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Discuss internal house hallway, 2 way lighting, customer wants to retain 2 way light switches but add aPIR in the Electrical Forum area at ElectriciansForums.net

john forrester

New EF Member
Hi Guys, customer's house hall has 2 way light switched circuit, I have been asked to add a separate PIR to the existing light circuit to allow the lights to come on when PIR is activated, he wants to retain the existing 2 way switches as overall on/ off control when required independent of the PIR, I have wired in a PIR, which works OK< but cannot get the switches to keep lights on when required, HELP...


Forum Mentor
Welcome to the forum mate.
So what you are doing is changing the light switch into a 3 way intermediate switched light.


You will need a PIR to have a change-over switch and change one of the light switches into an intermediate switch.


Electrician's Arms
If you need the light switches to retain their existing function then perhaps add the detector "over the top" so it provides another switched live to the lamp? Then they'll only want the it to work at night so you'll need luminance detector and only if I want it so you'll need another switch to take it out of circuit as well :rolleyes: .
Last edited:


Regular EF Member
When I’ve done this before I’ve used two switches at the end of the two way where the switched live for the light has come from, with a 3 core cable going to the PIR. One switch operates as an over-ride to the PIR and effectively takes the place of the “normal” light switch. The additional switch switches the supply live to the PIR. With this set up the 2 way can be “off” but the PIR will switch the light on anyway (depending on the set up of the PIR), or the PIR can be disabled and the 2 way work as normal.

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