I just bought my first welder, a new Dynasty 200DX. Reading through the owner's manual, as well as a couple of TIG books published by Miller, I see the diagrams of HF interference and best practices of grounding the body of pretty much every metallic object within a radius of 50 feet of the HF source - the welder. But none of the literature explains what types of actual problems could result from not doing this.

I am putting the welder in a free-standing, fully finished workshop about the size of a 2-car garage, with its own 200 Amp electrical service from a mast, garage door, AC heat pump out back with air handler in the attic, fridge, TV, etc. All of these items are grounded through their electrical wiring and the building's electrical system which I wired myself. I used two 8 ft grounding rods, installed per code.

My questions are:

1) What are the possible problems if I don't take any additional measures to
ground these objects, and I use the welder in DC mode with HF start only?
Will my TV, fridge, A/C equipment be damaged?

2) Will this equipment, if it is running, interfere with the welder's ability?

3) Will this only be a concern in AC welding?

Thank you.