Pir external light fault.

[dreamwarrioruk]

Hi to all,
Just come across a situation which I havnt encountered before and could do with some advise as why its happening.
Customer has a pir lantern outside. This works as per normal detecting movement down the driveway. However they have noticed that if the turn on the bathroom light on a night then sometimes the pir will actually activate the lantern. I have checked the connections, no 2 way switching or anything like that and the lighting is on the same circuit in the house. Only thing remotely close is the l/n and s/l are into the same jb in the loft but not miss connected. Would a neutral fault cause the pir to activate.
As yet I have not done anymore extensive testing on the circuits. And would rather get some more information before I start ripping into the circuits.
Dis board is split load with 2 rcd. mcb is 6 amp "B", cables old colours in 1.0mm twin. Apparently the property was rewired in 2009. Obviously not completely though.
Has anyone come across this before
Regards

 

[malcolmsanford]

Is this something that as developed or as it always happened.

If it's just developed I would tend to look at the lantern and it quality. Unless it is of a good make and no bought from a DIY shed, then chances are the sensor is breaking down and with it being on the same circuit as the bedroom light, the inductance of activating the bedroom light is triggering the PIR.

Best way really to check is to replace the lantern.

 

[i=p/u]

when a big noisey lorry goes past my house the light comes on even tho its more thasn 12m away from sensor..

 

[needasparks]

Is the bathroom light an inductive type ? or switching a fan also.

Whoops just seen malc's post.

 

[dreamwarrioruk]

Thanks so far, yes the bathroom light is inductive (must admit i had forgotten about this potential issue) and the actual unit was a rather cheap plastic affair, bought last year from a certain "non trade outlet" that offers many types of building, garden, kitchens and bathrooms (without nameing anyone). Have changed the unit this morning for a better quality fitting and advised customer to see if the problem continues.