3 Way Switch Wiring

[aturner]

Hi,
I want to wire a motion detector switch into my garage; I'm the only one that switches the lights off! The present arrangement is two 3 way switches powering two fluorescent tubes. I'm happy to take one of the three way switches out of the equation but am having some difficulty in identifying which cable is which. I've posted the pictures of the two switches and wonder if anyone could help. I'm pretty safe with electrics and have a multimeter. Any help greatly appreciated.

AT
[/img

Untitled

• aturner
• 20 Nov 2008
• 2

]

 

[jj4091]

Please do not take this the wrong way, but I do not see how you can be "pretty safe with electrics" when you do not recognise a 2-way switch, please, call someone in

 

[mikeyd]

Its in the wiki here: //www.diynot.com/wiki/electrics:lighting:two_way_lighting:chocknonharm

But why do you need to alter the switches? You can't just replace one or both with a PIR because it will need a neutral. And you still need at least one switch.

 

[Taylortwocities]

I do not think i have seen a PIR that provides two way switching so, yes, you'll have to lose one of the switches.

Make sure the PIR you get is OK for fluorescent loads.

 

[Spark123]

Not entirely sure a 2 way PIR would me much use
Can wire it so the PIR runs the lighting and do away with the switches (bar one for maintenance purposes) - becoming quite a common arrangement in offices.

 

[aturner]

Hi all,
Thanks for all the advice; I think most of you gathered I should have said 2 two way switches, but several articles in this forum refer to the combined effect as a 3 way circuit. I think the way to go is as suggested: to replace one switch with the pir and leave the other in parellel for maintenance. Again many thanks.
AT

 

[Spark123]

Will need to be in series for maintenance i.e. so you can switch off to replace a lamp.

 

[mikeyd]

As stated above your PIR will need a neutral so you are going to be running in a new cable anyway. You could keep both switches and wire up a PIR (with a new 3 core+earth to the light fitting) to work in series with the switched live. Hope you don't use the garage as a workshop though. Wouldn't want to be under a car with a grinder when the lights time out.

 

[aturner]

Thanks mickeyd, good advice. Also the earlier link was just what I needed, great diagram that explained it all.

 

[ban-all-sheds]

Please do not take this the wrong way, but I do not see how you can be "pretty safe with electrics" when you do not recognise a 2-way switch

He could have been from the USA, living over here...