Adding new circuit to a panel.

[Jeff Wisnia]

I've tried to follow the "One arm behind my back" adage when working around dangerous voltages, and I'm still around, so I guess it works. I don't think I've ever gotten a shock through my chest, but I've had some pretty good ones through one hand.

The "shock" I've never forgotten was received when I was doing TV repair as a kid and was schlepping a 19" B&W TV chassis down a flight of stairs from a customer's second floor apartment. I'd forgotten to discharge the multi KV high voltage stored in the capacitance of the CRT. Somehow, part of me got zapped by that voltage and the chassis flew out of my arms and down the stairs, with the CRT imploding en route. The boss had to buy the customer a new TV, and after that experience I always treated CRTs like they were running chainsaws.

But, I started playing with electricity back in the era when electronics were all vacuum toob stuff, where ac and dc voltages in the 150 to 1000 volt range abounded. Things got quite a bit "safer" when solid state circuits took over. Nowadays sticking your fingers into "live" stuff is more likely to damage the equipment (through static electric discharges) than hurt you.

Thanks for the mammaries...

Jeff

[Goedjn]

Buy the "wiring 123" book at home depot, read the entire thing, Check with your local town hall about where, how, and if you should get a permit, and how much it will cost, and then check back if you have any more questions.

[Mark Lloyd]

It's actually the current that matters. 30mA (.03A) is fatal. Current is voltage divided by resistance (you might want to try measuring the resistance of your body sometime. Try it both dry and wet).

I remember measuring 2K ohms across my body (when dry). 120V across that would produce a current of 60mA. Good thing I've only had that between fingers of the same hand.

[Mark Lloyd]

I found an outlet miswired that way when I moved into this house. Maybe someone thought it didn't matter. That outlet was next to a bathroom sink, and I was replacing it with a GFCI anyway.

[nlbauers]

Years ago in an EE lab my lab partner was working on the 120 VAC power section of our project. All of a sudden, I hear BANG, my partner jumps out of his seat, and the entire bench goes dead. Turned out the guy had INTENTIONALLY placed a penny between the bare 120V leads. The current had blown two divots in the penny before tripping the breaker. "I thought it would just warm up the penny a little." he murmured.

Come to think of it, I didn't see him around the EE department much after that.

[PipeDown]

More likely touched one buss bar and the grounded cabnet but there are plenty of spots whrere both busses are only an inch apart or less.

[ng_reader]

Actually poster #1 was right. I only touched one side, so maybe that's why it didn't feel any different. Does it, btw?

[Tony Hwang]

Hi, Hmmm, don't know about 440V but I use to check 120V with my two right hand fingers. I don't do it any more. Tony