replace pull cord with sensor needs live feed?

[katypoo]

i have bought a surface mounted motion sensor to replace my pull cord switch in the cloakroom (not bathroom). problem is with the wiring.

I removed the old pull cord switch and it has one 3 core cable (red, brown, earth) connected to it.

looking at the pir wiring instructions, i need an AC power source to power the sensor. I can access the other cabling in the ceiling so what can i do to get working.

I don't want to buy another sensor that does not need the neutral!

many thanks

 

[EFLImpudence]

You will need to replace the cable from the light to the switch (assuming it is wired conventionally) with 3 core and earth so that you can connect the neutral.

 

[katypoo]

You will need to replace the cable from the light to the switch (assuming it is wired conventionally) with 3 core and earth so that you can connect the neutral.

Thanks - sounds easy! i have a junction box which is wired to the old switch and onto the lights plus it feeds other lights. a mass 2 core cables with earth. no other 3 core + earth so does this mean its not possible?

i am unsure what to connect a new 3 core + earth cable from the switch to?

 

[Aragorn84]

you would replace the existing cable between the junction box and switch with the 3core+earth, replicating the existing three connections, and use the additional core to supply the switch with its neutral, which can be found at the junction box.

 

[ban-all-sheds]

But don't throw away the switch.

You'll be wanting to put it back when you can't stand having the PIR in there a moment longer.

 

[Taylortwocities]

But don't throw away the switch.

You'll be wanting to put it back when you can't stand having the PIR in there a moment longer.

I agree.

Imagine

The PIR/sensor is set of 5 minutes. You settle down and open up your copy of 50 Shades of Grey. Then the light goes out.
You leap up from the WC so the light goes on again, you turn back to page 78, just when you get to the interesting bit, the light goes out again.

 

[sparkiemike]

I have an occupancy sensors in my office and in the kitchen. Had them for over two years now.

My wife loves them, because when she walks into the kitchen with her arms full of shopping the lights come on, and I don't get nagged when I forget to switch off the lights in the office. There are override switches but we hardly ever use them. They work in my house.

I also fitted an occupancy sensor in a bathroom for a client, so that when he comes into the toilet at night the light comes on dimmed - just enough to see and pee, but there is also a overide switch for normal operation - i.e. all lights on with full brightness, he is also very happy with the arrangement.

They can be used sucessfully in a domestic setting.

 

[katypoo]

i deliberately bought a sensor that stays lit for up to 40 mins - more than enough for my other half to do his business and read private eye! have led lights now so 40 mins is not a problem. the old pull cord made quite a noise and wakes me up in the night!

 

[flameport]

No doubt these sensors can be used in a domestic setting, but the cost of the sensor and installation will far exceed any savings made from the light being switched off automatically.
At 40 minutes, in some houses the light would be on most of the time anyway.

As for pull cords making too much noise - yet more people who apparently don't flush their toilets.

The real answer to pull cord noise is to fit a normal light switch on the wall. Including in the bathroom.

 

[securespark]

I must say that I have used a PIR in my bathroom, but only to trigger the in-line duct fan.

So the fan will be triggerable 24/7, and not dependent on the light.

 

[sparkwright]

I bet it's not a cloakroom at all.

I bet it's a downstairs toilet.