3-way hall light into pir either end!

aidge · Sep 23, 2013

I have a client who needs his hallway light to come on automatically from the front door and basement areas but switch manually from his hallway. It is currently 3-way switching with no neutrals at the swtches. His existing hallway switch is the intermediate switch. Can anybody help me with solutions to this little 3-way conundrum?

Tiny Spark · Sep 23, 2013

Never had a huge amount to do with PIR's but the control units I have come accross are SELV ones and have the ability to use a over ride switch.

Basically you give the controller a 240V supply and it has a relay built in that you put your switch wires through.
But the sensors and switch is just SELV.

They also had a built in timer so the lights would turn of after X minutes if no activity was detected.

Paul.M · Sep 23, 2013

What you need is two "live only" pir's that are two way and wire up as normal with the ind in the middle.

I did the same set up a few years ago in a nightclub stairway and it was a pig of a job to work it out.

i=p/u · Sep 23, 2013

I've seen ones where you swap the switch for pir with no neutral, don't know if they two way tho

Paul.M · Sep 23, 2013

i=p/u said:
I've seen ones where you swap the switch for pir with no neutral, don't know if they two way tho

Yes they do. Just replace the 2 way switches for these and keep the ind in place and wire as normal.

Ps good luck with the testing......... link out one switch wire at a time to get your r1 r2.

tazz · Sep 23, 2013

if 3 ways light has been installed, then there should be 3 core + E running from on switch through the intermeadiate to the other. Happy days used one core as the neutral, as you dont require strappers now for pir switching

westmac · Sep 23, 2013

Paul.M said:
What you need is two "live only" pir's that are two way and wire up as normal with the ind in the middle.

I did the same set up a few years ago in a nightclub stairway and it was a pig of a job to work it out.

This would throw up some strange behaviour though, if one turned the light on then the other would turn it off if someone walked near the other.

The requirements for control depend on how you want the switches to behave, should they be able to switch the lights on permanently or should they go off after a certain time once the switches are operated?

Rockingit · Sep 23, 2013

Assuming that what you want to achieve is the light to come on when either PIR is activated, plus a manual on/off, the simplest solution I can think of would be to use 2 cores of your 3c as perm L&N to each PIR, and use the 3rd core as a switch line back to a contactor, both PIR S/L's to activate the coil along with an ordinary 1G lighting switch to do the same. That way, the PIR's work in the normal way separate to each other and the manual switch is self explanatory.

I guess you COULD get inventive with a latching network if you wanted to over-ride the manual switch when the PIR's dropped, but that gets a bit messy. Or you could always buy a cheap and cheerful PLC and write some code........

ipf · Sep 23, 2013

I've got one to sort out on an old 3 story block of flats . Seems it's never been wired correctly since alteration a while ago. Obviously intermediate originally. Could be a pain.
Pressure time switch on ground floor, with two pir beams on 1st and 2nd floor. Not had time to look into it properly but checked the pressure switch, which does nothing, 3 wires, altered to 2 terms used....all live whether the lights are on or off. I'll get back when I've got some time....and someone to give me a lift running up and down the stairs.

Richard Burns · Sep 24, 2013

If you use 2 wire PIR switches at either end and wire them in parallel with each other and also in parallel with a one way switch in the hall (to replace the intermediate) then if either PIR operates or if the hall switch is turned on then the lights will be on, if the hall switch is turned off then if the PIRs are still active the lights will be on until the PIRs switch off. You would need to label the hall switch off and on so people would know.
You would have one redundant core (assuming it is wired as three wire) and so if you were able to get a neutral to any of the light switch locations you could use that third core as a neutral to save having to have 2 wire PIRs

[ElectriciansForums.net] 3-way hall light into pir either end!

tazz · Sep 24, 2013

Richard Burns said:
If you use 2 wire PIR switches at either end and wire them in parallel with each other and also in parallel with a one way switch in the hall (to replace the intermediate) then if either PIR operates or if the hall switch is turned on then the lights will be on, if the hall switch is turned off then if the PIRs are still active the lights will be on until the PIRs switch off. You would need to label the hall switch off and on so people would know.
You would have one redundant core (assuming it is wired as three wire) and so if you were able to get a neutral to any of the light switch locations you could use that third core as a neutral to save having to have 2 wire PIRs

View attachment 20707

By jove....somebodies got it

telectrix · Sep 24, 2013

nice clear pic. well worth a thanks.

adamh · Sep 26, 2013

Only glanced at this but I thought I would throw my 2 pence in ...
he will still have to get a neutral to 1 of the switch positions and also fit a timed switch or the pirs suggested earlier and a pneumatic switch

tazz · Sep 27, 2013

adamh said:
Only glanced at this but I thought I would throw my 2 pence in ...
he will still have to get a neutral to 1 of the switch positions and also fit a timed switch or the pirs suggested earlier and a pneumatic switch

A member goes to the trouble of explaining fully and drawing a full circuit diagram, and you post this.....?????