Electric Shock Hazard

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We wish to spot weld a .010" thick by .1" wide X 3"long titanium strip to another sheet of titanium. The problem is that the geometry involved makes it difficult to fixture. We want the operator to do it by hand. What are the safety issues? What would typically happen if the operator touched the electrode with one hand and the ground with the other hand and activated the weld by pressing the foot pedal. (You won't be held liable for any advise given, of course)

-- Steve Hantman (shantman@provenprocess.com), September 06, 2002

Answers

There is very little electrical shock hazard with resistance welding, as the average voltage is 12 volts, like a car battery. There is a great amount of energy involved, 10,000 watts at the weld, 100,000 watts at the transformer (sorry about the 90,000 watts lost as heat...) so the operator must be protected from any weld expulsion that may occur. There is a great hazard from the 600# force of the tips, of course. Particularly when it is concentrated into a 3/16" spot, thats over 20,000 PSI! Most automatic operations prohibit the operator from having a hand free to put into the machinery, that is why they have the dual palm buttons. You MUST protect the operator from this.

-- David Bacon (dbacon@updatetechnology.com), October 03, 2002.

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