Plasma cutter and HF noise

[eseemann]

I just got my (admitted) lowest common denominator Chinese plasma cutter from Amazon and other than I need to upgrade from the 15 amp breaker I am using it works better than I thought i would. Even with this being a MOSFET cutter on a 15 amp 120 volt outlet it seems to hold its own. One small strangeness that I think might be related is that after I do some cutting I have a black screen on my PC in the kitchen. I can tell the computer is not frozen from the keyboard lights and the computer sounds but there is nothing on the screen until turn the computer off and back on again. The computer is not on the same breaker as the cutter but the computer is very close the breaker box. I wonder if a surge protector with really good EM noise filtering might help the problem. There is a screw on the back of the cutter with the "ground" symbol above it. I wonder if I should run this a ground spike along with the three pronged plug.

This is the cutter Zeny® Plasma Cutter 50AMP CUT-50 Digital Inverter 110-220V Welder Cutting Machine (CUT-50)

My goal is to get a 240 outlet installed so I can use this a 240 and upgrade my 120 buzz box to something like a Lincoln Tombstone stick welder. 

Anyone have any ideas what might be causing this or am I off base?

 

Thanks 

[arkie]

I used to have one of the HF 80 amp stick welders for small yard art stuff.  It uses a high frequency start.  I used it on a 115 VAC power feed from my main box out to the shop.  Every time I used it, it kicked off my DSL modem in the house, some 200 feet away.  I had to power cycle or reset the modem after each use of the HF welder.  Now I am using an ESAB inverter on a 220VAC feed and it no longer kicks off the modem.  It has to do with the high frequency, but I never figured out if it was due to the common ground or EMF radiation that kicked off the modem.

[eseemann]

Arkie, 

We are now at is Eseemann Crazy=maybe not! 

Thank you much. I work with a few electrical engineers and I will ask them on Monday as well. I will post any advise they have. 

 

 

[DSW]

These are the two pages from My Miller Syncrowave 200 manual that show grounding to prevent HF interference. Pretty much it's telling you to use an additional ground on all metal items as well as the unit to prevent Hf issues.

 

 

 

[eseemann]

DSW, 

Thanks for the information, I will give this a shot. I have a grounding rod outside I can use.

[eseemann]

DSW,

 

I sank a rod about 30 inches in the ground (not long enough but what I had on hand because at the last second I thought about what my wife would do to me if I broke the house by using the house common ground stake. The same thing happened and I wonder if this is due to the breaker tripping. The computer was fine when the breaker tripped twice but when I came back in the screen was blank and I had to re-start. Do you see any problem running a cutter from a 5500 watt generator if you have the right amp outlet? I have a 8 foot grounding rod I am saving for the next tornado and I will NEED the generator. 

 

 

[notownkid]

15 hours ago, eseemann said:

I wonder if a surge protector with really good EM noise filtering might help the problem.

I've been told by "Experts" never run expensive electronic without a GOOD SURGE protector, When we had an underground short on our entrance line a yr. ago everything without one got destroyed, everyone with lived another day.  All protectors were destroyed but they had done their jobs.. 

 

15 hours ago, eseemann said:

There is a screw on the back of the cutter with the "ground" symbol above it. I wonder if I should run this a ground spike along with the three pronged plug.

I have to believe they added this ground for a reason other than you ignoring it, is it going to hurt anything to ground it? I doubt it. Can you have too many grounds?  Presume Steve can tell us that.  I think you are pushing your luck at the moment with the computer. 

Just my opinion.

[eseemann]

I think this is the case in point that supports what you are saying. 

http://www.crutchfield.com/S-abIqBGbbDHs/learn/why-you-need-power-protection.html

“There was a burning smell, and the ceiling fans were hanging by a wire.”.
“A neutral wire failure,”
With no return path for the current, the two hot wires pumped 240 volts throughout J’s house. Anything that used 120 volts received twice the power it could handle. The ceiling fans whipped around at a violent speed until they burned out.

This would be what is referred to on the show Red Dwarf as "brown trousers time".

I have a good (I think) surge protector on my computer but I was thinking I might need a better protector. 

 

[SpankySmith]

Esse, I had a dedicated outlet installed for my welder, if memory serves it cost something like $50 to get installed.  Worth every penny.

[eseemann]

Who installed it, I have been wanting to do just that? What kind of welder do you have? Even at very reduced power the plasma cutter looks to be lots of fun and I would like to let it work wide open. 

 

thanks 

[SpankySmith]

I'll have to look on my refrigerator!  The guy's card is stuck there, I'll let you know when I'm back home again and can look.   I just have a Lincoln Electric flux core welder, but I had previous experience with a chop saw drawing down hard on a regular outlet, so I took the precaution of putting in a dedicated one for the welder.   Works like a charm.  

[eseemann]

Thank you much