Is 200A AC TIG enough ?

[stevieturbo]

As it's looking like my old machine may not be repairable, or is proving too difficult to repair...200A AC TIG, pretty much only used for DIY aluminium welding.

On occasion when welding what I'd consider large items, it would sometimes trip out ( machine, warning light, power supply always good ) but would always reset again after cycling the power, so I tended to never try and use the machine with the pedal turned to allow full power. This would generally be say an intercooler, or large item that would sink a lot of heat, 3mm end tanks kind of thing to the actual core.
Although I guess you'd think the pedal could be turned up full and you'd get some action out of the machine for a while before it'd complain ? This is the only TIG I've ever used really, so have nothing to compare. But it's been faultless until this escapade ( from 2007 )

So more recently when my woes started, trying to weld a boss onto an aluminium fuel rail. Nothing that I'd say is a big job at all ? done similar many times before without any dramas...but it's just not happening. Machine tripped and died, was repaired, returned did exact same again, repaired again, and exact same problem again, with less than 60 seconds of arc time and that was largely just trying to get a little heat into the piece, so again not even at full power. It barely started a puddle before it tripped and died.

Whilst I'm open to the possibility of needing a bigger machine....from any info I can find online, this just seems unlikely ? I'm no trained welder by any means though, all DIY. Many videos online with people welding all sorts, are just 200A machines too.

Would this small boss for an 1/8" NPT takeoff really require a ton more than 200A can handle ?

Rail itself is around 4mm thick casting and about 35-40mm diameter, just for size reference. I've no need to penetrate right through into the inside of this rail to attach it. I've welded turbo compressor housings, intercoolers, radiators, tanks etc etc and never had any real issues. But something just isn't happy now.
If I've to buy a new machine, I don't want to spend too much for say a 250, 260A machine, if it genuinely is not needed

It barely just started to get some melt going when it tripped this time. The bit that's partially welded was from October when it first happened. Discolouration is where I was working the arc around a bit to try and get some heat in first, I wasn't trying to puddle immediately.

 

[hotponyshoes]

No.
Even if you tried to weld on 50mm thick aluminium the welder shouldn't trip out.
200amps would not be enough to get a puddle going on 50mm thick Alloy but it should still hold the arc there and heat the metal up a bit until the welder overheat trips and it all shuts down.

The welder does not know what material is at the other end of the arc so should just deliver the power you are asking for.
(Some of the smart high-end stuff does have feedback but still won't trip off)

If you are thinking of replacing the welder then more amps makes a lot of difference on aluminium mainly regarding the extended duty cycle which a decent quality machine will give.

But yours sounds like it has an actual problem rather than you are asking too much of it.

 

[stevieturbo]

I'm beginning to think this myself.

I've pretty much never been able to have the pedal turned up full, and actually press the pedal full when welding, as it'd almost always trip in a very short space of time. Now those instances would have been rare, and usually towards the start of welding on a large item like an intercooler where it's taking a bit to get some heat in. I don't often do large stuff though
But the machine would always reset after cycling the power and I'd proceed again, just being a little more cautious on the pedal
As it only gets used once or twice every couple of months really, mostly on small things where it would never be any issue, it's never been a big deal

But since this problem in October, it's killing components inside when it trips. AC is dead, DC still works.

I wouldn't mind a bigger machine, but they all seem to be digital with silly buttons and screens. I'm perfectly happy with old twiddly knobs. I don't want screens and lots of menus etc. And I'm just not convinced for what I do, that I actually need bigger.
Hell I've just seen someone on YT weld a decent size aluminium sump with a 160A machine.

 

[Munkul]

I think it's your machine, I'd write it off and get another one.

Now on the subject of amps... I've welded extensively with my Lorch handytig 200 at 200 amps full bore, no tripping, no issues, nothing. It takes quite a lot of 200amp welding to even get the fan up to full speed. It just works. Yes i wish it had another 50 amps at times, but i think it does very very well for what it is, and you get what you pay for.

It also doesn't have lots of twiddly knobs, all the really clever stuff is hidden away behind menus and mostly set and forget, so all you need to do is pretty much set your Amps and it does the rest.

I'd highly recommend one.

 

[hotponyshoes]

I suppose one thing you could do is find a clamp meter and check the actual output current.
If some sort of limiting pot is set wrong inside the machine you might find you are actually getting 300amps when you press the pedal down hence why things are going pop..

Looking at your repair history I'd guess they have replaced an obviously blown component but not addressed the issue that.caused it to blow in the first place?

 

[stevieturbo]

I've sent it off again for them to look at, and included the pedal this time.

IMO there should never be a scenario where you could demand more than the machine can handle....it seems unlikely that's possible. But something is definitely up.

I'd never gave it much thought before as the instances of it happening were rare anyway

Can't put a clamp meter on it now as it ain't working lol, and obviously when using it, I'm not watching the display, so I've never actually seen what it is saying either

Hopefully they get it and can look at it to get some answers or a resolution before Xmas.

 

[JOEPRO]

I've sent it off again for them to look at, and included the pedal this time.

IMO there should never be a scenario where you could demand more than the machine can handle....it seems unlikely that's possible. But something is definitely up.

I'd never gave it much thought before as the instances of it happening were rare anyway

Can't put a clamp meter on it now as it ain't working lol, and obviously when using it, I'm not watching the display, so I've never actually seen what it is saying either

Hopefully they get it and can look at it to get some answers or a resolution before Xmas.

I think at this stage they should just provide a replacement welder but that's just my opinion.

 

[stevieturbo]

I think at this stage they should just provide a replacement welder but that's just my opinion.

My unit was bought in 2007, there is no warranty. It has been faultless until this has happened.

They have offered me a warranty unit on the basis of the repair not lasting. I'm DIY use, not having it is a minor annoyance, not critical so I told them there is no need send me over a machine temporary.. The customer service so far has been very good, I cannot complain.

And I fully understand that diagnostics and repairs are not always straightforward. Although I did think it would have been more simple than it is proving to be. It is seeming to be a unique problem they have not encountered before.

If I was using it day in, day out, then yes I would have taken their offer for a machine during repairs. But I just don't need it as essential. I don't like being without it, but it's not a big deal really.