UK Please check my logic for upgrade lights project wiring!

[Lucien Nunes]

RE the backfed to dusk till dawn -- isn't that also the case with the 2 PIR sensors and the manual switch?

They are backfed, but as their inputs are always live, this is a normal situation, their own electronics remain powered by the input. What is abnormal about the sensor is that it can be backfed when the input is dead (due to the timer being off), so if it is active when the timer goes off, the electronics start being powered from the output instead of the input.

If the sensor output is switched by a relay, there won't be any problem; it simply won't notice that the supply for its own electronics is coming in via the output as the relay makes a solid connection. It will go off and stay off once the source of the backfeed itself goes off, and no-one will be any the wiser. If its output is switched by a triac, then it might perhaps object to as the load won't be sufficient to hold the triac on properly, possibly making it go wobbly or cycle on and off while it shuts down. Unlikely though, and probably harmless.

Had the timer been controlling anything else independently, then the backfeed could cause a mis-operation, as it would bypass the timer if both controlled devices were active at once.

 

[renegade]

They are backfed, but as their inputs are always live, this is a normal situation, their own electronics remain powered by the input. What is abnormal about the sensor is that it can be backfed when the input is dead (due to the timer being off), so if it is active when the timer goes off, the electronics start being powered from the output instead of the input.

If the sensor output is switched by a relay, there won't be any problem; it simply won't notice that the supply for its own electronics is coming in via the output as the relay makes a solid connection. It will go off and stay off once the source of the backfeed itself goes off, and no-one will be any the wiser. If its output is switched by a triac, then it might perhaps object to as the load won't be sufficient to hold the triac on properly, possibly making it go wobbly or cycle on and off while it shuts down. Unlikely though, and probably harmless.

Had the timer been controlling anything else independently, then the backfeed could cause a mis-operation, as it would bypass the timer if both controlled devices were active at once.

Got it -- what could be done to work around that issue in this case (I know it is probably overkill, but am interested in options regardless)

 

[davesparks]

Use a timeswitch which has a volt free output to switch the outgoing switched live from the photocell.

 

[Sparky5473]

Use a timeswitch which has a volt free output to switch the outgoing switched live from the photocell.

Just what I was about to write

 

[Kidsolo]

sorry - it wasn't very clear.

The diagram was looking good until you added a house

Send us a picture of the junction box when it is done

It will look just like his diagram, with less straight lines

What is abnormal about the sensor is that it can be backfed when the input is dead (due to the timer being off)

It shouldn't be backfeeding the sensor, it only backfeeds the switch part of the circuit

 

[marconi]

You might want to go through the logic of a timer switch before a dawn-dusk switch; the timer seems superfluous to me.

To avoid running cables to PIR sensors and override switch you could use these wirelessly connected devices to a receiver switch:

EasySwitch Easy Switch Wireless Switches - https://www.tlc-direct.co.uk/Main_Index/Pumps_and_Aquatics_Index/EasySwitch/index.html#EasySwitch

The use of the wireless receiver switch would allow the use of fobs which folk could carry or be left in the car and could obviate the need for the override switch. If you still wanted a separate override switch there is fixed wireless switch which would suit.

Are you bothered about animals or on windy nights swaying trees setting off the PIR for the lighting - it could become annoying.

You might want to think also about beam cutting or retro reflective sensor switches eg:

Takex PR-11B 15m Reflector Beam Sensor - https://connectec.uk/security/intruder-alarms/perimeter-detection/takex-pr-11b-15m-reflector-beam-sensor?gclid=Cj0KCQiAuefvBRDXARIsAFEOQ9GDzyPYfHUOqPWb_5qbAd42I19Gnw5kjYKs1ci9rJVFhd55uzDUvBQaAs_rEALw_wcB