Lincoln Idealarc Tig 300

I just aquired an older Lincoln Idealarc Tig 300 (about a 1976) in a trade. It is in great condition, and was being used in a machine shop right until I picked it up. I will be using this in my home shop to compliment my mig welder.

I also have the original manual. It states that the input power required is 230v and 132 to 150 amps. I have a 230 volt setup in my garage, but I don't know how much current it can supply. I looked at the circuit breaker and it has a double 30 amp breaker. Does this mean I can only run 60 amps?

I looked at a couple of these identical welders on e-bay, and they stated in their ads that they can be run on 230v single phase house current, and can be plugged into a range or dryer outlet. This would be the equivalent of what I am running in my garage.

So I am not quite sure if this will work propelry in my garage. I want to make sure it will work before I set it all up. Any advice would be greatly appreciated.


Reply to
Terry Gastouniotis
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Same here. I'm running that welder with a 60A breaker. Never tripped it. As far as the power factor correction caps, I think my welder has them. Are they located in the rear right side of the machine near the fan? My idling current on the primary is 30A with the contactor engaged (does this sound right?), so I agree that the 30A breaker may not be sufficient.

Reply to
John L. Weatherly

Do I detect a bit of Greece in your last name? Megara, perhaps?

I have a similar machine, slightly newer, a 300/300. With the capacitors offered with mine, you need a minimum service of 100 amps to run the machine at capacity. Without the capacitors it would be higher, but I don't recall how high right off hand. You will be able to run your machine with the service you have available, but not at rated output. You'll trip breakers if you try, but otherwise I can't imagine any harm. Maybe someone with more knowledge will chime in here. In your favor, unless you're running some pretty heavy rod, you may never have need for more amperage than you have available, although it will limit you considerably. You might consider buying a larger breaker and running heavier wire, assuming your service is large enough. Older homes are often wired with only 100 amps.

The output amperage has some relationship to the input amperage, but you have to know the output voltage before you can calculate what you're actually putting out. Your 30 amp service on the primary side may well be putting out 125 amps on the secondary, or welding side. Dunno. If so, that would permit welding with 1/8" rod. One does not add the 30 amps on a two pole breaker together. It is still 30 amps, but at 230 volts instead of 120 volts.

Good luck with the new machine. I really enjoy mine.


Reply to
Harold & Susan Vordos

Hey Terry,

"a double 30 amp breaker" only provides 30 amps, not 60. The stove/oven/range breakers here (Ontario) are 40 amp, so that would be "better" than the 30 you now have. The welder will only draw the "132 to 150" amps when you are welding to the units maximum capacity, both voltage and current settings.

Give it a go on your 30 amp circuit first and see how it goes. Keep cranking everything up and test weld until it pops the breaker, and you'll see at what point that is, and then you will know whether you have to make changes or not. Of course, a high current weld for a few seconds may not trip the breaker, where a lower setting for a continuous pass may be more than it likes.

Take care.

Brian Laws>I just aquired an older Lincoln Idealarc Tig 300 (about a 1976) in a

Reply to
Brian Lawson

I have a mid 1980s Ideal Arc 300 amp welder with the caps. I have been running mine on a 60 amp circuit and have not tripped the breaker. I have not had a need to run it above 200 amps. When I first got the machine I needed to test it to make sure it worked ok, the seller gave me 1 week to do this. When I tested it all I had was a 30 amp circuit, at 30 amps I was able to run at 140 amps in stick mode but if I used the TIG mode it would trip the breaker. If you are going to run it in AC with the High freq. running you will need the high amps to run the machine, if you run the machine at high amps DC with just the high freq start you won't need as much input current. I think IMCC you need about 20% more current for high amp AC welding with the high freq running.

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click on the link for the tig welder.

Reply to

I have the same welder in my shop .But i only have a 60 amp breaker on it.And never had a problem with it .I mostly tig with it. I never had the need to run it over 150 amps .You should upgrade yor elec. to a higher amperage. 30 amps is not very much.

Reply to

It is on a 60 amp circuit, it was on a 30 amp for testing only

Reply to

Look at the wires going to the outlet in the gargage and see if you can tell what gauge they are. Changing the breaker to a larger one is easy, but dangerous if the wiring is not big enough. Also look at how hard it would be to run new wiring to the outlet. Thirty amps might let you weld thin material, but I expect you will want to have an outlet that can supply more amps.


Reply to
Dan Caster

Yes, Greek it is. Thanks for the response. Actually I also have the Tig-300/300 welder. My home is fairly new, built in 2000. It does say in my owners manual that if I have a condensor, it requires 132 amps at 230v, and without a condensor it requires 150 amps at 230v. I am not sure if I have a condensor. Where would I look for this. You say all you need is 100 amps for maximum capacity with yours. Being that I have a new home, I guess it is possible I will have enough current to run this thing. I will give it a try. Who knows if I will weld with 1/8" rod. I have my mig that can weld 5/16" pretty easily. I have even welded 1/2" with success.

I have a couple more questions. The power cord was removed from the welder, they needed it for their new one. I am not exactly sure how to wire it up. I took off the side panel and I can see the two main connections. One is labeled H1 and the other is not labeled. But it is pretty obvious where they go. As far as the ground wire, can I just ground that to a good stud inside the welder. It looks like they might have had it connected to a stud right on the bottom inside edge of the welder, but it is missing the nut so I am not 100% sure. How do I know which wire goes to H1 and which goes to the other side?

I can figure the size of the cable I need once I determine the length I need. What size power cord are you using and how long?

I currently have 50Amp, 250V recepticals wired in my garage. Do I need to change those to 100amp or 150amp recepticles?

And finally, I have not been able to figure out how the water cooler connects to this thing. There is a water inlet connection, and then the water to the gun connection. So if I connect the output of my water pump to the water inlet on the welder, how the heck to the water come back out of the welder and back into my storage container? I'm sure it is obvious, but this is my first tig, and I am lost!

I am so close to using this thing, but I don't want to rush it and damage anything. Thanks for all the help.

Reply to
Terry Gastouniotis

At least a couple of suggestions. The machine will probably trip a 30 amp breaker just closing the contactor, no welding at all.

It will probably work fine on a 50 or 60 amp breaker, with a useful output up to around 200 amps. That is probably plenty for home shop work. At least that is my experience with a 350 amp tig/stick.

If this machine was installed commercially on a 240V circuit it would almost certainly be hardwired into a 100 amp or larger line, probably using 2 awg thhn copper that is rated up to 125 amps or so. There are no cheap plugs-receptacles over 60 amps capacity.

In your shop setting I reccomend putting a 6-50P "welder" plug on the welder and wiring it into a 50 amp breaker using suitable wire. That is far cheaper and more convenient than the alternatives, so try that and if it works, great. If you trip the breaker, deal with the problem then. If it trips a 50 it will probably still work with a 60.

This is a nice setup - you aren't "wasting" the capacity of the machine at all, as you can weld all day at 100% duty cycle, that's much nicer than a typical home shop tig/stick machine.


Reply to
Bob Powell

A 2 pole 30 amp breaker is good for -- 30 amps. I have a similar welder running from a 50 or 60 amp breaker. Input is proportional to output. The nameplate input amps is only required with the max rated output i.e. 300+ amps. I run 1/8 and 5/32 stick and Tig torch with up to 5/32 tungstens. I have never tripped the breaker. I have even used an ArcAir torch a couple times -- again without tripping a breaker. I did add some power factor correction capacitors at the welder input to reduce the input line current a little. This was apparently a standard option and should show up in the instruction manual you have.

Good luck, Mill

Reply to
MP Toolman

If you have a water cooler, you do not have to bother running the water tru the solenoid valve in the welder -- just run the water to the torch and back to the cooler. It will circulate continuously whenever the cooler pump is on. just remember to turn it on before welding. The valve in the welder would be used if you were using your fresh water supply and dumping the water down the drain. In thisa case, to conserve water you would want to turn on the water flow only when welding. That is what the water valve in the welder does.


Reply to
MP Toolman

The double 30 amp breaker indicates that you have just 30 amps. 220V house wiring is done so that each leg is hot with 110V, and each leg gets a breaker at the rated current.

To find out the capacity of your house wiring you need to look at the main breaker for the house. Whatever it says, you can't go above that without help from the power company. Unless you have electric heat its probably 100A, but you might get lucky.

Since your circuit is fused for 30 amps the sockets can stay the same. DO NOT just replace your breakers with bigger ones to get more current! The breaker will be sized for the wire, which will only be safe with

30 amps.

If you want to get more current capacity (assuming your service will handle it) you need to run a bigger circuit. From the sound of it you're not a wiring expert, so you should either get an electrician to do the job or you should do some reading on the subject before you run wires. I _do_ consider myself to be a fairly knowledgeable amateur electrician, and I don't think that I'd be entirely confident with running a 150-amp circuit without help.

Reply to
Tim Wescott

I did look at the wires wired into my house, and they are 8 gauge going from the breaker to the outlet I installed. The length of the wires is around 30 to 40 feet.

It looks as if I have 200 amps coming into the main breaker box. I will call my electric company and see if they can confirm it. But that's what it says right on the large breaker switch where the main power is comming in.

The shop I picked up the welder from was also running 8 gauge wire from the main panel to the welder with a 100amp breaker. But they were only running about 15 feet of it, and it was hardwired right into the welder. They actually have the exact setup with their new lincoln tig without any problems.

I don't think I would trust the 8 awg wire running over a length of 30 to 40 feet in my garage with a larger circuit breaker. Especially since it is stapled to the wood frame of the house behind the drywall. It is simple enough for me to run a larger gauge wire through some conduit from my circuit breaker to the welder. It is basically a straight shot up one wall, across the ceiling, and down another wall. I just need to calculate what wire size I need for the breaker I run. I should probably just stick in the largest breaker they make for my panel, like a 60 or 100amp.

Any comments on using my existing 8 gauge setup with a larger 50 or

60amp breaker? I probably won't do it unless others have done this without any problems.

Thanks again for all the help.

Reply to
Terry Gastouniotis

Don't do it.

Let me say it again, don't do it. I'm sure that the company that sold you the welder had no problem with their wiring. I could have 4 bald tires on my car and not have a problem as well. You are setting yourself up for a world of hurt if you wire it wrong and your house burns down or someone gets hurt.

Here's an ampacity chart so you can look it up the wire gauge yourself:

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Reply to
Jim Stewart

When feeding a welder the NEC allows smaller than normal supply conductors. The conductor sizing is based on the welder's nameplate primary current and duty cycle. If the conductors are sized with this method the breaker can be

200% of the welder's rated primary current.

So it's quite possible that the hookup where you bought the welder was up to code. Whether this is a wise thing to do in a residential setting is another matter.

Ned Simmons

Reply to
Ned Simmons

I am completely aware of the consequences. I pretty much had my mind made up on running new wire from my breaker box to the welder, through condiut. I like to do things once, and the right way. That's why I'm asking these questions.

One last thing, should I match the wire size to the breaker I choose. For example, many people say they are using 60amp breakers for this particular welder. Should I use wire gauge for 60 amps of current which would be 4 awg of the TF / UF wire, or should I choose the wire gauge of 150 amps which is the maximum the welder will ever draw.

Does the duty cycle have a play in the wire size. I know I will not be welding at 100% duty cycle. Is there a correction factor that I can apply in figuring the wire size if I were welding at 60% duty cycle which I think is the maximum the welder can handle.

Well, thanks for the chart. Saves me having to calculate the sizes. I just need to decide on what breaker to run and the wire size, and I should be up and running.

Reply to
Terry Gastouniotis

Good plan. Pulling 6 or 6 awg wire is a pain and you only want to do it once.

I can see no reason to size the wire greater than the breaker over the distance you're going to run.

Others have pointed out that the NEC allows for undersized conductors feeding a welder. I was not aware of that. You still have to make sure that it passes code in a residential installation and that someone else doesn't misapply it in the future. I know that in my town, the building inspector does not allow it.

Reply to
Jim Stewart

I went to the NEC web page and was looking for 70-20 article 630

I went to the NEC web page and was looking for 70-20 article 630 which supposedly talks about welders. But I couldn't find it on-line. I don't know if this needs to be purchased or if the info is available over the web.

The 200% number came up on the NEC's message board, and I am a bit confused. The primary current of the welder is 132 to 150amps (at least that is what the source current is if that is what were talking about). So unless I am looking at this incorrectly, the breaker I would need would be 200% of 150 amps, which would be a 300amp breaker? It seems that this is backwards. You stated that when feeding a welder NEC allows for a smaller than normal supply conductor. So why the huge breaker?

Reply to
Terry G


I just emailed you the pertinent section from the NEC, assuming your email address is not munged.

As I read it, the code is prescribing a *minimum* for the conductors and a *maximum* for the breaker.

I've owned a couple Miller 330APBs, which are comparable to your machine. As others have said, they would run fine on a

50-60A circuit until you want to turn up the current. In my case the only time I ran into that was welding 1/4"+ aluminum or arc gouging. I never had a problem on a 100A circuit.

Even though the welder may work OK for your purposes on your 50A circuit, and the conductors are protected by the breaker, it's possible that they don't meet the requirements of section 630-11, depending on the welder's ratings.

Ned Simmons

Reply to
Ned Simmons

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