multi room fan activation without triggering lights in all rooms

[PeckhamHouse]

Hi all, I'm not an electrician but i need some advice before i hire one to help me complete an installation which was started by a chap who has let me down. I have a large inline fan which sucks air from 4 rooms. it is supposed to be triggered by the lights, which are pir's, in each of the rooms meaning it will suck air from all rooms should one of the lights come one. The issue i face is that the fan has the effect of triggering the lights in all of the rooms should one rooms be opened. I want to know what the solution to this is before i hire an electrician so i can be sure he knows what he is doing. Many thanks for your advice.
Ben
Peckham

 

[amlu]

looks like its been wired with switched lives from every light linked up into fan control terminal?
it should not be designed like that and the electrician will need to figure out how to sort it out...

 

[Marvo]

Yep, it does sound the way ^^^

Depends a lot on the PIR's, if they've only got a single switch contact in them which is being used to supply the light then it's going to get a bit tricky and could require a relay board at the fan to isolate the input signals from each other or possibly a supplementary relay at each PIR to provide two separate switched outputs. Exactly what's involved very much swings on the existing equipment and layout but any experienced electrician should be able to sort this out without too much ado.