Photocell and time clock on same circuit

[Dazza1976]

Hi all,

As per title, I seem to see this quite a lot especially in new builds where a time clock and photocell are both wired intro the same circuit for communal lights. What is the logic behind this ? Surely it’s better to have just one or the other, as the photocell will not operate the lights if the time clock is not on and vice Versa, also it’s just adding another device that can fail, I just don’t see the point in having both ?
Probably a simple explanation that will make me look stupid ! l
Look forward to your responses.

 

[brianmoooore]

Usual arrangement is that the photocell turns the light on (when it gets dark) and the timeswitch is used to turn it off at some point in the night.
I have that set up here, in a dark area between one of my holiday cottages and their garden/dog toilet. Switches the light on at dusk, and off at 11.30 PM.

 

[DPG]

Yep, as above, it saves the lights being on all through the night and early hours of the morning.

Mine come on at dusk and go off about 10.30PM. But I do it with a smart socket and a Google home routine, so no need for any actual timer or photocell.