No it is not, because if there is no current through the circuit, there is no current through the body. If you become one with the circuit, guess what, those ampers are now running through your body. The intensity of the current is now significantly higher, which rocks your world!
If you tie into an unloaded 120v circuit and you somehow complete the circuit but there is no draw or pull on the circuit because nothing is on it, it'll hurt but your chances of being killed are less than say if your dishwasher and fridge were pulling something. You can dispute this all you want, I tie in all the time with stuff pulling all day, but if I have the opportunity to have less appliances, lights, etc pulling on the circuit I'll make sure they are shut off. You have to understand that in my world, the distribution boxes are outside. In movies we pull from a 1200A generator or 1.5 megawatt generator and our bus bars are outside in the elements on the ground. We cover them in rubber matts and place them on wooden boxes but they get rained on. They are exposed to the elements, your chances of being fried are exponentially higher. When it is raining and we are shooting a movie, guess what, all the electricians on set are wet. Guess what, our resistance makes us prime targets for being great conductors, union linesmen working on powerlines also work in the rain. You may not even know if you are upstream or down stream from the current either.
You have to understand that when I am at work, we have several 18,000w lights on the circuit and much more. It may even be raining. I'm gonna make sure those are off when I tie in because there may be 400+amps on the line when my hands are hooking up camlocks in the rain. If they must stay on, I'll make sure the circuit at my point of the rig is terminated at my point of the rig by breakering down before I tie into my section up stream of the source. If not and I must tie in live, I'm very careful to have my hand only on the one connection, I don't have a knee on the ground, and my other hand is not touching anything else that could ground me. I also make sure that nothing upstream from me is turned on. If my feet are wet I stand on a wooden box. My point being, if you were to make a mistake, which most DIY people who have no experience in the electrical world will ultimately do. They will totally add a breaker or wire with a hand planted on the edge of the box, or the mini fridge next to it, or a hand in a bucket of water, or a knee on the ground. Hell, on a home brew forum they'll probably be three or four deep before they even attempt it.
If some of these guys who have never worked as an electrician but are ****ing around with their breaker boxes in their homes to make cheap beer, shouldn't they take the extra precautions and not get killed? If you can tell me seriously that amperage vs no amperage on a circuit makes no difference, you have no idea what you are talking about.
I understand fully that the principle that "current kills" is essentially correct. It is electric current that burns tissue, freezes muscles, and fibrillates hearts. However, electric current doesn't just occur on its own: there must be voltage available to motivate electrons to flow through a victim. A person's body also presents resistance to current, which must be taken into account. Amperage cannot exist without voltage, and electric shock cannot exist without resistance met.
Taking Ohm's Law for voltage, current, and resistance, and expressing it in terms of current for a given voltage and resistance, we have this equation:
I=E/R
That is elementary. You can't have current without the other. But if you have an accident, which happens, amperage is a factor that can be easily avoided by simply shutting a breaker off. Remove it from the equation. It's one less factor that could result in your premature death. Which is one less thing to worry about regarding SAFETY. SAFETY always trumps everything in the union world of being an electrician. Screw that cowboy ****! I'd much rather be hit with 220v with no amps than 220v with 100amps. Just saying as, I've actually been hit by a 220 run before with a significant amount of amperage. Enough to blow me back 10 feet, make my life flash before my eyes, burn a hole through my left hand, and left foot, and almost made me piss my pants. The final result was 3 days in the hospital and a skin graft. What sucks even more, it was out of my hands. The 4/ot gauge cable had frayed and bad shielding which resulted in my my very near premature death. I've also been hit with a 220v neon light(it was an open ballast that acquired some moisture) which shook me up but I continued work. It didn't burn me and I didn't almost pee my pants, it didn't throw me 10 feet against a wall knocking me unconscious.
You can take chances all you want, but you don't know who hooked up your breaker box. You don't know if there is a frayed wire, a pipe leaking somewhere in the house on the circuit, a moist piece of rotten wood that is grounding out a hot frayed wire, or any other messed up variable that is out of your control. There are so many variables to the situation that my life isn't worth not tripping a breaker off before I tie in. If you feel like trusting an equation that is your business. As a journeyman Electrician in the film business, I'll advise otherwise.
If they trust me to hang 18,000w lights over Daniel Day Lewis's head, I'd trust that I know what I'm talking about. Yes that is right, I worked on Spielberg's Lincoln last year, it is nominated for 12 academy awards. I hate no name drop but you've left me with no choice. I doubt that they'd trust me to do my job if I did not know what I was talking about.
Here is my online resume if you don't believe me.
http://www.imdb.com/name/nm3016550/?ref_=fn_al_nm_1
In the meantime people, be safe, think smart, don't make yourself one with power. If you are scared, hire a professional. I've wasted enough time on this thread, trying to prevent people from getting unnecessarily hurt. If you want to be a cowboy and take a risk, go ahead. But there is more than enough power in your main breakerbox in your home to kill you. If your life isn't that important to you and you have no idea what you are doing, trust the guys advice above me who have yet to say what their credentials are, go ahead! **** the ampers on you circuit, it'll make no difference according to these knuckle heads.
I for one would much rather be shocked at 220v with no load than 220v with significant ampers. I've been hit with both. One resulted in a slight sensation and the other blew me back 10 feet. You be the judge, it's your life.
