Lamps blowing!!

HappyHippyDad · Apr 11, 2015

Afternoon..

I have been to visit a regular client who has said that some lamps that I fitted having been blowing regularly.

I fitted 11 halogen (ES fittings) outside lamps along a long driveway. SWA along the route sperated with adaptable boxes, from which seperate cable leads up to light.

Approx one blows every 3 weeks and this has been on going for around 9 months.

I am unsure of the quality of the lamp but the client states he has tried various ones with no success.

Voltage is 242V. All connections are well made.

The only 2 things that I can think of are :

1. The set up is the 11 lights come on with a timer OR by one of 2 seperate PIR's (one at top of drive and one at bottom). I cant see how this would be a problem but wanted to give the full picture.

2. I do not like the adaptable boxes, I was using a new type for the first time, they had reasonable reviews but 2 had water inside of them which did not happen with the previous boxes that I am now using again. Poor IR results for L/N-E 0.08MΩ. I have cleared the poor IR results which were due to the water ingress in one of the boxes but wondered if this could be why the lamps are blowing?

Or any other thoughts that I am overlooking?

Cheers all..

HappyHippyDad · Apr 11, 2015

UKMeterman said:
When you say the connectiopns are good are the contacts in the lampholder nice and shiny?

I got very caught up in the fault finding and geting the IR reading above the required standard that I have not looked at that. I will though.

ipf · Apr 11, 2015

UKMeterman said:
When you say the connectiopns are good are the contacts in the lampholder nice and shiny?

If lamps have blown you should be able to tell from those replaced.

Deleted member 72666 · Apr 11, 2015

happyhippydad said:
Thanks Richard,
-The customer did state they had tried 'Phillips' halogen lamps, but I will double check.
-If it is water condensing on the lamp causing the issue, is this because water is condensing on the lamp or the fact it is condensing on a 'poor quality lamp' (I think you'll understand that rather garbled sentence).
-If it was a loose connection then I would expect it to be the same lamp blowing. Plus the connections are good.

Could it not be down to the low (fluctuating) IR results? IR results must have dropped lower at some point as the RCD has tripped once or twice recently, hence calling me in. If there was almost a short between L and E this could have caused too much current to flow through lamp??

Have another rethink on that!

HappyHippyDad · Apr 11, 2015

stantheman said:
Have another rethink on that!

I know.. makes no sense.. all the current would be flowing to earth, not through the lamp! just wanted to try and come up with some ideas!!

Poor quality lamps or lamp holders are looking like the contenders.

Thanks everyone for the ideas.

Deleted member 72666 · Apr 11, 2015

Are the lamps wall mounted or are they on pillars/posts? Just thinking that it's been rather windy these past few months! Don't rule out a combination of faults either such as contamination on the quartz glass, vibration, poor electrical contact (intermittent), poor quality lamps etc,etc,etc.

Marvo · Apr 11, 2015

What else is fed from the same circuit as the lighting? Double check connections and things like a wire or busbar on the wrong side of the clamp termination at the MCB/RCD etc. As already stated check the actual lamp holder where the lamp makes contact for any signs of arcing etc. If the DB is 3-phase try swapping the light circuit to a different phase.

I wouldn't overthink this from a technical point of view, 99% of lamp premature failures are because of something fairly obvious like poor power quality (overvoltage surges and spikes), environmental factors like moisture or vibration and poor terminations or connections etc.

davesparks · Apr 11, 2015

Have you checked that the lamps have actually blown? Poor contact in a lamp holder often manifests itself as perfectly fine lamps appearing to blow.

sparkdog · Apr 11, 2015

I believe the UK mains voltage is a factor,supposed to be 230V but I have seen it above 250V in places.

davesparks · Apr 11, 2015

sparkdog said:
I believe the UK mains voltage is a factor,supposed to be 230V but I have seen it above 250V in places.

Supposed by some muppets in offices who haven't got a clue. LV is , and will be for the foreseeable future 250V at the output of the substation transformers

UKMeterman · Apr 12, 2015

Somtimes it can rise even higher than 253, check the lamps are 240V variant Detailed specifications on EcoClassic Standard lamp 872790025179125 and not the 220V

davesparks · Apr 12, 2015

This was our distro the other night just before shutdown

[ElectriciansForums.net] Lamps blowing!!

UKMeterman · Apr 12, 2015

I have seen 264 that did get the DNO to get arse into gear...

NDG Elecs · Apr 12, 2015

As someone said are the fittings wall mounted or are they posts along the drive. I find eco halogens do not like any kind of vibration. Also you said it was 9 months at least since they were fitted. If the lamps get a lot of switching then they may be coming to the end of their lifespans.

I had a client that had fancy ceiling lights in three rooms. Each fitting had 12 G4s in them. So 36 in total. If each lamp is rated to last a 1000 hrs then when they start to fail it can seem like an endless cycle of changing lamps as knacked ones need replacing. That's partly why some offices etc have all lamps replaced on a relamp regardless of whether they still work.

If all seems OK with the install I would be tempted to put a couple of LEDs in and see if they last better. If they do you can point this out to the client. The UK voltage and European market prob don't help matters either!

NDG Elecs · Apr 12, 2015

happyhippydad said:
I always do Murdoch, this time I got taken in by a cheaper box from screwfix (still not the cheapest though!) with reasonable reviews (I had used it once or twice before and it seemed fine, however with 11 of them it became evident it was poor quality). I have since reviewed the box and also mentioned about it on this forum in a thread I started as I was so disappointed with it.

Still silly though!

Link to the boxes please HHD so we know to avoid them!

Knobhead · Apr 12, 2015

HHD, admit you don't know what you're doing.

One of the things I had to study at engineering college was “test methods and reliability.” We used lamps as a case study, all the major suppliers provided samples for endurance and switching tests. The manufacturers can almost guarantee when the lamp will blow when in constant use, IE endurance test. Switched on a regular basis, the time reduced by more than 50%.

Look at the switching.

Sylvania came out as one of the most reliable in endurance.