Lighing failing all over the place at random

[RedTomato]

Hi DIYNot,

So I had my house completely rewired a couple of years ago before moving in. (Needed it as wiring dated from 1940s. Fancy sitting in a bath with a bare 1940s 2-bar heater dangling from the ceiling over your head?)

The electrician seemed nice at first (don't they all?) then his hat grew to 10 gallons. Left light switches live with so much wire bulging behind them that they couldn't be screwed into the wall - this was after we + 2 young kids moved in. 'Oh, tell your kids not to poke their fingers behind the switch. I'll sort it out later" (never happened).

Got rid of him. Council inspected wiring, seemed happy with it. Most of our lights are recessed downlight MR16 (GU5.3) 12v 50watts. 35 of em! (kitchen, living room, bathroom, hall, various alcoves etc)

Never have I seen such a shabby light installation. Bulbs blow all the time. Sockets die and need replacing. Lights flicker like mad both on full & when dimmed.

Got in a second electrician, told us all the transformers needed replacing. Charged us a grand to do it. Lights seemed fine for a while.

Now they are flickering & failing again. Two transformers were blown. I replaced them myself (not that hard) which sorted out the issue for these particular lights. Need your help on remaining issues:

1. Should I just rip out all the MR16 sockets & replace them with something else? With what?

2. The sockets seem to fail all the time - I seem to be replacing them almost on a monthly basis. This is a pic of what I'm replacing:

Every time I have to take the recessed fixing out, it damages the ceiling plasterboard more and more. I'm getting fed up of this.

3. Bulbs failing all the time. I have noticed that when I take a blown bulb out, almost every time one of the two pins is gleaming & the other one is deeply tarnished. Sandpaper the tarnish off & put the bulb back in, bulb half the time is working fine. What's going on?

4. Lights flickering when dimmed. All the dimmers are Aurora 2-way dimmer AU-DSP400, min 60W max 400W. I noticed the second sparky replaced a couple of misbehaving Auroras with Hamilton Litestat L400/2, min 50w max 400w, which seem fine. Should I replace the remaining Auroras with the same model Hamiltons?

Fusebox is Wylex, 2 banks of 4 fuses, + 2 RCD's. I can't find a spare transformer right now but will take one out if you ask.

Thanks for any advice.

RedMonty (Experience: careful semi-competent DIY'er, first time house-owner)

 

[securespark]

Your SELV lampholders are burning out.

Are they overheating?

One issue often overlooked is that of a fitting being fire-rated, and the fitting has the incorrect type of lamp fitted. If you have this kind of fitting, you need special aluminium-backed lamps. They throw as much light (and consequently heat) out of the front of the lamp and less out of the back.

Ordinary lamps send more heat out of the rear of the lamp, thus overheating the lampholder. This can cause serious overheating and damage.

If you do not have fire-rated fittings, you may have cheap lampholders or insulation over the fittings or a combination.

As for the dimmers, it depends what kind of lamps they are switching...

 

[securespark]

This from the Aurora website re the dimmer:

•Suitable for control of dimmable compact fluorescent and LED lamps, dimmable electronic transformers, LED drivers, toroidal transformers and tungsten lamps Integrated trimming potentiometer allows CFL and LED lamps to be set at a minimum level to prevent them going out or flickering at the bottom of the dimmer range Leading edge phase control For use with resistive and inductive loads Integrated over-temperature protection fuse Module case ultrasonically sealed to reduce dimmer buzzing Smooth dimming operation from 0-100% light output May be fitted to most dimmer plates One or two way switching Complies with the latest Electrical Safety standard for dimmer switches EN 60669-2-1:2000 EMC compliance - EN 55015 1 Year guarantee

If the wrong load is on the dimmer, it could cause flickering and buzzing an premature failure.

 

[Robin0577]

Provided you can easily remove the transformers and get and the mains supply behind each fitting, then I'd be inclined to change the whole lot to LED units like these..

http://www.tlc-direct.co.uk/Products/LTFRD12DL.html

The initial cost will be quite high at 30 quid +vat per unit, plus you'll probably need to change any dimmers for trailing edge ones to but the energy saving will make it worthwhile eventually. How long that is will depend on how many hours use per day they get.

I have no connection with TLC by the way, I linked to these particular units because I've just fitted several in our reception area at work and found them to be brighter and have a better beam spread than the MR16s they replaced, while consuming 10.5w instead of 50. They claim to have a 50,000 hour lifespan, obviously (hopefully?) it will be some time before I can tell if that's true!

 

[canduit]

Sorry to say but consider the money and time and aggro you've spent with this set up. Seriously, there are many other options out there. If you're interested just ask and Im sure you'll get a lot of constructive ideas that don't have to cost the earth.

 

[RedTomato]

Your SELV lampholders are burning out.

Are they overheating?

One issue often overlooked is that of a fitting being fire-rated, and the fitting has the incorrect type of lamp fitted. If you have this kind of fitting, you need special aluminium-backed lamps. They throw as much light (and consequently heat) out of the front of the lamp and less out of the back.

Ordinary lamps send more heat out of the rear of the lamp, thus overheating the lampholder. This can cause serious overheating and damage.

If you do not have fire-rated fittings, you may have cheap lampholders or insulation over the fittings or a combination.

As for the dimmers, it depends what kind of lamps they are switching...

Thanks, you raised some good points. I've been changing my bulbs one by one (as they burn out) to Sylvania Cool-Fit - I presume this is the type of bulb you mean? Any other options to Sylvania cool-fit? They're the only ones I can find.

Way I see it is why pump 400w (8 downlighters) into the ceiling cavity when that could be going to heat up the room? Wife says won't it be too hot? I say when is it dark? In the evening. When does a room feel cold? In the evening. Win-win

Lampholders - standard cheap recessed ones - but new install, so should be fire-rated. Bathroom lights have been particularly bad. They're IP-rated but don't seem all that steam-proof - maybe the the steam from showers is affecting them?

Dimmers - seem to be at the right load, but the dimmers themselves are ****. Turn them down, light goes out, but dimmer is still passing current through (possibly as much as half one leccy told me). Means you think the lights are off, but your bill is going up.

Transformers are deffo dimmable ones, & the load seems to be right - not sure how much the bulbs use when low - are you suggesting the dimmers are hitting their minimum limits? Three of the dimmers have lost their top end - lights go off when dimmer on max, & come back on when dimmer is turned down a bit.

 

[RedTomato]

Sorry to say but consider the money and time and aggro you've spent with this set up. Seriously, there are many other options out there. If you're interested just ask and Im sure you'll get a lot of constructive ideas that don't have to cost the earth.

No need to apologise. You are right on all your points. I'm not wedded to this set-up - I just said to the six-gun leccy I wanted a nice lighting system that could be dimmable & this is the **** I end up with.

We asked the second sparky to change over the downstairs hall lights to LEDs a few months ago as we leave them on all the time & don't need them to be dimmable. Quite pleased with them so far, but not suitable for use in the rooms. ('warm white LEDs' but still colder white & non-dimmable).

Ideas welcome.