Surge Suppresser for LED Floodlight: High failure rate

[Andrew Mawson]

I have a 100 watt PIR Floodlight mounted on the gable end of my tractor shed:

First one was fitted in August 2017 and the sixth (yes 6th!!!!) replacement is on the way to me as I type. Now my mains is not excessively high varying usually between 235 to 240 (I log it on my UPS). Now admittedly I have some equipment with large motors, but not on the same circuit or feed from the dis board, but I DO have three of the non PIR version of the same 100 watt LED flood light inside the tractor shed fitted also August 2017, and so far non have failed.

There is no sign of water ingress on the failed units, but TLC can give me no feedback from the manufacturer as to the failure mode. Before I re-fit the latest one, which involves a very long ladder over a vast chasm of a door, I wonder if fitting some sort of surge suppressor 'just in case' might be sensible?

Has anyone any experience of such failures or mains surge suppressors in general? A quick peek at RS components show that they can be pretty spendy :(

Andrew

[Adrian Brentnall]

I did have problems with some LED candle-bulbs, running from the same

4-way extension lead as some fluorescent tubes. Apparently the LED bulbs don't like voltage spikes.... - these were straight bulbs rather than PIRs.

You might get away with one of the 'transorb'-type devices, fitted at the LED floodlight ? If I remember rightly, these things clamp any voltage spikes, available in different voltage ratings. Don't know how long they last (as in how many 'clamps' before they give up)

Adrian

[tabbypurr]

short answer is no. The mains feed has a far lower impedance than any little surge absorber, making them pretty useless. You're just paying for a fire hazard.

If running kit from a generator they have their use, but not with mains.

NT

[Peter Parry]

While some have few components inside and do little the half decent ones have a snubber followed by a couple of chokes, a bank of VDR's and assorted capacitors. The impedance of the mains is irrelevant as the VDR's and filter capacitors come after the inductors which have already trimmed any fast rising spike quite well.

[Peter Parry]

I've used some very big Oeac Micromates which solved a severe mains interference problem. I've also got a couple of much simpler mains surge protectors from Inmac / RS which were in Shuko cases but the PCB's were removed. These comprise an input snubber, 3A fuse, twin choke, followed by 4 VDR's and 3 capacitors filtering the output. Never used, left over from the aforementioned project. If you want one to try you are welcome, its just a bare PCB so needs some sort of box or an apprentice to hold it for a few weeks.

[Andrew Mawson]

Yes please. My reply to address is easily de-munged :)

Andrew

I've used some very big Oeac Micromates which solved a severe mains interference problem. I've also got a couple of much simpler mains surge protectors from Inmac / RS which were in Shuko cases but the PCB's were removed. These comprise an input snubber, 3A fuse, twin choke, followed by 4 VDR's and 3 capacitors filtering the output. Never used, left over from the aforementioned project. If you want one to try you are welcome, its just a bare PCB so needs some sort of box or an apprentice to hold it for a few weeks.

[Harry Bloomfield]

Andrew Mawson expressed precisely :

I would suggest that the failing lamps or the PIR are likely of poorer quality that the ones without the PIR's, rather than it being due to any surge issues.

[tabbypurr]

Seldom is anything due to 'surges' of the sort that plug-in 'surge arrestors' do anything about. Put them on the list with magnetic water softeners.

NT

[Brian Gaff]

Could it be environmental in nature, heat and cold? Brian

[Graham.]

You seem convinced that the failures are caused by mains spikes. I'm not saying that they are not but I'm wondering if TLC planted that idea into your mind?

[Andrew Mawson]

You seem convinced that the failures are caused by mains spikes. I'm not saying that they are not but I'm wondering if TLC planted that idea into your mind?

[Chris J Dixon]

Is it the number of switching operations that is killing them? I have a PIR for my kitchen downlights, and have had a shorter life than would normally be anticipated. The small print shows that they are affected by too many operating cycles.

I have had some replaced, but return postage costs are a big chunk of component value.

Chris

[Andrew Mawson]

In fairness TLC have been brilliant replacing them, and delivering the replacement usually on the same day that I report the fault.

In the location that it is, it isn't triggered very often at all. I've set the field of view to be effectively just the concrete apron in front of the tractor shed, and it's only the odd passing fox or badger that sets it off at night. My usage is usually daytime when it is inhibited anyway.

Andrew

[Harry Bloomfield]

Andrew Mawson was thinking very hard :

A great deal of imported electrical items, are designed for 220/230v and the soon fail on the UK's more usual 240v.

So far, you have only suggested they fail. Is it the lamps failing or the PIR?

[tabbypurr]

they fail because they're junk, not adequate for the job. I would not have accepted a 6th replacement myself. Or a 5th, or a 4th.

NT

[Martin Brown]

They are probably not on at the time when whatever kills the other one happens then. If it was a filament bulb excessive vibration might be a candidate (it could still be for a circuit board but less likely).

Does your UPS log mains spikes? You could forgo using it on your PC and set it up to monitor the dodgy circuit for a while.

I doubt that a surge suppressor will make any real difference. My experience of them is that they will more often save themselves by allowing whatever they are supposed to be protecting to fry :(

Things that might be life shortening for it could include electric arc welders nearby, kilns or big three phase motors. Local sewage pumping station switching on at 6pm used to kill plenty of stuff round here (before they upgraded the mains feed to the village).

Shame they don't tell you how it died. Be worth checking to see which of the LED and PIR components is still functioning next time one fails. Chances are one of them is still perfectly OK.

Good luck fitting the replacement.

[Andrew Mawson]

Impossible to tell. The unit doesn't function and is not openable !

Andrew

[Andrew Mawson]

Replacement fitted and functioning - taking bets on for how long !

Andrew

[The Natural Philosopher]

[Harry Bloomfield]

Martin Brown pretended :

Do PIR's still use a relay to switch the load? Perhaps the tick or lack of, of the relay might give a clue?