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Hi, Obviously I'm new to the welding game, but here's my question:I found a Linde welder that orgionally ran on 3-phase power (460v). The seller says that it runs ok on 230v. Is this a possibility? It's waaaay more welder than I need, buy I think I can pick it up relatively inexpensively. I'd like something that runs on 220 anyway, but I dont really want to spend $500+ on a new one.Here is the ad posting:http://portland.craigslist.org/tls/66802489.htmlAny info that the collective knowledge of this site can provide is greatly appreciated.Andy
Reply:A three phase machine is ONLY good on three phase!!! The voltage may be switchable, as most are, but phase is not. It can be run with the aid of a phase converter, but you will need a large one, and considering the cost of both units, you could buy the right welder in the first place. By the way, you can make your own phase converter. Search Lindsey's books or on eBay for info. It is a cheap alternative that has a medium degree of difficulty.Just my opinion, not from a book, just from the road.Howes Welding Inc.www.howesweldinginc.com
Reply:Beg to differ with you, Tessdad.Both my Millermatic 250X MIG and my Hypertherm 1100 plasma cutter can be set up for either single or three phase and several different voltages. The newer Hypertherms actually "auto-sense" phase and voltage. Just plug them in and they do the rest.Cannot speak for the capabilities of the Linde. Best bet would be to try to contact the manufacturer and get an owner's manual.The phase converters such as the ones in the Lindsey books are mainly for running three phase motors. Running a welder off a phase converter is a bit more involved.
Reply:Thanks for the replys. Being an older unit, I doubt it has the ability to switch phases automatically or anything. I'll keep searching. If anyone else has any other info, feel free to chime in!Andy
Reply:Most welders dont really like Phase Converter generated 3 phase. So its better to find a welder that is made to run on single phase.Its true that many welders made in the last 10 years or so can run on single or 3 phase power. But Linde was bought by ESAB in 1985, so any welder that says Linde is usually at least that old- 20 years. If you wanted Linde manuals, ESAB would be the place to start, but I dont know how many of the really old machines they support.Unless you really have 2 phase, which I doubt- as 2 phase was only used in a few odd parts of the country, early in the 20th century. There are still neighborhoods in Buffalo NY and Philadelphia that have 2 phase, but most of the rest of the US is either single phase, or 3 phase.
Reply:I have ran a 480 volt three phase welder on 220 volt single phase and it worked fine I lost 1/3 of the rated output and had to put single phase cooling fan on it. This welder had three seperate transformers in it. One burned out so I took that one out of line.
Reply:Originally Posted by digrI have ran a 480 volt three phase welder on 220 volt single phase and it worked fine I lost 1/3 of the rated output and had to put single phase cooling fan on it. This welder had three seperate transformers in it. One burned out so I took that one out of line.
Reply:Inverter power supplies generally are capable of running off of single phase as well as three phase and are rated as such. I've heard stories about people running three-phase transformer power supplies off of single-phase, but they certainly aren't rated to do so and the weld quality is going to be suspect.-Heath
Reply:Originally Posted by halbrittInverter power supplies generally are capable of running off of single phase as well as three phase and are rated as such. I've heard stories about people running three-phase transformer power supplies off of single-phase, but they certainly aren't rated to do so and the weld quality is going to be suspect.
Reply:That's the trick with single-phase, you don't really ever end up with ripple-free DC output without significant amounts of smoothing capacitance that isn't present in a three phase welder. With all three phases referenced together, there's never actually zero voltage on the line. That's what makes three phase welders so nice. Also, there's the six-way rectifier which isn't particularly suitable for single phase applications. If it worked at all, there would probably be a serious amount of ripple in the output.-Heath
Reply:Short on capacitance huh. Sounds bad but perhaps not insurmountable. I wonder what Digr would have to say on the subject. I've got some extra capacitors from a burnt out econotig and a plasma cutter laying around. Maybe there is hope.
Reply:Hi all! That was a few years ago. but if I remember right this welder had three separate transformers each fed with a leg. All I did was to bypass the transformer that was fried and ran a leg to the two remaining transformers and set the jumpers for 220 three face and it worked fine but lost some power. The welder is still working but I will have to go and take a look and see what make it was. I believe it was a Hobart.
Reply:Thanx for the info. I'll let you know if the operation was a success.
Reply:12000,Just as a clarification, what digr is talking about is not running a three-phase welder off a single phase circuit (his mod requires no phase transformation on the power supply). He is talking about converting a three phase transformer-based welder into a single phase welder. No capacitors are needed in this type of conversion. I have heard of this being done on a lot of older transformer-based industrial welders. My understanding is that inverter-based welders are doing the same thing, but they are often pre-wired for the conversion, so all you have to do is change a few buss bars. Running a three-phase circuit off single phase is a bit trickier and like halbritt says, it is not perfect. Most solid state phase converters specifically say NOT to run a welder off it. I think most converter builders recommend a 15-25 hp rotary unit to run any type of welder. They are pretty large and HEAVY.Smithboy...if it ain't broke, you ain't tryin'.
Reply:smithboy thank's for the clarification
Reply:Thank you for your thoughts on the subject Smithboy. There seems to be some disagreement about capacitors between you and Halbritt. What I hoped to use the machine for was as a power supply for my old high frequency box and a cobramatic wire feeder for aluminum. I realize there will be a drop in power from when the setup had three phase. I intended to compensate by sticking to a thinner wire, .030 instead of 3/64. I'd like to rig it so that I can switch it back to three phase at the flick of a switch which will mean I'll have to mount a second fan (the single phase one) outside the grill and then if needed extend the tank shelf. Think it will work?
Reply:12000 doors check the fan first it most lkley will be a single phase.
Reply:Originally Posted by smithboy12000, I think most converter builders recommend a 15-25 hp rotary unit to run any type of welder. They are pretty large and HEAVY.
Reply:Actually there is no dissagreement. Halbritt is talking about phase conversion (changing the electric current out of the outlet from single to three phase.) That DOES require capacitors and more and, in the end, aint perfect. What Digr is talking about is converting a three phase transformer-based welder to use single phase by chaning the welder's internal wiring. These are REALLY different ways to get the same welder working on single phase service. In short, halbritt is talking about changing your electricity to fit the welder, digr is talking about changing the welder to fit your electricity.Rewiring the welder's internals depends on a lot of things specific to your welder. Old big stick welders were supposed to be easily converted from three to single phase with some re-wiring, but they lost some of their output...sometimes as much as half. I have seen a couple of welders that had this done, but I never did it myself. They arent rated for single phase but they work just fine at the new lower output. The cooling fan can, as digr says, be a problem. Some are single phase fans that work off one leg of the three phase power (just like regular outlets can be wired off three phase power). Others are actually three phase fans that will not run once you hook to single phase. I have welders with both kinds of fans, so don't assume anything, check. Halbritt also mentions welders that will run off both single and three phase. There are lots that do. Lots of the inverter-based welders will use either, with either an automatic or manual switch that allows it to do so. They dont just use the power (they have to adjust or be adjusted to use the power).If you want to rewire the welder you have, it might be easy or hard, depending on how much you know about electricity, that particular welder, and wiring. Even if you succeed in rewiring the welder, you may not be pleased with the amount of power you are able to get from it afterwards considering you are aiming to power an aluminum feeder. You can use a phase converter at no power loss, but it will be pretty large and probably cost many times the cost of the welder and may not give you really "clean" power. And where ever you put it, there it will be. Three phase generators exist, but are also pretty expensive and often come attached to big welders. A quick phase switch sounds neat, but maybe tough. I really dont know about that. Some here might, though. Not to sound discouraging, but it sounds like you could put a lot of work into this and even if it works, it might not work very good for what you want to do. I have an aluminum wire feeder and .030 is next to impossible to feed through a standard mig gun for more than a few seconds to a couple of minutes (without seriously good karma). 3/64 is about as small as I've been able to make work for a reasonable period of time.If all us folks that want to weld could just form a community somewhere, seems like we could get three phase power...RIGHT!? Where I live, three phase power is the same price as single phase....You just got to have a big green thing in front of your house that apparently costs a bunch of money and have a nearby pole that has three phase. Next time I move I know what I'll be looking for.Last edited by smithboy; 09-12-2005 at 11:06 AM.Smithboy...if it ain't broke, you ain't tryin'.
Reply:Actually, after looking back over the thread, maybe halbritt and I do differ on a point. I dont think capacitors are necessary when simply re-wiring the transformers to run off a single phase. They may be beneficial, but are not necessary. I bought my dad an old, old miller transformer-based dc welder that is single phase without a single capacitor in it that I have seen. I have a slightly newer dialarc 250 ac/dc. I dont think it has any significant capicatance (no power factor correction), but it looks to have pretty much the same transformer as in my dad. Both work fine. I have seen other miller three phase transformer welders with the skin off and they look like mine, but with three transformers (I think one for each phase) and this is consistent with what digr is talking about. This may be too simplistic or just plain wrong, but my understanding is that re-wiring consists of running all the transformers as if they were just one really big one, and that's why you have to drop one transformer out, because the three together draw too much current for most household electrical supplies. I'll see if I can find some more info on this. The more I think about this, the more interesting it is getting.Smithboy...if it ain't broke, you ain't tryin'.
Reply:Actually, after looking back over the thread, maybe halbritt and I do differ on a point, but not intentionally. Note, he knows a thing or two about this stuff. At first, I was thinking he was talking strictly about phase conversion which requires lots of capacitors. On that we both agree. But, also when you convert ac to dc you use some capacitors for smoothing out the current, but I dont know if they are absolutely necessary or whether my DC transformer-based welder even has them. What Halbritt says about the benefits of 3-phase DC, I didnt know, but it sounds right. I have seen other miller three phase transformer welders with the skin off and they look like mine, but with three transformers (I think one for each phase) and this is consistent with what digr is talking about. I really have never noticed any capacitors in my single phase dc welder, and I am almost positive the three phase welder had none. I'll have to give mine a good look tonight.This may be too simplistic or just plain wrong, but my understanding is that re-wiring consists of running all the transformers from the 3-phase welder as if they were just one really big one, and that's why you have to drop one transformer out, because the three together draw too much current for most household electrical supplies, otherwise you could use all three, I guess. I'll see if I can find some more info on this. The more I think about this, the more interesting it is getting.Last edited by smithboy; 09-12-2005 at 01:49 PM.Smithboy...if it ain't broke, you ain't tryin'.
Reply:Damn...Smithboy, you are right about 3-phase welders. There are three transformers. The type of circuit that we are describing is very, very simple. The transformer welder is basically a DC power supply that is comprised of a transformer or three and then a bridge rectifier. The goal is to get DC output with very little AC ripple. This is easy to accomplish with three-phase using a six-way rectifier because there are no zero-crossings. In the absence of any kind of smoothing capacitance, there is very little ripple in the output. With single-phase, there is a zero-voltage crossing 120 times per second. Once rectified this is going to produce a DC voltage with a fair amount of ripple. A certain amount of smoothing capacitance will remedy this problem, but it's also going to have an impact on the slope the welder either beneficial or not, I'm not sure. DC output completely free of ripple isn't required for welding purposes. It may be desired, but I'm not sure by how much. The capacitors that would be used for this application are quite expensive, so it's unlikely that manufacturers would use much capacitance unless it were absolutely necessary.Inverter power supplies are a completely different thing. The input AC voltage is converted into a much higher frequency voltage this can be done pretty easily regardless of phase. At higher frequencies, transformers are a great deal more efficient and the resulting output requires much less capacitance to smooth because the time-constant is so much shorter.-Heath
Reply:I'm sure my cobramtic push/pull will work with .030. Smithboy. It's the same machine I used at work to weld bent up edges of 1/8 aluminum pans to extrusions using .030 wire around the perifery of 12,000 ambulance doors (bigger wires melted the edges away). Halbritt, then maybe that I plan on running the power through an add on high frequency box will reduce the need for additional capacitance, I mean, if it works for inverter machines... What's holding me up at the moment is that my wire feeder has a burnt out circuit board I have to address before I dive in. This machine had lots of excess power when run under three phase. I sometimes even turned it way up and cut with it so I really think I can afford a 1/3 loss.
Reply:You are right about the push/pull. I guess I thought you just had a feeder with no "pull" component.About the high-freq...Are you planning to feed the wire and weld with AC current? I have never used the feeder you have, but I thought they all ran in DC only, and all the three-phase transformer welders I have seen are dc only. If you are running a dc feeder, you dont need high freq. As far as I know, high freq on aluminum is used only in ac tig applications to maintain the arc. It doesnt clean the power up...it just runs an additional current of high frequency along with the current that is already there. High freq is meant allow the current to jump the gap between the torch and workpiece without touching and, in the case of aluminum, maintain the arc without touching torch to workpiece. In DC wire feeding, touching isnt a problem. Short arc requires touching the electrode wire to the workpiece continuously as the wire filler is consumed, and becasue DC current is directional, maintaining the arc is not as much a problem as in AC tig. Also, since the electrode/wire is aluminum itself, there is no tungsten contamination in touching.I may be wrong because I dont know your exact setup, but I think all you need to do is to get the feeder feeding, and the welder up and running in single phase pumping dc current through the feeder...add argon and you are welding with wire.Just as a note, I have a high freq box on my old single-phase dialarc 250 ac/dc and I have a feeder that will run off the dialarc also (hobart hefty cc/cv). I use the high freq only when I tig, and although I have not gotten great results from my feeder with aluminum because I have no pull, it will weld beads almost consistantly with frequent birdnests as an added feature. High freq is not anywhere in the loop when I'm feeding aluminum in dc. I dont think you need more than what you already have (except shielding gas) to weld alumunum, as long as you can hack the 3ph into 1ph and repair the feeder.One additional thing, you may want to make sure that your feeder and welder will be compatible. Some feeders are cv only and some welders are cc only. You need them both to work in the same mode (cc or cv) to get smooth feeding and consistent welding. Otherwise, you will get some crazy lurching and burnbacks that make wire feeding pretty uncontrolable.Last edited by smithboy; 09-20-2005 at 10:12 AM.Smithboy...if it ain't broke, you ain't tryin'.
Reply:I think the High Freq. box was only used for weld quality but I'm not sure. I've welded without one before with a spoolamatic gun. With the box it hums more ,is a bit less spity and a lot easier to get a clean weld that looks good. The three phase power supply, high freq. box and cobramatic wire feed combo are all the original setup from work so I know they work together at least with three phases. The old Miller CP 200 power source is DC only and the high freq.box doesn't say anything on it about AC or DC.The two knobs just adjust pulse "on time" and "off time".The hi-freq boxes work with ac or dc, at least all that I have seen do. I have just never seen one in the loop with a wire welder. That's pretty interesting. I have heard of folks using dc to tig aluminum...I wonder if your setup is somehow akin to that, just using a wire feeder instead of a tungsten torch. I can't see any reason the hi-freq box shouldnt be used, except that I havent seen it used. Curiouser and curiouser. Keep us posted on this project. I am really interested in how it comes out.Smithboy...if it ain't broke, you ain't tryin'. |
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发表于 2021-9-1 01:01:34