flux Mig weld at highest setting without tripping breaker but who knows how long either machine will run.
So I1 max is 26 amps I1 eff is labeled as 13 amps. That is at its rated 90 amp output. Part of the problem is most welders are rated at 70-90 amps on 120 volt, which is realistic. In the manual for my welder it lists 90amps as “permissible load” and 15% duty cycle. However the welder will allow settings way over the permissible load level. The actual math of a 20 amp 120 volt circuit says that’s only 2400 watts. Well with a 100% efficient (not possible) MiG welder that would give you 129 amps of output (at 18.5 voltage). Most efficiencies are in the 50 to 65% range so literally every welder made that is above around 90 amps of output on 120 volt is relying on the breaker not tripping on thermal to be able to weld. That is precisely why the harbor freight titanium 225 stick welder only puts out 70 amps on 120 volts, because it is actually built to legit electric codes and it won’t do something silly like pull 40 amps off a 120 outlet lol. Without actually testing things there would be no way to know what’s actually going on. I have a feeling the firepower would not trip my 20 amp breaker but the long term of using it to weld even 1/8th steel on 120 volt isn’t something I would want to test. Not only is the voltage drop of the power wire feeding it a concern, but it’s duty cycle is “unrated” at those settings. I have a feeling the longevity of the welder will be at risk doing a lot of welding on 120. Or on a generator for that matter, which is something I am going to tackle in a video I am working on (welding off a generator). Realistically I think the max bang for your buck welding process on 120v is tig or stick. Tig operates at such low output voltage that you can get a ton more amperage out of it. 120-130 amps is possible on 120v which is more than enough to solidly weld 3/8th plate (multi pass). A highly efficient stick welder run with a tight arc on a 7018 could probably push as high as 95-100 amps reliably on a 20 amp circuit too. The MiG process doesn’t lend itself too well when it comes to capability on 120volt. No way are the settings I ran in the video capable of welding 1/4in steel (despite pulling 40 amps on a 120 breaker lol) yet 90 amps on a 3/32 7018 could no issue.
thanks Greg. my breaker was tripping on occasion on a 20 amp circuit with mig. I now realize I might have been using a 12 ga extension instead of the 10 ga extension cord recommended. checked my manual (everlasting 140e welder) and it specified 10 ga extension cord (if used).
No problem 😀. A 12ga cord would probably present a 5-10 volt power loss over the wall outlet voltage when the welder is running on the upper end of its ability. Which means around 95-100 volts operating on a 120v circuit. That would boost the amp draw to 44-46 amps over the probable 35-40 to output near max without the cord. Definitely enough to trip the breaker. 10 ga cord shouldn’t have much voltage drop which should spare the break trip and make the welder happy. If only 10ga cords were cheaper 😨 lol.
Nice video bud, definitely not the results that I expected. The firepower is a damn hog on 120v lol. I never would have expected it to draw 40amps. The efficiency numbers came as a surprise too.
I think most Mig welders probably wouldn’t scratch above 60-65% efficient on 120. They have to power the wire feeder, the computer/display, etc. At best I could see 33 amp draw on the low end to output around 140 amps, which is far over a 20amp breakers capability. I am shocked it didn’t trip the breaker on thermal, but I only welded at high 30 amp draw for a minute or so. No doubt it would trip it eventually. It really goes to show how limiting 120 volt power is and how important it is to have a 240 volt outlet if you want to weld anything over 1/8th in material with Mig. With Flux core you could getup to 1/4in steel on 120 volt power, so it’s the only option someone would have besides stick to get decent welds on anything over 1/8th.
