110 is probably better in terms of general safety
Eh, not really. There is no significant difference in safety between 110vac and 230vac. Voltage is not the (most) dangerous part, it’s the amps that kill if you’re electrocuted.
Comment on Prototype of RTX 5090 Appears With Four 16-Pin Power Connectors, Capable of Delivering 2,400W
InverseParallax@lemmy.world 4 weeks agoActually, in the US the outlets are often wired with 1 leg, while giving 2 legs gets you back to 240v.
110 is probably better in terms of general safety (which is good because our houses are death traps), but it means when you do need power you need a special circuit.
We should have both more common, but the plugs are terrible (basically they turn the left prong 90 deg).
ExcessShiv@lemmy.dbzer0.com 4 weeks ago
InverseParallax@lemmy.world 4 weeks ago
Amps are voltage over resistance (I = V/R), volts absolutely matter, the human body has a decent resistance and the higher voltage helps burn through that.
ExcessShiv@lemmy.dbzer0.com 4 weeks ago
There’s a reason we talk about lethal current and not lethal voltage…30mA can kill you, even at something ridiculously low as 9V, but 5-10kV will not necessarily kill you, e.g. fences for horses will not kill you if you’re electrocuted by them because there’s basically no amperage. Voltage is not the determining factor in lethalness.
mriguy@lemmy.world 4 weeks ago
In most household shocks, you touch a conductor, and you are the resistor to ground. Your resistance is independent of the drive voltage, so if you touch a 110V wire, the current will be half of what you get with a 220V wire. So the voltage determines the current, and this the lethality.
There’s lots of other factors that go into the effective resistance like the amount of moisture on your skin, what shoes you’re wearing, and what the floor is made of, etc, but in all cases twice as much voltage will cause twice as much current.
It’s a bad idea either to go touching live wires either way, but the rule of thumb I heard was was that a 110V shock usually won’t kill you and 220V shock usually will.
InverseParallax@lemmy.world 4 weeks ago
There is no current without voltage, what you’re saying makes no sense.
Current is voltage over resistance, you get as much current as you have voltage, unless there’s an artificial effect limiting voltage, like a voltage regulator or zener diode or just fet.
When you say ‘it’s the current’, that electric fense has x volts before you touch it, and the fact that it doesn’t kill you means either the voltage is too low to produce a decent current in your body, or, there’s a voltage regulator/limiter that means when you touch it the voltage drops to some lower level, which I could calculate using the nominal resistance of the human body and the voltage of the fence.
In a way, the output impedance of whatever is driving the fence determines how much the voltage drops under load.
justJanne@startrek.website 4 weeks ago
We also have a standard socket and a high power socket.
Expect our normal outlets provide 230V 16A 3.5kW (3kW sustained) and the typical high power outlets outlets provide 400V 30A 11kW or 400V 60A 21kW.
Which is why typical electric stoves here use 11kW and typical instant water heaters use 21kW.
Though probably the most noticeable advantage is in electric car charging.
InverseParallax@lemmy.world 4 weeks ago
Yeah, in Sweden I charge our plug in hybrid off 240, it’s pretty quick and you can use any outlet.
The giant round connectors are weird BTW, with all the holes, trying to sort that out for faster charging.
I don’t think we should run 100+ volts everywhere, we need to standardize on lvdc in most places (basically usb-c or so) with 100v only in kitchens and places you need it, because it’s more dangerous and can cause fires more easily.
justJanne@startrek.website 4 weeks ago
That’s a common misconception. It’s the Amps that cause fires, not the voltage.
The 5090 uses 600W, at 12V that’s 50A, but at 120V that’d only be 5A and at 240V only 2.5A.
50A melts cables and burns your PC down, 2.5A won’t. The only risk of higher voltages is that they can jump across small air gaps much easier.
InverseParallax@lemmy.world 4 weeks ago
No it’s not, I’m an ee.
P = I^2R, so power doubles with the current, while it’s linear to voltage.
This means current causes more heat dissipation in the wire, which has risks, potentially fire if you really go too far, this is why breakers trip.
But what really causes fires (again, outside of crazy overcurrent) is Arcing, from basically either bad connections or bad insulation, OR, from an inductive load that gets disconnected, so the current tries to stay constant in the coils, which leads to massive voltage spikes.