Photocell to control multiple outdoor lights

I have 3 outdoor wall lights, one is controlled by an indoor switch and the other two are permanently live but have built in pir's. I would like to replace all three lights and add a photocell so they come on automatically at night. I've looked at the wiring and each light is fed with just one twin and earth cable and since the same switch on the consumer unit switches power to all lights I presume they all connect back to a common point somewhere in the ceiling space. I have no idea where that point will be so will I have to install 3 separate photocells to control each light independently or is there a way I can add just one photocell to control all three?

Almost impossible to answer 100% without proper tests and checks ......

Are these three lights the ONLY lights on the circuit from the fuse box?

Or does the same fuse (MCB) supply other lights in the property as well??

IF they are the only lights, AND you can get wiring from your proposed photocell back to the fuse box... (3core+Earth)

then it should be relatively straight forward to bypass the whole circuit supply so it is only live after dark..

But if not, you are going to have to find all of the junctions where the three lights branch off the circuit supplying any other lights elsewhere..

At the end of the day, Everything is do-able....

But it may be cost, disruption and time prohibitive trying to trace wiring,

compared with just fit 3x photocells.

The advantage of individual cells of course is if one fails you still have two lights working, compared with no lights if they are all controlled by a single cell.

Guinness

SPECIAL LOCATION said:

Are these three lights the ONLY lights on the circuit from the fuse box?

Or does the same fuse (MCB) supply other lights in the property as well??

IF they are the only lights, AND you can get wiring from your proposed photocell back to the fuse box... (3core+Earth)

then it should be relatively straight forward to bypass the whole circuit supply so it is only live after dark..

But if not, you are going to have to find all of the junctions where the three lights branch off the circuit supplying any other lights elsewhere..

At the end of the day, Everything is do-able....

But it may be cost, disruption and time prohibitive trying to trace wiring,

compared with just fit 3x photocells.

The advantage of individual cells of course is if one fails you still have two lights working, compared with no lights if they are all controlled by a single cell.

Guinness

Click to expand...

Thanks for this advice. I'd not even considered they may be the only lights on the one circuit so I'll do some checks tomorrow. 

I suspect there are other lights on the same circuit and it would be way to much disription to locate wiring so fitting 3 photocells may be the way forward. The real downside to this is that the wiring will all have to be external in conduit so won't look as tidy.

Cheers

Shev said:

Thanks for this advice. I'd not even considered they may be the only lights on the one circuit so I'll do some checks tomorrow. 

Click to expand...

The way I normally find out what lights are on what circuit is...

1/ Walk around the property and switch every light in the house ON..

2/ Go to the fuse box and turn the first lighting fuse OFF...  walk back round the property and write down which lights have gone OFF.... then turn that fuse back ON again.

3/ Repeat step 2 for the second light fuse..

4/ Repeat step 3 for any more lighting fuses that are on the fuse box..

You will now have a list of Every light and which fuse they are supplied from.

AND you should have every light in  the house accounted for..

If some lights NEVER went off, they may be supplied via a fused spur on a socket circuit..

So need to redo 2-3-4  for the socket fuses as well.

Guinness  

^^ and when you’ve done that and some lights stay on, repeat the exercise, but switch off each MCB at a time and leave them off ..... as having linked connections on older setups isn’t unheard of ....

Murdoch said:

^^ and when you’ve done that and some lights stay on, repeat the exercise, but switch off each MCB at a time and leave them off ..... as having linked connections on older setups isn’t unheard of ....

Click to expand...

Glad someone who's 'been-there-done-that-got-the-Tshirt' is keeping an eye out.... 

Just in-case I missed something!!!   :Salute   :innocent

OR...  

to summarise...

Almost impossible to answer 100% without proper tests and checks ......

:slap   Guinness

SPECIAL LOCATION said:

Glad someone who's 'been-there-done-that-got-the-Tshirt' is keeping an eye out.... 

Just in-case I missed something!!!   :Salute   :innocent

OR...  

to summarise...

Almost impossible to answer 100% without proper tests and checks ......

:slap   Guinness

Click to expand...