Advice needed

John Palmer01 · Jan 27, 2024

Hi all,

I am a general builder that is taking on a complete renovation on a property for my good lady and myself.
I am not an electrician but like to have an understanding of works that I request others to carry out for me.
I will have an outside light fitted on the driveway which I would like to be constantly on until 10pm. After that I would like it to be on pir.
I was wondering if it was permitted for a permanent supply and a timed supply to be run to the same light?
I also have a similar question for the internal lighting.
I have a hallway that will require pir sensors fitted at each end.
Is it permitted to have the 2 x sensors running to the same light?

I would appreciate any advice given.
Thanks.

Geoff1946 · Jan 27, 2024

Nothing difficult about your ideas, BUT, presumably you don't want the outside lights on until dark, so do you want a photocell, or perhaps a timer? Do you want to be able to override the controls with a manual switch, either on or off? These are things you need to consider and specify carefully to your electrician to avoid difficult afterthoughts.
In the hallway, there's no problem with two sensors, but similarly, do you want it always automatic?

John Palmer01 · Jan 28, 2024

Geoff1946 said:
Nothing difficult about your ideas, BUT, presumably you don't want the outside lights on until dark, so do you want a photocell, or perhaps a timer? Do you want to be able to override the controls with a manual switch, either on or off? These are things you need to consider and specify carefully to your electrician to avoid difficult afterthoughts.
In the hallway, there's no problem with two sensors, but similarly, do you want it always automatic?

Hi Geoff,
Thanks for the reply.
I wanted the outside light on a timer so that it stays on until 10pm. But then be controlled by pir in case we come back late. I am not worried about a manual switch.
I have young grandchildren stay at weekends so pir sensors is ideal when they wander around during the night.
The pir can be adjusted to only activate when it is getting dark.
I know the theory is OK, but was wondering if 2 x separate supplies feeding a light is permissible.

Geoff1946 · Jan 28, 2024

Yes it's OK. It's not really two supplies, just two sensors/controls, both supplied from the same circuit breaker.
The only difficulty which will arise is in adjusting their light sensors/sensitivity/timer adjustments as you can't tell which one is putting the light on at any time.

My point was that you need to write down ALL your assumptions, such as having ones with light sensors, or your electrician may make different assumptions leading to disappointment all round.