There are typically 3 things when connecting a device to power:
1. wall outlet
2. extension cord/phone charger
3. device being charged or powered
Each has watts/volts/amps labeled. With W/V/A, how do I determine if a system is safe or unsafe?
In: Physics
What makes these circuits safe is if they are properly wired, insulted, grounded, and protected. No loose outlets, no loose face plates, no loose connections, no frayed insulation, no exposed wires, no ground plugs cut off or subverted. Circuits near water should be part of a GFCI. Plugs should be shielded from water and devices no rated to be used with or near water should not be done so.
Regarding volts and amps, what makes them safe is if their circuits are compliant with code and operation – what makes them safe is that you don’t make yourself a part of the circuit. You’ve got guys who work on high tension wires from helicopters, or walk them, while they’re energized, and those things carry currents that simply boggle the minds of electrical engineers – many, many orders of magnitude more power than what they use in an electric chair, and those electricians are generally safe.
It only takes a few millivolts, a few milliamps across your heart to put it into atithmeia and kill you – some household batteries can do that, but that’s the trick, isn’t it? For do-it-yourselfers, they teach you to work on electric circuits with one hand, so that you don’t make a path across your arms, past your heart. I’ve been shocked by 120v 20A by accident, and it’s not pleasant. It’s no joke, that’s way more than necessary to kill you, but since the circuit was local only to my hand, it was just a bad experience I wouldn’t recommend to anybody.
For the most part, we as a society agree that properly used home electric and connectors are safe for the naive public, and home wiring can be learned without any certification. Beyond that – if you don’t know, if you’re not sure, it’s not safe FOR YOU.
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