Unnamed Administration sources reported that Michael Painter said:
I've laid across the buss-bars before...definitely an uneasy feeling, but never felt it unless I was sweaty. <g> Capability of thousands of Amps, but it's the old "power transfer" deal...internal resistance of the source vs. internal resistance of the load (your body).
True. It's all Ohms law. But for those of you who (unlike me) speak C and mean a language, not 3E8m/s..... let's look at 13.8v car battery and a 120v line cases. Ohms are what resist the flow of [I'll say so even though I'll wince] electrons. I = E/R. I = current, E voltage, R resistance. People are not good conductors; let's just say you have oh 100Kohm from one DRY thumb to another. Most of that is skin. Get inside the ?epidermous [sp]? and it goes down fast. Get even slightly sweaty, and same deal. So I = 13.8/100k is not much current. Not enough to hurt. I = 120v/100K is 1.2ma. That's not enough to cook you, but may be enough to screw up your heart. That's why the "one hand rule" exists. Loop one hand through belt at your ass, work with other. Iffen you get bit finger to finger on the same hand, it won't pass though your trunk. (Assuming rubber shoes...) Now, consider that dropped screwdriver. Say the total resistance of it across the contacts is 0.05 ohms. (It's dirty...) I = 13.8/0.05 = 276 A. Sparks fly. Tool melts, you hope. I = 120v/0.05 = 2400 A. Here, the 20A breaker should clear as fast as it can, and it's likely only going to be oh 1000A until it does. Still shit flies and if your eyes are in the way... Now, milliseconds later [if the fuse/breaker has not cleared] that initial current gets enough things hot, melts/cleans parts, LOWERING THE RESISTANCE as it ..improves.. the connection... Worst case, you get a plasma arc that LOVES to conduct. In that case, the resistance goes to near zero. The current is only limited by other resistances in the battery string, and you have good tight connections and large cables, right? If you are lucky, the screwdriver is consumed and the short stops. If not, well soon you get badly burnt. Wrenches are a lot more massive; and will do more damage. Some major burn cases live. I'm not sure they are the lucky ones. Short summary: 120vac line may "electrocute" you easily; a high current lower voltage system can cook you just as dead. Neither is "safe" to futz with casually. -- A host is a host from coast to coast.................wb8foz@nrk.com & no one will talk to a host that's close........[v].(301) 56-LINUX Unless the host (that isn't close).........................pob 1433 is busy, hung or dead....................................20915-1433