Why do circuit breakers go up for on and down for off?

No it isn't. You push it the way you think off is. I'd push up, since most things are up for off. First one that springs to mind - the cooker switch on my kitchen wall, along with the socket next to it, in fact every single socket in the house!

Probably because that's two rows. And it was easier to wire them together at one end instead of having great big cables going right across.

I wonder what happens if you put your finger in that gap with the terminals stuck out?

What's the link to the reddit discussion?

I used to have a problem with random tripping of the whole house RCD.

Then I fixed the earth<->neutral short in the workshop and apart from an electrocuted mouse, it hasn't tripped since.

Earth and neutral are the same thing. Only two wires enter my house from the substation.

Some go up, some go down, some go sideways. My panel has all three ! You need to get out more. John T.

I helped to set up an electricity museum.

Not here. They are random.

That's because logarithmic potentiometers are used, and the manufacturers make them in one direction only.

It would be a mess manufacturing both directions. But reverse screws do exist.

Depends on the country.

Here all houses have mandatorily a whole house RCD. Since many years.

I once worked in one - in Niagara Falls - but it wasn't referred-to as a museum at the time - it was still a functioning 25 Hz. power plant .. :-) I often wish that I had taken some photos ... John T.

No shorts found on ours, it was simply too many computers and peripherals, with filters that constantly leak to earth, meaning that it was always high enough that it would take very little to raise it over the trip level and something coming on automatically might be just enough of a change to do it. It was infrequent (once every couple of months), but annoying (waking up late because the alarm had not gone off or losing a freezer load of food because we were away for a few days when it tripped - we lost two lots that way).

Mine goes sideways. Why's that?

But I don't live in America where they have plus 120 volts, minus 120 volts, 240 volts, and how do you remember which live wire is which?

Actually it depends which way you installed them. But I seldom see one which is up for on, apart from two way switches which can end up either way.

And they picked the correct direction.

And they chose the correct one.

They shouldn't.

I see no reason to have two wires at the same voltage.

And if you don't have one you what? Go to jail?

An alarm with no batteries, ROTFPMSL!

And didn't think to remove the stupid thing causing the fault?

Lack of space where your fusebox was installed?

It matches the master switch, which is always up for on (presumably that would have been a knife switch originally).

Up for on in the US. And side to side in Japan - something to do with earthquakes

Steering column stalks can be confusing, especially which side the horn is - I rarely use it, and if I do, I'm in a hurry. Squirting water on the windscreen isn't as effective in alerting other drivers.