Out of interest, where did you get this information from?
I suspect loose connections AND cheap CU's is more the issue
there used to be stats available on each fire brigade area that broke domestic fires down into types, e.g kitchen fires, rubbish fires, accidental fires, malicious fires, electrical fires. Then they broke them down further, e.g, cigarettes dropped onto beds/couches, ashtrays emptied into bins, candles, unattended chip pans etc.The electrical fires were broken down into things like faulty fridges, overloaded extension leads, consumer units etc. so you could actually see the cause of a particular type of fire. Later on however they changed the way they display the stats and all electrical fires got lumped together under one group, so it isn't possible to break down the figures any more. I always found it rather convenient that they altered their stats just after the change of regs on CU's came in.
It always makes me laugh though when certain people do jobs, they connect it up and it works but no testing is done, yes it 'works' but it isn't necessarily safe. I remember going to one job, a fault on some sockets that the 'electrician' had installed, I had done previous work for this couple but they hadn't asked me to do this job as their builder had his own spark. It was a couple of floor sockets and he'd just put the cable under the tiles, no protection whatsoever. after connecting them up they kept tripping the breaker, a 32A on a radial in 2.5 t&e. in the end after uprating the breaker to a 50A and it still tripped, he announced that the fault was in the CU, it had obviously been installed wrongly!
Since it was me who had fitted it I was called back, the first thing I did was an IR test on his cable, dead short across all 3 wires! The customer asked what my MFT was for and I explained about testing, "oh, the other 'electrician' hadn't got one of those, he just wired it in and it kept going bang" she informed me.
I explained the fault was on his wiring and it would need ripping out and doing again, properly this time, she wasn't happy as it was all covered with expensive marble floor tiles. A couple of weeks later she rang me to tell me I was completely wrong about the floor, he'd been back and replaced the cable and hadn't done any damage, what he'd done was to remove the grout and adhesive from between the tiles, insert a new cable sideways and regrout the tiles, once that was done he'd connected it up and it worked, and he didn't need one of those 'tester things'.
It really made me laugh, even more so when after a few more months of his work they decided to sell the house and asked me to do a 'ticket' for them as the other guy couldn't, needless to say I declined to take on the work.
