That picture looks familiar. We have similar installation here in Romania. Normally here there is no earth system just L/N. Neutral is supposed to be at earth potential, but usually isn't. Since most 3-core cable also comes with the standard green/yellow conductor, that gets used by the 'Electrician' for anything he likes, so it may be live. The colour codes are irrelevant – any electrical system is wired up using whatever colour cable the guy has – often all one colour. No ELTs, although we do have 'overload' trip switches, which usually don't.
We paid for a new mains connection to our newly built house (thats another story!), and the computer (E**L) fitted the latest hi-tech LCD display meter in a sealed box on a pole at the end of our drive (about 150 metres from the house). This box also contained a trip switch of some kind. After everything was connected up, I spent days trying to find out why this switch tripped out repeatedly. I could reset it, and by the time I had walked back to the house, it would have tripped again. Very worried, because the builder had buried some of the internal house cables under a concrete floor. Eventually I asked E**L to take a look – they told me it was fitted with the latest type of 'Brown-out' switch – if the voltage surged or dropped, then this switch would drop out. This is Romania – voltage can be anywhere between 200 and 260 volts AC, so eventually I persuaded them (bribed them) to remove the switch. Since then, all has been OK (relatively).
It is also not uncommon to find open bare wires connected to live mains – I have a second house on my property, and the incoming power arrives on bare aluminium wire to two plastic terminals (L/N) on the outside wall of the house. They are wrapped around the terminals, then simply buried in the plaster wall down to the meter (which once again, is a relatively hi-tech digital effort. I asked them to remove the meter (house not used), so they simply cut one of the wires out of the meter to a distribution box. Then I noticed the meter was still reading consumption of electriciy – about 10 kwH in two months. Now fed up, so I climbed up the wall wearing rubber boots and rubber gloves, and put an axe through the incoming cables. – I know, don't tell me, but desperation plays a major part in any dealing with companies in Romania, particularly a monopoly like E**L.
Needless to say, I have no faith in so-called 'professionals!'