On Sunday, 4 November 2018 03:58:17 UTC, Ralph Mowery wrote:
In article ,
tabbypurr says...

It makes a huge difference.
Fuse in live blown: faulty equipment is now dead.
Fuse in neutral blown: faulty equipment looks dead but is live.
One can electrocute you after a live to case fault, the other won't.
This is why UK banned dual pole mains fusing in 1955.




Ideas and codes change from one country to the next and sometimes even
in the same country.

In my opinion one of the worst things was some equipment where aI
worked. The standard in the US was that on electrical equipment boxes
red was off and green was on. We got in some equipment from Europe and
they used Green for off and Red for on. The reason being that Green was
safe to open the door and red ment power was on and danger.


I know that in a series circuit that electrically it does not matter in
which order things are for them to work. I was just courious that much
of the older two wire 120 volt stuff that has a transformer , the power
comes in, then a switch, transformer primary , fuse and back out to the
power. I would have thought it would be the power, fuse, switch,
transformer and back out to power.

The only justification I can think of for the old practice of putting the switch & fuse in different leads for unpolarised kit is the idea that the switch is a relative weakpoint, so would likely act as a higher current fuse if there were a short from live to some good earth - not good but better than nothing. I suppose it's also marginally easier for production to have 2 things to solder the mains wires to.


NT