HELP! Moved into a New Home with Earth > Switch Live in a PIR?!

[Mascott]

Hi folks,

I've recently moved into a new home (7 days ago) and wanted to do what I thought would be a simple job of removing a grubby old porch light, disconnecting its associated PIR, and replacing the lamp with a Phillips Hue Outdoor light, and then would configure a Phillips Hue outdoor wireless PIR.

Having turned the circuit off at the consumer unit, I opened the old PIR to find what appears to be "Earth" running to the PIR's switch-live...!

The white cable coming into the PIR box goes straight to the consumer unit.

The black cable going out from the PIR box goes to the porch lamp. This lamp has two further cables going into its enclosure, but my appetite for getting my hands dirty diminished significantly as soon as I saw the earth > live, so I have not opened this up, but presume one goes off to a switch inside the front door (which does nothing) and the other to something else (and at least the doorbell, as this is no longer chiming with the breaker off). The breaker is unhelpfully just labelled as "Door Switch".

I should note the existing lamp does come on and off at night with the PIR, but not with the switch I believe it's also connected to.

Now, has someone done something "cowboyish that works" leaving me ok to just replace the whole PIR unit with an outdoor junction box as I had intended, (E>E, L>L, N>N), or does the Earth > Switch Live and the functionality I've described above mean something more ominous.

Due to the fact the switch faceplate inside the front door that I believe this is connected to the lamp is metal, I have for now left the breaker off have a very dark front of house, and hope someone can shed some light (no pun intended) on what might be going on while I try to find an electrician with availability this side of the Christmas break.

Cheers,
Mascott

 

[EFLImpudence]

Well, it is not "the Earth" that is connected to the Switched Live but a Green and Yellow wire.
This use of G&Y wires has only recently been prohibited by the regulations.

I would hazard a guess that this has been done to enable the switch to override the PIR, but you say it doesn't work.


The metal switch could still be correctly earthed by the G&Y wire in the supply cable.

A picture of the wires in the switch would probably be helpful.

 

[Risteard]

Well, it is not "the Earth" that is connected to the Switched Live but a Green and Yellow wire.
This use of G&Y wires has only recently been prohibited by the regulations.

I would hazard a guess that this has been done to enable the switch to override the PIR, but you say it doesn't work.


The metal switch could still be correctly earthed by the G&Y wire in the supply cable.

A picture of the wires in the switch would probably be helpful.

It was never permitted to use green/yellow as a live conductor. It has to be correctly identified (e.g. with sleeving). At one time only green/yellow singles couldn't be remarked, but at other times it was any green/yellow conductor. The photo displayed has never been permitted.

 

[SUNRAY]

It was never permitted to use green/yellow as a live conductor. It has to be correctly identified (e.g. with sleeving). At one time only green/yellow singles couldn't be remarked, but at other times it was any green/yellow conductor. The photo displayed has never been permitted.

I've never been aware the green or green/yellow in a multicore cable is forbidden to be used for an alternative purpose, however that shown in the image should have been marked as a live conductor with brown sleeve or some other acceptable method.

My understanding is green/yellow single has been/is specified as not permitted for any other purpose.

I don't hold any regs other than 2004 brown book and therefore unable to verify at this time what the current situation is.

I believe I'm saying the same thing as Risteard.

 

[Murdochcat]

Oer a 3A mcb

 

[SUNRAY]

Oer a 3A mcb

?????? is that a problem?