Light switch wiring

[leenowell]

Hi All,

I am wiring up an MK outside light switch. The switch itself is a 2 way switch but I only need one way. I tested it with my multi meter and it wasn't working. After a bit of trouble shooting, it transpires that with the switch up what would appear to be the right way (the writing on the back is the right way up), when the switch is off I get continuity between com and the '1 way' terminal and no continuity between com and '2 way'. When I turn the switch on I get the opposite result. This would imply I should connect across com and '2 way ' for a 1 way switch ?

Same is true for the second switch I have.

I suspect I am being dozy here. Any thoughts.

Many thanks

Lee.

[charles]

It all depends on how you want the switch configured. To some people Up is ON to others - the opposite. So Com to whichever suits you.

[Mike Humphrey]

A 2-way switch doesn't have "off" and "on" - it effectively has two different kinds of "on". You need to connect "COM" and either of the other terminals. If this makes the switch work "backwards" from what you want, either turn the switch the other way up or use the other terminal (but not both, as that puts you back where you started). I wouldn't assume the writing on the back is significant - I've had accessories that can clearly only go one way up where that puts the writing upside-down, or even sideways.

Mike

[Max Demian]

"Some" = Americans. "Others" = British.

(If you are expecting it to be used by Japanese, you will have to mount the switch sideways.)

[charles]

the circuit breakers in my CU are UP for on and with 2 way light switching, you never know.

[Max Demian]

Well that's just because of how they work.

Circuit breakers (and the main power switch) are Up for on, but I guess they are Different.

I think the US convention dates from when they used exposed knife switches, so gravity would turn them off.

[John Rumm]

Yup - 2 way switches have a "changeover" action (or Single Pole Double Throw if you prefer)

(you could use the com and 2 way terminals, and just invert the switch. Many 1 way switches have space for the three terminals even if one is not actually fitted)

Here is how they work in different applications:

[leenowell]

Thanks very much John