185 Micro HF?

[Gtig]

I should be getting my 185 Micro by next week and I have some what a large welding job at a hospital already lined up. I think I know the answer but is there away to disable the HF start (need to weld 316L SS) more like lift start? Other welding jobs in the past I had to disconnect some of the control boards and I/O boards so the HF start won't wreak havoc on them but this machine I'm welding is twice the size and allot of connectors to disconnect. I can disconnect the cables if need be but it's a big pain in the you know what. Also on the 185 I've notice there is grounding lug in the back, has anyone used that to connect to earth ground? To relieve some stray current or mostly HF?

Thanks,
GTIG

[Ray]

Hmm, I suppose the Hf could be disabled inside the machine, and lift start used. Although I would be concerned about the welding process in general taking place with electronics sharing the ground. Usually when welding on equipment any more I disconnect all computers radios etc.

The ground stud on the back is to afford an additional ground away from the electrical service panel, to reduce Hf feedback to things like computers, lighting and similar.

If you want to call me I can help you identify the Hf supply, you could put a switch in there to make it selectable.

[performance]

If it were disabled, it would only be a scratch start, and not lift start. This unit has no lift start capability. There is a difference.

[Gtig]

Thanks for the replies gentlemen! The more I thought about I'm just going to leave it be and not do anything that will void my warranty. I have been doing this for a long time and this particular welding job is very rare so I'm just going to take the time and disconnect the connectors and jumpers that may have a problem with HF.

I need to weld some long beads with the 185 so it will be put to the test here in a week or so. Need to run some 28 gauge SS strips inside a washer chamber around 20' or so. I'm hoping that I can convince the maintenance department there to run me a temp 220V circuit if not I'll be forced to use 110V. Wish me luck!

GTIG

[Ray]

If it were disabled, it would only be a scratch start, and not lift start. This unit has no lift start capability. There is a difference.

No it would be lift start.

The unit has the same current hall that starts the arc after current flow is detected, normally used to transfer from Hf to welding arc. Same as say the 250EX.
With scratch start the electrode is hot from the get go.

[performance]

Ray, ... Lift start doesn't have anything to do with being hot or not. On the 140, the current is hot all the time and there is no switch. On miller inverters, such as the 304 and the maxstarts, scratch start and lift start both work without the use of a switch. I have used the XMT models for hundreds of hours in both modes. The tip is live, but when it senses contact with the metal, it reduces current flow, and when it lifts up it sends a burst of power down the line to start the arc. I also have used it for welding on bobcats as well. The 185 may start as a lift start without the HF, but it definitely doesn't have anything to do with it being live all the time...both may or not be controlled with a torch switch to energize.

[Ray]

Ray, ... Lift start doesn't have anything to do with being hot or not. On the 140, the current is hot all the time and there is no switch. On miller inverters, such as the 304 and the maxstarts, scratch start and lift start both work without the use of a switch. I have used the XMT models for hundreds of hours in both modes. The tip is live, but when it senses contact with the metal, it reduces current flow, and when it lifts up it sends a burst of power down the line to start the arc. I also have used it for welding on bobcats as well. The 185 may start as a lift start without the HF, but it definitely doesn't have anything to do with it being live all the time...both may or not be controlled with a torch switch to energize.

Yes, I was being brief with the explanation. And misstated what I meant by “live” the tip is hot but not exposed to full inverter output. The initial current is limited by a fixed resistor and monitored by a current hall or amperage detector if you will. When conductivity is detected the power control transfers from a set value to the current control circuit, this is also the point the Hf is disengaged if active. The effect is the same whether the arc is started by the Hf ionizing the argon and starting conductivity or by contact with the tungsten to the work piece. The purpose is to prevent blowing a hole from the arc surge when the Hf is active or sticking the tungsten to the work piece in the case of a lift start.