Up and down lights, is there a problem??

[mg123]

Hi guys,

I've got quite a few up and down lights outside of my house. 4 on the front of my garage, 1 on PIR and 1 on a switch at the front of my house, and added 6 to the new extension.
Something I've recently noticed with them. the top lights are no longer functioning as they should. They've all become really dim and barely light up. There are several different brands of fixtures, as well as different bulbs. But they all experience this issue.
Do any of you know what causes this, or maybe you've had a similar issue to me? Or perhaps any recommendations to prevent the issue.
I'm really p***ed off with the issue. I guess its something to do with the sun perhaps as it only impacts the top lights.
The bulbs are from reputable source. The garage lights were added early last year. They've not been in use this year as I had a rewire done which meant they're not currently wired in as i'm still doing some work.
The ones at the front of the house were added when the rewire was done by the electrician, and these are the ones I noticed this issue first.
I then tested the ones from the garage and newest ones on the extension. Almost every bulb that's fitted in the up position suffers with this issue.

Any ideas?

 

[Sideways]

Most likely in my view would be a simple case of inadequate design of weather sealing.
Rain will want to run into the upward pointing lights and flow downhill so it will naturally tend to find it's way into the connector with the lamp, into the contacts and even get drawn into the wires between the strands of copper. In all places it will cause corrosion over time and that could cause these problems.
If the bulbs themselves are any good, they will be hermetically sealed. If you were to remove the bulbs and clean them, they should work fine in a good fitting. That would prove the source of your problem.

 

[Sideways]

I don't see any solution to this other than only using good quality light fittings that avoid this problem from the outset.

 

[MarkAW]

Could just be a case that the glass on top is dirty from weather

 

[HamsterJam]

This is interesting.
Not up/down lighters but a couple of years back I had my workshop professionally wired including a LED PIR bulkhead fitting above the door. This is under an overhang and on a Northern elevation so protected from rain and sun.
The first PIR lamp lasted only days and was replaced under warranty. The replacement was the same make/model and failed a few weeks later. The electrician then fitted a third lamp but a different make/model and that lasted several months. I replaced it with a fourth fitting last year of yet another make/model and that has recently failed too.
Each time the failure appears to be the LED lamps gradually giving up, rather than the PIR.
This sounds similar to your problem.
I am wondering what’s causing this. Could it be spikes from the machinery (even though the PIR lamp is hardly ever on when the machines are) or could it be our solar PV? Would an SPD (Surge Protection Device) in the consumer unit in the workshop help? (We already have an SPD in the house).

 

[mg123]

Most likely in my view would be a simple case of inadequate design of weather sealing.
Rain will want to run into the upward pointing lights and flow downhill so it will naturally tend to find it's way into the connector with the lamp, into the contacts and even get drawn into the wires between the strands of copper. In all places it will cause corrosion over time and that could cause these problems.
If the bulbs themselves are any good, they will be hermetically sealed. If you were to remove the bulbs and clean them, they should work fine in a good fitting. That would prove the source of your problem.

I had a similar thought to you, but there is no evidence or sign of water ingress. There are 3 different brands of fitting as well as 3 different brands of lamps which is why I found it odd that they all had this issue. The fittings all seem well designed, the female thread on the up light is at the top and screws onto the fitting itself and the female thread is on the fitting and the cover screws into the down lighter, and also has a rubber gasket so it should present a minimal chance of water ingress.
I'll have to give them a closer inspection and see what I can find

 

[mg123]

Could just be a case that the glass on top is dirty from weather

The glass is clean, I've switched the up and down lamps around to check if it was the lamp or the fixture causing the issue and it is the lamp itself

 

[mg123]

This is interesting.
Not up/down lighters but a couple of years back I had my workshop professionally wired including a LED PIR bulkhead fitting above the door. This is under an overhang and on a Northern elevation so protected from rain and sun.
The first PIR lamp lasted only days and was replaced under warranty. The replacement was the same make/model and failed a few weeks later. The electrician then fitted a third lamp but a different make/model and that lasted several months. I replaced it with a fourth fitting last year of yet another make/model and that has recently failed too.
Each time the failure appears to be the LED lamps gradually giving up, rather than the PIR.
This sounds similar to your problem.
I am wondering what’s causing this. Could it be spikes from the machinery (even though the PIR lamp is hardly ever on when the machines are) or could it be our solar PV? Would an SPD (Surge Protection Device) in the consumer unit in the workshop help? (We already have an SPD in the house).

Sounds highly unlikely in my view. The sockets are on a different circuit to the lighting so the surge shouldn't (I think) cause an issue.

 

[Fergie 307]

I have a single one outside the front door, controlled by a separate light sensor for dusk to dawn. Quite exposed.
Nothing special, just the one out of the Screwfix catalogue that the boss liked the look of. Your post promoted me to have a look and mine are both equally bright. Also still on the original LED bulbs, probably three years old.
Your issue does seem rather odd.
Would be interesting to know the answer if you ever get to the bottom of it.

 

[mg123]

I have a single one outside the front door, controlled by a separate light sensor for dusk to dawn. Quite exposed.
Nothing special, just the one out of the Screwfix catalogue that the boss liked the look of. Your post promoted me to have a look and mine are both equally bright. Also still on the original LED bulbs, probably three years old.
Your issue does seem rather odd.
Would be interesting to know the answer if you ever get to the bottom of it.

If I find out I'll update. It's a big if with my limited electrical skills though

 

[Dabop]

Sounds highly unlikely in my view. The sockets are on a different circuit to the lighting so the surge shouldn't (I think) cause an issue.

Not always- outside lighting can often be found on a fused spur off the power circuits, if that is what is available... (perfectly legal to do so- IF you used a separate fused switch...

One of these usually fitted with a 3A fuse.... (unless you have a LOT of lights or high powered floodlamps, then a 6A might be used instead- whatever is appropriate to protect the wiring used and the load current usage...

 

[Dabop]

As to the top lamp failing- thats 'odd'...
The only thing I can think of is that possibly the top bulbs are exposed to sunlight through the top cover, and are being 'cooked' by the sun (maybe causing the capacitors inside to 'dry out')

That's about the only thing I can think of that could be causing such a result...

(some lamp fittings can in the wrong place become veritable 'greenhouses' inside when direct sunlight falls inside)

 

[trvlr]

I seem to recall reading "somewhere... out there Skully" that led bulbs have a much shorter life if frequently switched on/off (as per a PIR system) than if left on for a while before switching off.

 

[HamsterJam]

Not always- outside lighting can often be found on a fused spur off the power circuits, if that is what is available... (perfectly legal to do so- IF you used a separate fused switch...

One of these usually fitted with a 3A fuse.... (unless you have a LOT of lights or high powered floodlamps, then a 6A might be used instead- whatever is appropriate to protect the wiring used and the load current usage...
View attachment 189591

The set up in my case is a 50A RCB in the house consumer unit feeding approx 30m 10sq mm armoured cable to a CU in the workshop with sockets fed off a 32A RCB plus lighting fed of a 6A RCB. The Main switch in the workshop is a 63A RCCB.
As you’d expect, the outdoor light is fed off the 6A circuit as are 2x 40w LED batten fittings.

 

[HamsterJam]

I seem to recall reading "somewhere... out there Skully" that led bulbs have a much shorter life if frequently switched on/off (as per a PIR system) than if left on for a while before switching off.

Ok - in my case, it could be this. We do get wildlife in the garden that trips the PIR.

 

[Dabop]

I seem to recall reading "somewhere... out there Skully" that led bulbs have a much shorter life if frequently switched on/off (as per a PIR system) than if left on for a while before switching off.

LED's are fine with that- it was compact fluros (and full sized 'fluro tubes') that had issues with frequent switching (it led to 'tube blackening' at the ends where the heaters were located) and premature tube failure...

Indeed in some LED circuits (where they use a string of multiple LED's in series directly across the mains, with special LED's that have two in reversed bias against each other- they effectively 'switch on and off' 50 times a second!!! (ie 50Hz)
This is the circuit diagram symbol for such a diode...

Each LED lights on it's half of the AC waveform- giving the appearance of being on continually...

 

[Sideways]

Flashing LEDs at many thousands of times a second were used for optical data transmission before we started using solid state lasers for that. For the past 20 years TOSlink optical connections on hifi, cd and md players have had LEDs (not lasers) flashing at 100's of thousands of times a second.

 

[ajs]

I'd be suspicious of an installation error with respect to ventilation, LEDs do not kick out anywhere as much heat as other lamp styles but they are quite allergic to the heat they do generate, which is still non-trivial for high powered LEDs used for lighting. If they are gradually dimming over time that is precisely what I'd expect for low level accumulated heat damage, and yes that would affect the bulbs as opposed to the fittings.

These things are not as well standardized are earlier lighting arrangements so you really need to consult the instructions or data sheet for the specific fittings but generally you will need a ventilation gap above downward facing fittings. In particular if these are in the eaves make sure they are not buried under loft insulation.

 

[mg123]

Not always- outside lighting can often be found on a fused spur off the power circuits, if that is what is available... (perfectly legal to do so- IF you used a separate fused switch...

One of these usually fitted with a 3A fuse.... (unless you have a LOT of lights or high powered floodlamps, then a 6A might be used instead- whatever is appropriate to protect the wiring used and the load current usage...
View attachment 189591

I've used fused spurs for lighting in the past, but I meant in my instance the lights in question are on a separate circuit to the sockets.

 

[squib]

As an aside, we had to have a bat survey to build an outbuilding and discovered that uplighters are really confusing for bats so changed all our to the same pattern but just down lights and now only fit these on all projects.