Edit: great approach to understand the matter: https://youtu.be/BGD-oSwJv3E?is=Fe1FimqTCvN-aY1u
I was looking at some transformers:
But also
If it outputs 12VA (12V * 1A) of apparent power, then it receives/works with (?) 12VA apparent power. That means that the current in my 230V wall outlet is 12 / 230 ≈ 0.05A. Even a button cell can supply 0.15A per hour… This leads my uninitiated head to believe, that it is mainly high voltages that are not compatible with life.
Please advise? 🙃
It’s 100% current, but the current that matters is the current through you. The resistance between your hands is roughly 3 kΩ at low voltages and about 1 kΩ at 220V. You need about 5 mA DC or 1 mA AC to feel anything, which means you need about 15V DC if you’re the only resistance in the circuit.
The current at your outlet will be ~0.05A if the only path between hot and neutral is the transformer. If you add an alternate path, you allow for up to 25A or so before the breaker cuts the circuit. 25A would mean that the resistance between hot and neutral is about 8Ω. If you are the alternate path, there will be about 220V/1k=220mA going through you, which is about 8x the amount needed to cause you to go into cardiac arrest.
The only time that the current in the outlet while the transformer is connected would matter is if you were in series with the transformer. If you stuck a wire into each side of the outlet and connected one to one side of the transformer, then grabbed the other wire with one hand and the other side of the transformer with the other hand, you’d experience a shock of about 55 mA (0.05 A, like you calculated), which would still probably kill you.
The button cell doesn’t do anything because it’s 1.2V. That means its max current through your body is about 0.4 mA, or 0.0004A. It’s also DC, which means that it affects your body about 5x less than the AC in your wall outlet.
Nope. Circuit breakers do not break on absolute current values. Ever. Period. At all. Even a basic spec sheet will inform you as much…
It’s why many euro firms make fun of American standards: They’re literally not expressive of reality.
Even GFCI’s can shock the fuck out of you in certain circumstances.
Huh, TIL.
That doesn’t seem to be supported by my research. Standard breakers are designed to trip based on a function of over-current and time, but that doesn’t preclude any breakers from using current alone.
It won’t. I checked. A more detailed spec sheet will, but not a basic one.
They sure look like they are. The rating is the current that the breaker can sustain indefinitely at the reference temperature. And it sure looks like the EU rates them the same way.
Of course they can. You aren’t a ground fault. A load of 100mA on a GFCI is perfectly normal, and the same load will kill a human very quickly.
If you cannot understand the BASIC fact that a circuit breaker can ABSOLUTELY conduct more energy than its rating before it pops… then you are simply too stupid to understand what I said. Period. Absolutely. Good job being so dim.
They look like they are … to an ignorant incapable of reading comprehension. Which is one reason why the standards are made fun of.
Care to explain your reasoning, then? Or did you just want to feel smug?
Edit: boy howdy, looks like you’re completely wrong anyway. While the breakers certainly don’t trip at their exact ratings (good thing I never said that they did) and do take time to trip for certain loads above their ratings, there is an absolute cutoff, somewhere between 2x and 20x their rating depending on the breaker type. So my number was a bit off, should have been 30-500A depending on the breaker type and rating, but it was a lot closer than “never ever at all.”
Your whole comment was great but this part in particular cleared up things really well for me:
I was a little worried that that part would distract from the overall message, so I’m glad I ended up leaving it in and I appreciate you telling me that it helped.