The shock was very painful but the RCD tripped and saved my life. I'm quite grateful to the regulators here in Australia that made them mandatory back int he 90s.
I've been shocked by 110v countless times (well, maybe a dozen or so), and it's just an momentary shock (in both senses) and nothing more. Not recommended! Be careful! Circumstances (water) can make it fatal! But still I've been fine.
Australia and lots of other countries use ~240v as normal household voltage. I've never been shocked by 240v, but from your description I'm really glad about that.
Are there any downsides for using 110v instead of 220v?
> Are there any downsides for using 110v instead of 220v?
You need thicker wires and higher current to carry the same power. In Europe electric kettles are much more common because they can use up to 2kW in most households without any problems.
This is not really correct. Voltage is potential difference, so the voltage of a single conductor as measured from a single point is always zero, as there's no difference. Similar to how a boulder on top of a hill on Earth has potential energy from gravity, because there's a difference in height, and a force acting on that mass. That same boulder with no hill or gravity has no potential energy.
In America, residential panels are generally wired with three current carrying conductors (hot, hot, neutral), and a ground. Each hot is one leg of a 240V transformer, and the neutral is a center tap, which has 120V of potential difference (voltage) between both hots. In 120V circuits, one hot is combined with the neutral for 120V of potential. Other circuits and outlets can combine two hots for 240V of potential, or two hots and a neutral for both 240V and 120V capability, such as might be used by your dryer, with large motors and heaters driven by the higher voltage, and control circuitry being powered by the lower voltage.
> Are there any downsides for using 110v instead of 220v?
Because the current required for the same amount of power at a lower voltage is higher (Ohm's law), thicker wire is required to carry that current, and more heat is generated.
Source: DIYer who's wired my own garage, including a 100A subpanel and various circuits, which was all permitted and passed inspection.
> Are there any downsides for using 110v instead of 220v?
Not really, except that most appliances will only use 110v instead of 220v, because most power outlets are 110v with a few special 220v outlets set up specifically for heavier appliances. Usually 110v is perfectly adequate anyway, but electric kettles in America are slower.
Luckily, electricity is about 20x safer as long as it is supplied for less time than one heartbeat[1] - ie. 500 milliseconds.
Thats how RCD's can be so lifesaving even though they are relatively slow.
[1]: https://en.wikipedia.org/wiki/Electrical_injury#/media/File:...
Imagine you had an ideal switch that could disconnect a circuit instantly.
Any devices powered on that circuit with transformers, inductors or motors in (think vacuum cleaners, power tools, microwaves, blenders, etc) will have a current flowing through them, and as that current is interrupted there will be a huge voltage spike - easily 10x the normal voltage for a few milliseconds.
If a human is touching that circuit, the 10x higher voltage will cause 10x more current to flow into the human.
Hooray - your 'safer' RCD kills more people.
The real solution is to have a more complex switch which disconnects the circuit at the same time as shorting out the circuit, to allow any current that was flowing to gradually dissipate into the wiring resistance. To my knowledge, such things don't exist today.
Luckily, the problem I described is almost a non-issue. Deaths due to electrocution in buildings with a GFCI have fallen to pretty much zero - there were only four deaths due to electrocution at home in the UK last year (where voltage is very high and RCD's are common). That figure includes deaths by suicide, lightning indoors, and deaths where an RCD wouldn't help such as poking around inside CRT's, so it's entirely possible an RCD is already saving every life.
Now divide 1000ms to 50Hz.
@londons_explore pretty summed it up and gave a link to a very good graph.