Lighting timer

[Harry Bloomfield]

I'm not suggesting this as the solution, but the original solution was a Sangamo solar timeclock, calibrated for local latitude. It would 'calculate' when dusk was due and turn off at a time you preset. I have an ancient one one controlling my LED outside light.

 

[EFLImpudence]

To actually answer the questions:

It is currently wired so that it is switched on with either the switch by the front door, or the PIR.

If that is the case, then -

Is it likely to be possible to add a timer at the consumer unit to set the lights to come on every evening from, say, 6pm to 10pm? Ideally this would be situated next to the consumer unit.

If next to the CU then an additional wire will be required from the timer to the switch, the PIR or one of the lights.

Or will it very much depend on how it has been wired?

Not really.

 

[RichA]

I have checked the CU. It is on the same MCB as half the downstairs lights. I figured they may be separate circuits, but with one MCB?

That TLC switch would work, but is a bit on the ugly side to have in the hall.

 

[EFLImpudence]

I have checked the CU. It is on the same MCB as half the downstairs lights. I figured they may be separate circuits, but with one MCB?

Even if the lights were on a separate circuit, it would still require the additional wire -

unless you wanted the timer to disable the switch and PIR when the timer was off.

 

[JohnW2]

I have checked the CU. It is on the same MCB as half the downstairs lights. I figured they may be separate circuits, but with one MCB?

As I implied, if they were separate circuits (at the CU), there would be separate MCBs. It's not impossible that the feed to the outside light/switch originates (from the GF lighting circuit) close to the CU, but that's pretty unlikely - so you would be very lucky if that happened to be the case!

That TLC switch would work, but is a bit on the ugly side to have in the hall.

If you mean the one with the photocell which JohnD mentioned (even though I'm sceptical about an indoor photocell), as he said, there is a cover which one can close to make it look a lot less ugly!

Kind Regards, John

 

[JohnW2]

In my previous house, I had one beside the front door (which was part-glazed) and one in a room with patio doors and a window

... that's all very well in terms of allowing the indoor photocell to 'see' outside light during the hours of daylight, but it doesn't solve the problem that if a bright enough indoor light is turned on during the hours of darkness, that will turn off the outside lights (if it were a time when one 'wanted' them to be on).

Kind Regards, John

 

[JohnD]

The designers thought of that.

they had a "on at dusk and stay on for X hours" function.

 

[JohnD]

That TLC switch would work, but is a bit on the ugly side to have in the hall.

there are two, the slightly cheaper one looks almost normal when closed.

I have not used the more expensive one, but it tooks like a plain white pad when closed and I believe you can press the pad.

(see top left pic on https://www.tlc-direct.co.uk/Technical/DataSheets/Timeguard/SMZV700B_Instructions.pdf

 

[JBR]

Schneider do a timer where the light sensor is remote fromthe timer body and you link it with just 2 core ELV cable, even cat 5

Thank you. That sounds an ideal solution, as I could run a 2 core cable from the existing switch to the light sensor placed against a window in the adjacent porch.
I have looked for Schneider UK and searched on their web site, but I can't find the object you are referring to. Could you direct me to it, please, or give me any further information?

 

[Harry Bloomfield]

[and, in passing, any idea why it is said that it can switch 400W of incandescent lighting but only 20W of LEDs]

An odd limitation, but be aware it doesn't need/use a neutral so it is dependent on the current passed by the lamp, to provide its power. Some CFL's and LED's will not pass enough current when not lit, to power such devices, without some sort of bypass.

 

[JohnW2]

The designers thought of that. they had a "on at dusk and stay on for X hours" function.

In terms of the issue I was talking about, that would only work if the time of 'dusk' was determined by the timer (which would have to be fairly 'clever'). I thought we were talking about the one with a photocell (I certainly was!) - and if that one is (as it has to be) installed indoors, then if 'indoors' is brightly lit (artificially) at the time when it is dusk outdoors, the outdoor lights will not come on "at dusk" (as desired).

Kind Regards, John

 

[JohnW2]

An odd limitation, but be aware it doesn't need/use a neutral so it is dependent on the current passed by the lamp, to provide its power. Some CFL's and LED's will not pass enough current when not lit, to power such devices, without some sort of bypass.

That would surely result in the opposite of what was being said - i.e. that there was a (perhaps fairly high) minimum for LED switching - not a maximum of 20W.

To confuse the issue even more, the minimum load for switching incandescents is stated as 40W (whereas the maximum switched LED load is said to be 20W)!

Kind Regards, John

 

[Harry Bloomfield]

That would surely result in the opposite of what was being said - i.e. that there was a (perhaps fairly high) minimum for LED switching - not a maximum of 20W.

To confuse the issue even more, the minimum load for switching incandescents is stated as 40W (whereas the maximum switched LED load is said to be 20W)!

Kind Regards, John

Yes, it does sound wrong. Perhaps they meant a minimum for CFL and minimum LED load, to support the switches electronics?

 

[JohnD]

I thought we were talking about the one with a photocell (I certainly was!) - and if that one is (as it has to be) installed indoors,

yes, and you can adjust its sensitivity a bit. Remember it is placed next to the glazed door so it is very aware of daylight. Round about the time you are thinking "hmm, getting a bit dark, I'll turn the lights on" it is thinking the same.

I found it could be overwhelmed by a table lamp placed next to it, but not by the ordinary room lights.

 

[333rocky333]

Thank you. That sounds an ideal solution, as I could run a 2 core cable from the existing switch to the light sensor placed against a window in the adjacent porch.
I have looked for Schneider UK and searched on their web site, but I can't find the object you are referring to. Could you direct me to it, please, or give me any further information?

Schneider cost a fortune.
The Timer is not like a switch, its din rail mounted, usually in an enclosure, the 2 core goes from there to the sensor, sounds like you maybe just need a mains photocell, but you would need a Neutral at your existing switch, to fit a decent reliable sensor, connected at that switch position.
https://www.schneider-electric.com/...&node=166308806-ic&parent-subcategory-id=1650

The astro clock dont need a light sensor its all preprogrammed, we use them instead now and there half the price., but as above its designed for an enclosure , not as a direct switch replacement
https://www.electrical2go.co.uk/san...MIpqu-q_aR4wIVQbHtCh3-0wwREAQYASABEgIVxvD_BwE