Old wiring or fuse box?

[neiloneil]

Before I call an electrician, I want to get some idea about the cause of my problem.
In February my mother bought a pair of light fittings, both the same type, transformer mounted in the rose/hub and 5 arms coming out with 12v pin leg type bulbs. One of the units has been fine, but the other has burnt out on 2 occasions. I replaced it the first time and it was ok until a bulb blew, then the unit blew shortly after (same as the 1st time).
I have not put the new replacement up yet, as I am convinced it will not last very long.
The wiring and fuse box are as old as the house (1973), and I have convinced my mother she needs a new consumer distribution board installed. will this prevent the same fault happening or is it likely to be a wiring or earthing issue.

 

[RF Lighting]

More likely to be caused by cheap manufacturing processes in the chinese lighting factory.

 

[wingcoax]

As RF says, i have a customer who has had 4 units go after about a week
(B&@)










'

 

[neiloneil]

My mum got them from B&Q. last one we took back I had these 2 jobsworths at the return till ganging up on me, saying I'd fitted them wrong, that I could have burnt the house down, that I must get them fitted by a qualified electrician. that I had invalidated the warranty by fitting them myself. They said all the lighting equipment they sell must be fitted by qualified electricians. Are they right about this?
I am a practical man, no expert, but I can follow a simple wiring diagram. Or are they just making excuses for naff gear?
I thought it was more likely to be a wiring problem, but if you reckon it's common to have faulty units that makes sense too.

 

[flameport]

saying I'd fitted them wrong, that I could have burnt the house down, that I must get them fitted by a qualified electrician. that I had invalidated the warranty by fitting them myself. They said all the lighting equipment they sell must be fitted by qualified electricians.

All lies.

If there was something wrong with the wiring or supply to the house, all of the lights and appliances would be affected.

 

[neiloneil]

I can't take a photo ,as its been returned.
Inside the unit was charred. nowhere close to the connections I had made.

 

[bernardgreen]

Some of these imports are designed to be manufactured as cheaply as possible so the initial design is compromised. Then the manufacturing of this poorly designed product is made as cheap as possible and one of the ways to reduce costs and increase yield is to reduce or eliminate quality control checks.

Add to that the greed and other adverse motives of managers in both the factories and the sub-contract sweat shops used to assemble the units and the reasons for high failure rates becomes known.

Rant over.

 

[Space cat]

transformer mounted in the rose/hub and 5 arms coming out with 12v pin leg type bulbs

It's rare to find a real transformer these days. That thing in the hub will most likely be a switch-mode power supply; common name "electronic transformer". (Hint: a real transformer will be heavy) Some of them are cheap and nasty and they don't last long. Rewiring the house won't help.

I suspect you've just been unlucky twice - or should I say you've been lucky to get one good one!

 

[dave2506]

My mum got them from B&Q. last one we took back I had these 2 jobsworths at the return till ganging up on me, saying I'd fitted them wrong, that I could have burnt the house down, that I must get them fitted by a qualified electrician. that I had invalidated the warranty by fitting them myself. They said all the lighting equipment they sell must be fitted by qualified electricians. Are they right about this?
I am a practical man, no expert, but I can follow a simple wiring diagram. Or are they just making excuses for naff gear?
I thought it was more likely to be a wiring problem, but if you reckon it's common to have faulty units that makes sense too.

I find this really annoying mate and I'm sorry that you had to endure it. Next time ask them to back up their nonsense with the supporting legislation and their Electrician qualifications to support their advice.

Whilst I know not all on these forums agree, this shop is useful for buying the majority of DIY supplies and equipment. I would not, in a million years, ask for their advice though - other than to ask where a particular product is and sometimes then they struggle.

Sorry this is not particularly helpful for your original question but I thought you might appreciate the rant of someone who shares your frustration

 

[bernardgreen]

That thing in the hub will most likely be a switch-mode power supply; common name "electronic transformer".

Sir, you are too generous and excessively polite to apply the name switched mode power supply to these items.

The "unit" in a cheap 12 volt lamp handed to me recently produced a chopped mains voltage waveform to the lamp. Very narrow pulses so the overall average was about 12 volts but with pulses as high as the peak AC voltage as seen on the oscilloscope.

 

[ban-all-sheds]

There is hardly anything in the world that some man cannot make a little worse and sell a little cheaper, and the people who consider price only are this man's lawful prey.

 

[plugwash]

or unlawful in some cases. I'm fairly sure there is lots of cheap **** coming out of china marked with approvals that it doesn't comply with the requirements for.

 

[bernardgreen]

Falsified certificates of compliance have been found attached to consignments of goods from there.

The only thing that should be made in china is good quality crockery and chamber pots

 

[Space cat]

The "unit" in a cheap 12 volt lamp handed to me recently produced a chopped mains voltage waveform to the lamp. Very narrow pulses so the overall average was about 12 volts but with pulses as high as the peak AC voltage as seen on the oscilloscope.

Ouch!!!

And it goes without saying that there'll be no isolation either.

 

[bernardgreen]

There was no isolation, all there was on the PCB was a mosfet controlled by what appeared to be a 555 timer chip and couple of components to create a crude supply for the 555. One side of the mains straight to the mosfet and on to the lamp.