Ron,
I for one enjoy your simplification. Thank you.

I would point out that I was surprised at an eraly age by a Bell Telephone employee who impressed me with how low a voltage was required to cause electrocution. Bear in mind the human body is essentially a sack of salted, conductive fluids... rather highly conductive, and that I can measure conductivity through it (arm-to-arm) with less than 9 volts. I am not talking about tongue-testing a transistor battery, but that too is an example.

I would suggest a welder in contact with their energized electrode does indeed have welding current throughout their body. Fortunately for them none is traveling through them to complete the circuit. I am under the impression power supply manufacturers make an effort to isolate the welding circuit from earth-ground; I may be wrong as this is not an area of any personal expertise, but please do be advised that some 4 decades ago Telco employees were teaching me that electricity less tahn 1/2 the ring voltage, lower than 25 volts, could be fatal. I never put it to the test.

In the interest of safety it's important to say especially to the uninitiated that no equpment manufacturer I know of permits handling of an energized electrode; they warn against it as a threat to life and limb.

That established on behalf of safety, I always tended to resent the cryptic representation of Watts, Amperes, Volts & Ohms (W,I,E & R respectively) as unnecessarily confusing. I am glad you avoided them.

Regards
D

Tim,
I use a Fluke 336 it is a clamp on that reads AC and DC. It has worked well for me.

CH

It's basic electricity stuff and I would have looked it up in my "cheater" book to refresh my memory so I could be accurate (and sound smart)... but after about 20 years of disuse I'm not sure where it's been put. Certainly it's nowhere to be found in my head. I wasn't trying to be mystical. I'm just trying to be stand-up and share what I do know, and what I have used in a simulated emergency radio application. Under the circumstance please accept it in the spirit intended; I apologize for lack of specificity.

I presume a 150 amp fuze will permit 149A to pass even to a dead short or arc. The issue to control (or which would cause the plan to fail) would be heat, which would be done by keeping the fuze as far from it as possible; close to the power supply.
Build a fuze of the desired rating. Gang several cheap, smaller fuzes in parallel, or steal one big 250A fuze from a kid's high performance car stereo while his back is turned... easier to build one than find one I think.

By adjusting the number and value of the fuzes, through some basic math, we can essentially build our own fuze to come close to the current we are looking for. As we slowly adjust the amperage or wire feed control higher the fuze will at some point blow and we can note the position of the dial.

All else equal, more strands of conductor build a heavier # wire which will carry more current... I'm a little foggy about computational details, but it's merely a matter of how many strands, or fuzes, we require (I am, as previously stated, unfortunately unprepared for deeper testing in that subject) I am thinking ten 25A fuzes in {series} will limit 250 A. Am I correct? {parallel connection is correct}

You can get fuzes with wire leads attaached- often called "pigtail" fuzes, and merely twist the leads together at each end to gang them, but if you solder leads onto "bare" fuzes you will often ruin the fuze.

3AG "pigtail" fuzes should cost from $0.25 to $1.25 (US$) each at the right retail source here in central NJ. Any style fuze will do, but 3AG is large enough (about 1" long) and made of {clear glass} to be easy to see and use in this application. Local Radio Shack should have something. Discount supply houses sometimes offer non-UL, chineese fuzes at about $2.00 per box of five. {NOTE DANGER GLASS FUZES MAY BURST AND SEND GLASS PARTICLES FLYING}

It so happens that fuzes are something my repair shop keeps a large selection of. They may be easier for me to get hold of than you, but in my frame of reference it's stuff already in my toolbox.

Regards,
D