external LED floodlight PSU issue

Irish Steve

Local garage has 4 external LED floodlights, 20W each unit, and they are switched by a common PIR detector, so they all come on when there's movement during darkness. Due to the location, that switching is pretty regular, and the result of that is that all 4 floodlights are now not working correctly, and my suspicion is that the internal power supplies are just not up to the job where they are being switched so regularly.


Not sure yet what the voltage pushed out is, but the temptation is to rip the power units out of the heads, and replace them with one heavier duty unit inside the building, the way they have failed suggests that the LED units are OK, they sometimes come on for a short while, or the LED grid is illuminated at a low level, suggesting low voltage from the power supply, and they are clearly temperature sensitive.



I'm not confident that replacing the complete units is going to provide a solution, and they are higher than working from a ladder height, so a pain to get to for maintenance, and I don't have too much confidence that replacing the complete unit will actually solve the problem, it's the high switching rate that's causing the issue.



Anyone got any suggestions about a source of supply for a suitable power supply unit that is less likely to be upset by regular switching cycles? North Dublin or Meath ideally, but if we have to get them from further away, that's what will have to happen.

Hintel

You could do it as a project.but.its more.practicsl just replace them

I didn't think frequent switching was a problem.with.leds

Irish Steve

Hintel wrote: »

You could do it as a project.but.its more.practicsl just replace them

I didn't think frequent switching was a problem.with.leds

Nor did we, that was one of the reasons for putting LED's up there, rather than the older technologies, but they have all failed in the last couple of months, so there is clearly a weakness there, maybe it was just that manufacturer or batch, but once bitten twice shy, it's a tower job to get up to replace them, so if we have to go up to replace them, I'd like to hope that we won't be going up to replace them again too soon. The LED's should have a long life, but if the power supplies are not reliable, my thinking is that having one internal that's accessible and well specified should resolve the problem.

GreeBo

Can you look at adjusting the PIR to stop nuisance tripping?

Irish Steve

The PIR is doing what it's supposed to, detecting motion, and the problem is that when motion is detected, it's not easy to determine if it's a nuisance activation as such, which is why it's there. We have it set down to a level that's appropriate, the issue is that the LED floodlights clearly don't cope well with that demand, which was not expected.

GreeBo

Irish Steve wrote: »

The PIR is doing what it's supposed to, detecting motion, and the problem is that when motion is detected, it's not easy to determine if it's a nuisance activation as such, which is why it's there. We have it set down to a level that's appropriate, the issue is that the LED floodlights clearly don't cope well with that demand, which was not expected.

Its not going to solve your current problem, but you can point the PIRs so that they only see areas that you care about movement in (rather than switching everytime a car drives by for example)

Irish Steve

Already done that, but there is a lot of movement in the areas of watch. If we set it tighter, we will be missing peripheral activity, which needs to be detected. It is very much a case of finding power supply units that can cope with the level of switching, which the LED's currently in use can't do.

Blanchguy

You may run into problems with voltage drop if you are trying to push low voltage a long distance from a remote psu. Depends on your layout, but something to think about.

2011

A few thoughts:

1) Don't switch as frequently by adjusting the timer to maximum. As these are LEDs the running cost is very low.

2) It is best to have a motion detector per LED. This reduces the number of single points of failure. It also means that it limits the number of lights on to one per nuisance trip.

3) Buy a high quality fitting such as Stinel, install and forget

listermint

PIR should not impact good quality LED's.

Ive had middle of the road ones fail as described here, in the space of a year. Very disappointing because they were not cheap.

But a high quality one should not dying at all. High quality doesnt mean expensive btw. There are various grades available on amazon for example that will operate excellently.

As above

1- all should have their own PIR
2- Spiders can and will be attracted to the PIR, I put gear grease around the casing of my PIR's and it stopped misfires by 80%. (use gloves )

Irish Steve

I guess that's the $64K question, the problem being that local electrical wholesalers are likely to be stocking the cheaper brands, because they will sell, and in the face of competition, if someone wants a quantity, if there's a choice between €20 and €40 (as an example) they are unlikely to sell too many at €40, and the problem is trying to decide what's good quality and what's cheap and cheerful tat that won't last, and I'm long enough in the tooth to know that the highest price is often not the best, but working out which of the middle of the road units is the best quality is not easy. The fact that all 4 have failed within a short period of time tells me that I need to avoid that brand going forward, but it's very hard to work out who makes the better quality, and where they got it from, the name on the box is no help in a lot of cases.

We'll see where this goes.

10-10-20

What's the Vdrop for the LED strings?

2011

Irish Steve wrote: »

I guess that's the $64K question, the problem being that local electrical wholesalers are likely to be stocking the cheaper brands

Buy online, simples
I just bought a 20W Philips LED floodlight online. Small money, quick delivery.

they are unlikely to sell too many at €40

That depends on the wholesaler. Plenty of good wholesalers sell quality kit (Kellighers, Eurosales etc..).

Irish Steve

2011 wrote: »

Plenty of good wholesalers sell quality kit (Kellighers, Eurosales etc..).

Probably true, but getting to some of them could be "interesting" with the restrictions in place, it's arguable wether getting replacement security lights is an essential journey, presuming they are open for collections. Delivery might be a possibility, depending on how they are operating though, will explore that option.



Thanks