On 22/01/2019 12:43, Steve Walker wrote:
On 22/01/2019 10:41, alan_m wrote:
On 22/01/2019 08:55, Jim GM4DHJ ... wrote:
do you think the merrycan way of switching with down off is more
sensibubble
that what we do in the uk ?




Two way switching uses both conventions.

Up/down os probably only really seen with older tooggle knobs on
switches. Most of us probably use sockets/switches where pressing the
lower part is on and pressing the upper part is off.

I once worked on a rack of equipment where the (military) customer
specified that a big red illuminated front panel light meant the power
to the electronics was off! Guess how much damage was caused to plug
in boards that didn't like to be hot plugged?

I have worked on designs for many oil and gas/chemicals companies. Most
have wanted a green light for say a pump running ok and red for stopped
or failed, but some wanted the reverse, as they reasoned red for
energised and green for deenergised and therefore safer. A few even
wanted a mix, with green being for fail-closed valves that were in the
open position and for fail-open valves in the closed position, thus
showing their energisation rather than their positions.

A green traffic signal should mean stop as green is a calm colour. Red
is fierce and should mean go.

Green chillies tend to be hotter than red ones, so the hot tap should be
green and the cold one red.

--
Max Demian