PIR Help

[steviez]

Hi,

Can two PIR sensors (the out door ones) be wired so that any of them would turn on a light? I have a passage between my house and i need the light to be activated either at the top of the passage or the bottom.

Thanks

 

[martinxxxxxx]

Some can

You need to check that they are "2-way" switching before you get them or wire them in parrallal which is a bit more to get you head round

Actually looking further into it I am incorrect about 2 way but no reason you can't use two in parallel.

The Spectra allows for an "override" - i.e. between L and L1 to be bridged for a period of time to allow the controlled lighting to remain on.

So the way you'd do it is simply to take both L1 terminals to the light fitting, making sure you've got a common neutral and Live feed to both PIRs, and a common neutral on the light fitting.

If you want override, then you can use a one way switch to either PIR across L and L1, and if you want a permanent off, then use a one way switch in the feed before either L.

I'd probably run a 2+E to the first PIR, then from there in 3+E to the second PIR, then 2+E to the light fitting.

Common the earth all the way through.

So at PIR 1 you'd have:

L = Brown 2+E <--Feed
L= Brown 3+E
L1 = Black (Sleeved Brown) 3+E
N= Blue 2+E <-- Feed
N= Grey (Sleeved Blue) 3+E

At PIR 2 you'd have

L = Brown 3+E
L1 = Black (Sleeved Brown) 3+E
L1 = Brown 2+E -->to light fitting
N = Grey (Sleeved Blue) 3+E
N= Blue --> To light Fitting

 

[bernardgreen]

Most can.

They are simply a switch between Live and Switched Live that closes when motion is detected.

So connect from PIR 1 to PIR " Live to Live., Switched Live to Switched Live and Neutral to Neutral and then treat one of them as a single unit when connecting supply Live and Neutral and lamp(s) cables.

It is very important ensure live and neutral are not crossed between PIRs other wise there will be a dead short across Live and Neutral if both operate at the same time.

That said some with solid state switches may not work as expected if there is a long run of cable between them ( solid state do not click when the lamp turns on ).

 

[1550]

And you need to ensure that the sum of the two lamps do not exceed the rating of either unit .IE do'nt sum 1000w on a 500w pir.

 

[ebee]

It's often done - a call to the manufacturer will confirm that they are happy with this.

Friedland Spectra are OK for this.
As said just watch total load does not exceed max allowed on the units, again the manufacturer will help.