Ceiling mounted PIR's how easy to fit retrospectively?

[oharaf]

Have been to look at a job which includes fitting PIR's to ceiling on each of 3 floors.

The fitting schematic provided indictes that it requires L, N, E (which would come from the ceiling rose?)

There is then a 'link' from live across to live. It then says to connect L1 (OUT) to this.

Q. Am correct about bring a feed from the ceiling rose?

A diagram would be much appreciated I just cannot visualise what would occur

 

[Pensdown]

A PIR occupancy sensor is wired from the ceiling rose just like a 1gang 1way light switch. It has a common & switched live. The only difference is the PIR requires a neutral

 

[oharaf]

Thanks Pens

What I am struggling to visualise is how I 'add' this in to the current circuit.

Do the wall switches become null and void? Or am i missing something?

I can see very clearly that without a switch it is very simple to connect, but

surely manual operation is also required

I'm just failing to see it

 

[Pensdown]

A conventional occupancy sensor normally replaces a light switch. If you want manual over-ride on and off you'll be better off installing a more intelligent occupancy sensor. The down side is they can be quite expensive and they often require other controls.

For your application, would you want to over-ride both off & on or just one way ?

 

[oharaf]

Would have to check, but overide to on. It is more important that the sensors are in place and working for the old and infirm that move across all three floors!!!!

TBH i don't think the customer would fuss about overide as he was accepting that switches would need to be blanked off!

 

[slup]

What about just replacing the switches with these?

 

[Pensdown]

The Danlers WAPIR works very well. The down side is the over-ride off is a latching push button. So if someone does over-ride off, the automatic PIR operation will remain disabled until someone turns it back on.

 

[oharaf]

Looked at these, the problem is their switches are in strange situ, the light needs to come on as soon as the old dear appears on her Stana stairlift, so ceiling PIR more suited.

Like those mind, if they were tad cheaper then I might fit our house with them