Even with HF the arc should be established in the "right" place on the pipe joint. And if done properly there is absolutely no reason a scratch start would compromise quality in this application.

Hello Daon!

I hope the info I posted in a previous post helped...

Does this inverter have a built in HF start/HF continuous feature?
I only ask this because, I believe it's important to compare what amount of watts are being drawn from the generator into the inverter when the HF start is on - when you start to weld, and how much is being drawn from your generator with the HF completely off - when you start to weld...
When you compare these amounts to what the manufacturer shows in either their manual or what their tech support people tell you, then you'll be able to find out whether or not it's either a Generator output issue or a problem with the inner electronics of the inverter... A couple of questions should also be asked so, I hope you do'nt mind...

Have you checked the connections to see if there is an opening or area covered by electrical tape somewhere on the cables? Is the voltage output from the generator consistent? Are the input voltage "jumper links" set to the appropriate voltage inside the inverter?

One other possibility is that either your inverter is'nt properly grounded when drawing power from the generator or that the work lead from the inverter is'nt properly grounded to the work or is too far from the actual welding location or the length of the cables connected to the torch are too long which might, and I say might be affecting the HF transfer to the joint...
You also may have HF "leaking" at the junction where the welding lead or output is connected to the torch...

You really do'nt need HF start in order to start your welds like mostly everyone suggested in earlier replies to this issue... I think flatjwl made an important point about where you should start your weld with regards to the joint geometry, in order to achieve high quality welds and not worry so much about tungsten inclusions showing up in the RT's... I only want to add that alot of times in my experience, I would make sure that everything is connected properly, and that all of the torch parts, including the tungsten itself, be relatively clean, and new... To make sure that the tungsten tip is grounded properly because, if the grounded lines on the tungsten are'nt in the direction parallel to the length of the tungsten, then this also can cause arc and HF starting problems... I would also if possible, first make contact with the tungsten to the work with the power off first then, either turn the power on by the means of a footpedal or the use of a torch mounted switch or a torch mounted - fine amperage control, without making contact with the pipe... These type of torches are readily available from a variety of manufacturers... I would also make sure that I have the correct size tungsten also...
Hope this helps out... Shalom!

Respectfully,

SSBN727 Run Silent... Run Deep!!!

If this machine's power (the inverter) is coming from the auxillary power outlets from an engine driven welder it's possible that the aux gets turned off while welding. Even if the aux generator is totally independent (which it may not be) regulation in the presence of the magnetic fields induced by welding could be difficult and the designer might just shut it off to be safe. This is totally a guess just to give you a place to look.
Bill