LED Security lights Come on When Extractor Fan Switched off Ask questions and find answers to many subjects relating to electrics and electrical work

[MOEC]

Just had electrics connected to my house extension, shower room has lights and fan on double gang switch, utility room has lights, fan and outside LED Security lights on triple gang switch, problem is when I switch off the fan in shower room or utility room the outside security lights come on( this only happens after dark).
Had my spark round the other night, he has never seen this before, (he thinks it maybe some feed back after fan is switched off)has anyone experienced this before and any idea how to fix it.

[Mr White]

It does sound like it is a spike / back emf.
I would change the one of the lights and see what happens.

18:50 28/11

[MOEC]

[quote="Mr White"]It does sound like it is a spike / back emf.
I would change the one of the lights and see what happens.

18:50 28/11[/quote]
thanks will talk to my Spark and give it a try.

[ericmark]

Passive inferred (PIR) looks for a temperature change, so if the fan is blowing out hot air then stops there is a change, so lamp turns on.

It is common to have this problem where a central heating boiler flue is pumping out hot air, more common when it starts than when it stops but can be either.

Normal cure is put a baffle so the light can't see the hot air until it's cooled enough not to effect it.

It does not detect movement if detects change is inferred heat, if I reverse car up drive light will not come one, come in forward it will, as radiator is at front of car.

Also summer open car door and nothing, but winter I have the car heater on, so as I open the door hot air from car turns on the light, in summer I have to get out first so it sees my body heat.