Electrical Help Please.

[needawin]

I have an existing external security light. Non pir.
I am going to connect a pir sensor to the circuit.
The mains supply to the light and the sensor will have to go in different directions. What is the way to wire it?

Will I need a feed to the sensor and then a second wire going back from it to the light or is there some way I can split?

[Old_Geezer]

The sensor is likely to need to be wired in series with the lamp as it effectively switches the lamp on and off. I've not come across a more complex version that merely sends a control signal. You'll need to run a cable between the two such that the lamp isn't powered until the sensor allows current to pass.

[bhg481]

The PIR is simply a switch which needs to be in series with the security light, so just wire it as you would a switch. Leave the original switch in place and insert the PIR between it and the light - you will need a juction box.

[Zacs-Master]

Why don't you just buy a new floodlight with a sensor. I got an LED one from Homebase for £14 3 years ago. Not worth the hassle.

[donny48]

An excellent video explaining the wiring for a pir, there are other wiring explanations on thee video but the pir section starts at 14.14, but watch it all through it's excellent.

[donny48]

Forgot the link

[Old_Geezer]

I found one reason not to buy a lamp with inclusive sensor is that at least some are not as adjustable as a separate sensor is. I was effectively forced to change to a sensor controlled lamp some while ago when my local authority reneged on its duty to provide the late night street lighting we pay for via our domestic rates. I now have a lamp that turns on when a car drives by on the street; and I can not move the sensor.

[donny48]

OG, You have just quoted the exact reason I was "volunteered" by my wife to change and re-wire my neighbours light. I was able to change the wiring inside the light to exclude the in-built sensor so all they had to buy was a new switch.

[donny48]

Sorry should have said new pir switch.

[Old_Geezer]

That was very thoughtful of her :-)

[donny48]

Glad she did, when I got there the neighbour was assuming that if you turn off a light switch then you have also switched off power going to the light connection.

[Khandro]

Electrical Help Please....part II (perhaps and if I may)

The old door bell, which was the only original thing that remained after we completely re-furbished our house, was very loud and could be heard on all three floors, it recently packed up and we had a new modern one fitted, but it isn't as loud, and callers are frequently missed (my hearing is also getting worse).

Running extension wires through the house would be difficult, would it be possible to add some kind of sender unit to the bell which operated other bell(s) in a different part of the house by a radio signal, please?

[donny48]

Yes, very easily done use the link below to see examples there are lots of other makers.
http://doorchimesuk.co.uk/catalog/index.php?cPath=42

[Old_Geezer]

You can get radio connected doorbells with the option of further bells/speakers/whatever to put elsewhere. But it sounds as if you have already replaced the system. It may be possible to wire further buzzers/whatever in series but it would depend on the actual ability of the system you have. It may not be able to provide sufficient power for more loads.

[Khandro]

OG; the wiring to the bell from the front door is OK, I'm just wondering if the electric signal to the bell, at the bell, could be used to send a radio signal to other parts of the house, thereby avoiding wiring.

[Khandro]

Ah, just seen your link Donny, that looks the ticket, thanks

[Old_Geezer]

I think you need to Google the one you bought and see if the manufacturers sell such extensions, and if so the distance they should be detectable. In principle it should be possible but the extensions need to be monitoring the frequency that the doorbell transmits.

[beso]

Having to ask this question is a sure indication that you should not being doing this work.

[donny48]

It is impossible to say 100% without seeing the present layout but I would say that yes it would be possible. Are you going to do the work yourself or getting an electrician? If you are going to DIY it then find what supplies your existing bell and find a wireless unit that suits. The wireless unit may be battery powered so only require a switching input.

[CrapAtCryptics]

Lights including PIRs are so cheap why not just replace the whole thing

[Khandro]

beso; //Having to ask this question is a sure indication that you should not being doing this work.//

Thanks for your help. I wouldn't dream of DIY. But I want to know what is feasible in order to explain what I want to an Electrician who speaks in the broadest Swabian.
The typical Swabian tradesman, first tells you (in his almost incomprehensible dialect) that what you want is impossible and then after the delay, in which you become downhearted, tells you how he has found a way to do it, thereby demonstrating how clever he is, expecting accolades, and indicating how lucky you are to have him.
It's amazing that these Swabian folk invented the automobile and have produced some of the world's finest engineers.