Light to turn on when opening automatic garage door

Linbury · Jul 7, 2020

Hi Everyone,
I have the (luxury) of an automatic garage door. The motor to this door is powered by a standard 3-pin domestic plug. There is a standard on/off light switch in the garage to turn on these 6 LED battens (https://amzn.to/38BJ5ws) in there. The lighting circuit is on a separate circuit to the garage door motor.
I would like to add another switch to this lighting circuit so the lights turn on automatically as soon as the garage door is opened. (I want to keep the existing on/off switch to act as an over-ride switch, so I can keep the lights on if I wish when the garage door is closed.) A PIR wouldn't be suitable as 99% of the time, it would be used when I open the door from the fob whilst I'm still in my car, so wouldn't be able to pick up IR "heat" from that far.
So, I was thinking of using a microwave switch, that would detect any type of movement or some type of other switch that would detect when the garage door is opened. The garage is detached from the house.
Can anyone help with what type of switch would be best?
How would I wire it up to the existing lighting circuit?
Kind Regards

westward10 · Jul 7, 2020

The forum has a policy of not giving step by step advice members with little or no electrical knowledge. Whilst we can advise in some circumstances your project is beyond our policy of giving a bit of advice. Your best option is to seek the services of an electrician to ensure this is done in a safe manner.

Lucien Nunes · Jul 7, 2020

But it's OK to suggest possible solutions in principle, surely, if wiring instructions and component details are not given?

Some garage door openers have an output to feed a light that switches on when triggered by the fob - check the specifics of your model. Because the door motor and lights are on different circuits, a relay would be needed to interface between them so that a dangerous interconnection of the two circuits does not occur.

If your door opener does not have a light output, a current-sensing relay could be installed in its power cable, set to ignore the tiny load of the radio receiver but trigger when the motor starts up. The same precautions applies about maintaining separation between the lighting and motor wiring.

Or, as you originally visualised, a proximity switch could detect the position of the door.