I think the biggest jaw dropper here is that in the UK, most domestic sparks are anti relay, based on the belief that they arc, stick and are a problem waiting to happen because they are mechanical. I posted in another thread about this - but it's simply not so, not anymore. I recently wanted to test a solenoid valves ability to open/close under a stressful cycle, so I lashed up a programmable delay timer and relay to control the solenoid, and set it to energise every 2nd second for 1 second, and then energise for 60 seconds every 5 minutes. It ran for about 10 hours a day every day for almost 2 months until in the end the valve seal split, some 1 million activations later. And guess what? the solenoid valve failed before the relay controlling it. More so, the relay itself in that arrangement was controlled by the relay switching of the delay timer, which in theory is not meant for that kind of cycle. That is how reliable relays are these days, and that is why the rest of he world doesn't think twice before using them. I would say under normal usage, they are going to have an operational lifespan at least on par with a MCB.
But in the UK, all that seems to advance when it comes to domestic electrical is the quality of the protection and the tightness of regulation. There has been no real evolution in how things are done since the grid was unified and people decided that separate protection for each circuit could be a useful idea. Speaking of which, do you see how many circuits that chalet has? A typical UK house is far larger and has half as many.. As with broadband, public transport, highways and mobile networks, everyone is an expert yet we get a below average result.
My personal take on why we like to keep things simpler...
More complexity = more time required when fault finding which in turn = greater cost. Also more complexity = greater cost at installation time.
There is a commonly held view that we are extortionists who charge way more than we should. There is also a lack of knowledge amongst the public about simple things (like the fact we're obliged to upgrade the earthing and bonding if it's sub par, even on small jobs... why is it going to take half a day? all I want is an extra socket next to that one!), this means when someone who gives a dam rocks up and quotes a lot more than Dangerous Dave, they're fighting a loosing battle because the potential client thinks you're just hiking prices and trying to rip them off.
To qualify that with an example... I was asked to quote for an extra outside socket. Simple enough, until you start looking at the existing supply arrangements for the existing outside socket that of course the client thinks you can just connect to. It was a spur from a spur (a single supplied by a 20A DP switch on a ring final that had been converted to a double - supplying washing machine and drier, so clearly no consideration given to the ratings of the switch, the cable or the socket outlet). I quoted to sort all of that out (in other words to bring the circuit I would be certifying back into compliance with the regs) and install the additional outside socket. Needless to say I didn't get the job (to put that into perspective, the top end was 6 hours and all in was around £250 which I think is reasonable, clearly not reasonable enough for ending up with a safer, regulations compliant job).
If I need relays, contactors or PLCs etc. to do a job, I'll use them, but thus far I've not come across any situations where they were needed, so using them just because you can isn't, in my opinion at least, a good idea mainly for the reasons I've outlined above (additional cost and complexity). But, whether you like it or not... relays, contactors etc.... they can fail and if you can get away without using them, you've just removed a potential point of failure which is beneficial for the client and beneficial for you.
Looking at that Italian board... first, it has one RCD for the whole board (there are regs that advise against this here - we aim to minimise risk and inconvenience in the event of a fault - that board, an earth fault on one circuit and it's all going out). Second, it's using double pole MCBs (so it actually only has 10 circuits - similar to the numbers you get here) but this is a reasonably good idea because it will disconnect neutral/earth faults (but there is a cost implication to this - bigger devices = bigger board = greater cost). Personally I'd rather have fewer circuits on RCBOs than lots of circuits on one RCD. But again, there are cost implications... more circuits = more costs. It's a balancing act.
As for the wiring methods... granted singles in conduit are nicer than twin and earth, but cost wise it's going to be more expensive as there is the cost of conduit, the time to install, time to pull the cables and the additional work terminating, and lets not forget building methods. It's bad enough trying to run twin and earth in some houses, I certainly wouldn't want to be running conduit in them.
I use ferrules where appropriate... flex (boilers, lights etc.), big ones on earthing conductors (sometimes) to keep them in reasonably good shape, larger cables (for the earths and neutrals in the CU) or for terminating in cooker/shower switches as you can get much better connections without damaging the cables. As for the chewed up ends... if everyone considered the next poor soul to work on an installation, they'd leave enough slack to allow for damaged cables to be redressed, unfortunately a lot of people don't and for some reason they seem averse to leaving the odd meter of slack here and there in cables, instead preferring them to be almost tight everywhere. So no slack = the inevitable chewed up cable ends.
It's easy to criticise something when it's not your regular job. You're operating in a specialist market which gives you an advantage in pricing as there is less competition. Domestic... we all know the problems in the domestic market... far too many unscrupulous gits who push the prices down and make it hard for those of us who give a dam to compete. So if it's a choice between using fancy gear because I can (and having a higher price for the job) or not because I don't need to (and having a more competitive price for the job)... which option do you think most people would take?
