High voltage can also kill you, even if the current is small. It electrolyzes the water in your body, creating atomic oxygen, which oxidizes the body cells. It is as dangerous as if you pump air in your veins with a syringe.
(random) I was sitting alone on the third floor at work a few years back, and was testing a computer I was reassembling… reaching about, I absent-mindedly did what I usually did, and felt for the prongs on the power supply wiht my fingers, and finding it, plugged the power cord in. Mistake #2… power cord was still plugged into the power strip. This was an old PC, and I completed the circuit between the power supply and cord… Regardless of how powerful it is, it is not fun. Thankfully, society is so advanced that we actually have ways to TEST for a live current, believe it or not.
Since I seem to have started this, I should point out that “touch and swear” is not my preferred method of testing a hot lead. Once, I was changing a light fixture in a house I was renting. I turned the power off at the light switch and went to work. I got the old fixture down without incident, but as I was hanging the bracket for the new one, my hand brushed the hot lead and impolite words came out of my mouth. It turns out the lightswitch interrupted the neutral side, not the hot side. Oops. I posted a thread about this at the time, several years ago. Another time, my father-in-law was sure he cut the power to a switch I was working on. Turned out the breaker box was incorrectly labeled. Got bit there. Ouch. My father-in-law also turned a light on while I had my hands up in the wiring. Ya know, maybe he’s really trying to kill me. 
I do not reomment “touch and swear” as a good method of testing a wire. I bought a $2 tester for that, and now I have this fancy multimeter. I have some electrical outlets to replace at home and I will definately be checking the wiring before I disassemble anything. I do not want to become “Crispy drummer”.
handy’s comment about a 50000 volt Taser is a good example about a little knowledge being dangerous.
The simple answer to the OP is that, yes the electrical power in homes is dangerous and shouldn’t be messed with without extensive and detailed knowledge.
I had some questions relating to this, which I’ve started in another thread, about AFCIs and shared neutrals.
Actually, I realized you might not be talking about a shared neutral circuit, but saying that you were a better ground than the house’s wiring box. Is that the case?
Well since Whuckfistle and others have given their input, I won’t repeat it all. But one thing I can say in regards to the following:
Two things…well, three including hi Opal. First, Doing this assumes that your circuit labeling is correct. You can’t make this assumption unless you’ve done the original wiring. And second, you can seriously damage your eyes like that. When I was a first year apprentice, I was working on a cafe renovation. It was fairly dim in the room (thus more dialated pupils) and I accidentally crossed a couple of wires with the shaft of my screwdriver. :smack: The ensuing flash burned my eyes and was quite painful. Needless to say, that’s where I started taping my screwdriver shafts, and bought a pen tester. It’s made by IDEAL tm
ReBusEniGma, Crafter_Man … anyone else who doesn’t get the screwdriver technique:
The first step is to turn off the circuit. Test it with whatever testers you want. Once you’re absolutely sure the circuit is off, short a screwdriver across the wires. I can’t think of a circumstance where shorting the wires together can fail to detect dangerous current. Testers fail, hot and cold wires can get swapped, and circuit breakers might not be labelled correct, but if huge sparks don’t come off the screwdriver, the circuit is off.
My point is this is the last thing you do before you grab the bare wires. The only safe circuit to work on is one that is not powered, so you better be absolutely sure the circuit is off.
I disagree with this. People are taught to fear electricity, but there’s really no reason why most simple electrical work can’t be performed by homeowners. With a few basic tools and a primer in circuit safety, wiring light fixtures, replacing switches, and installing outlets should be a breeze. It’s only when you start installing new breakers and junction boxes or running new cable that things can get hairy.
Also, touching bare wires to see if they’re live is downright stupid when a simple audible voltage tester costs a mere $10.
I think it’s totally unnecessary to use the “screwdriver” as a final check, but I certainly won’t stop you from doing it. For a reason you stated that, “the tester might fail.” True. And that’s why you should always test the tester on a circuit you know is live beforehand to make sure it works.
Go back and read my post.
I had turned off the power to the circuit I was working on. This eliminated all electricy on the hot side of the circuit. However I got shocked off the neutral side. Now if the neutral wire has some potential (mine did I assure you) and you connect it to a non hot, non grounded wire there will be no sparks. The neutral wire will still have the potential to shock the hell out of you.
Granted. However, using one of my beloved Klein’s (I’m a freak about my tools) as a last insurance, wouldn’t be my approach. Besides, I couldn’t; As previously mentioned, they all have sleeves to the tips. But only as a matter of safety.
Alternately, why not just short each wire to the box then? (I’m using a receptacle box as an example) If there is power still there, it’s gonna pit your driver for sure. I’d rather pit a box that no one ever sees rather than a good screwdriver.
I was working on a hot circuit today. I decided that it would be better to turn off the breaker. After doing that I tested it with my fluke and decided that the circuit was off. Before I touched the bare part of the wire I brushed it purposely against the side of the j-box. I did this as if it was instinct. I dont even realise I do it anymore. My point is, it is the same as taking a screwdriver to the wires except I was using a grounded j-box instead. I didnt bring it up in my earlier posts because I forgot that I even do it.
Having said that, grounding the circuit on purpose even though I know it to be dead is the one last step to assure myself that I won`t get my ass kicked by it. By the way, it was 277volts. Very mean voltage, some say worse than 480volts.
You can get nailed by an open nuetral, as RICK said. This can be worse than getting caught in up in the line side of the circuit.
If you have a three phase 120/208 or 120/240 volt panel and you network three circuits, you could have some nasty (unbalanced) return voltage on that single shared nuetral. It`s like getting hit with three phases at once (not really, but sorta).
Carry on.