What's going on here?

[RazzyRascal]

Afternoon chaps.

I've got a wall light outside my house and with the nights drawing in I have decided it needs to be recomissioned into service.

The old fitting is past it, so I've purchased a cheap screwfix wall light.

Theres a PIR sensor about a metre away on the wall which I suspect switches this light.

Anyway, before I fit my new light I have checked out the wiring on the existing fitting, hoping to swap it over, but I cant make sense of what's going on. It's the two feeds that's confusing me.

Any ideas?

Thanks in advance!

 

[EFLImpudence]

It looks like it is wired for an ordinary on/off switch.

 

[terryplumb]

One cable is the feed ,L.N and earth, the other takes a live to the sensor and returned switched live to the fitting. So one of the black conductors is a neutral and the other is the switched live from the sensor.
There is a black cable close to the sensor ,where does it go / what is it for ?

 

[chivers67]

It looks like the power comes in via one Red - goes off to the Sensor (the joined Reds) then the sensor "switches" the power on via the return switched live (in this case an unmarked Black) then into the light then back via the neutral.

The Sensor looks like it's on the way out

 

[EFLImpudence]

That would mean the PIR doesn't have a neutral.

 

[RazzyRascal]

One cable is the feed ,L.N and earth, the other takes a live to the sensor and returned switched live to the fitting. So one of the black conductors is a neutral and the other is the switched live from the sensor.
There is a black cable close to the sensor ,where does it go / what is it for ?

Thanks terryplumb.

The black cable close to the sensor is a badly installed satellite cable.

 

[RazzyRascal]

The Sensor looks like it's on the way out

Well on it's way out. Funnily enough you can still hear it click! I have a cheap screwfix replacement.

 

[RazzyRascal]

With light removed

 

[terryplumb]

Some sensors require a neutral ,and there doesn't appear to be one to the current sensor.

 

[RazzyRascal]

Now, I wired this up, like for like, but theres clearly something wrong as the light is constantly on...

 

[RazzyRascal]

I've learnt a lot in the last few months DIY'ing, but my brain does cartwheels as soon as I look at a wiring conundrum. I know it's best left to professionals but I though I could handle an outside light!!!

 

[RazzyRascal]

Some sensors require a neutral ,and there doesn't appear to be one to the current sensor.

The PIR has a LNE feed. Presumably I wire the live to the live and neutral to the load?

 

[terryplumb]

Using the old sensor ,or a new one ?

 

[RazzyRascal]

Using the old sensor ,or a new one ?

I have a new one terry.

 

[RazzyRascal]

Now, I wired this up, like for like, but theres clearly something wrong as the light is constantly on...

I should clarify - the only way that light turns off is via the fuse box!