Lights switching on via occupancy detectors every time the external door is opened and the door alarm sensor activates. The alarm and lights are on different circuits, and cables do not run in close proximity to each other. Has anyone had this before?

I'd guess the occupancy sensor is on a suspended ceiling & when the door is opened the tile is moving enough to put the lights ons....

 

What is the "door alarm sensor" - just a contact ?

The door alarm is a contact with a buzzer that sounds on the alarm panel. The ceilings are plastered and the sensors are not on the same floor as the external door

Loose connection?

Surely the occupancy sensor is just doing it's job? Assuming there ultrasonic or microwave and not IR.

If the only thing "connecting them" is the audible sound of the chime on the door have you disabled the chime to test?

The occupancy sensors may need adjusting.

Also who's John, the resident ghost?

1 hour ago, ffrowley said:

The door alarm is a contact with a buzzer that sounds on the alarm panel. The ceilings are plastered and the sensors are not on the same floor as the external door

 

What's your relationship in this ?

 

Your alarm, your electrics or your building ?

-I'm sure the sensors are IR I'll have to have a look when I go back.

-I haven't disabled the chime yet...

-I've installed the lights with occupancy detectors

 

44 minutes ago, ffrowley said:

-I'm sure the sensors are IR I'll have to have a look when I go back.

-I haven't disabled the chime yet...

-I've installed the lights with occupancy detectors

 

So have you damaged a cable somewhere or left something loose , all possible 

Could possibly have a damaged cable or loose connection on the alarm side. How would that switch an occupancy detector for a lighting circuit on tho? These circuits are both separate?

2 hours ago, ffrowley said:

-I've installed the lights with occupancy detectors

 

Its very unlikely the alarm is doing something to trigger the occupancy sensor.

 

Mask your sensor(s) over with electrical tape, open door external *IF* there's a weird interconnection between the systems your lights will come on.

 

I assume opening the door is causing something to move within the area of the occupancy sensors eg- blinds, house plants or some weird reflection on the glass of the opening door reflecting onto the glass of another building into the room with the occupancy sensors

 

Reducing the sensitivity of your occupancy sensor(s), is where I would start.