Hmmm... does the color coding in the first picture remind you of anything?
Black, red, yellow...
The flags of Germany and Belgium?
Some of that wiring is scary. Even at 5kW I have a hard time believing that you could get much of a decent hot shower, unless the water is somehow pre-heated before reaching the shower.
Some of the older "instant" electric showers in use here (heating elements in the box on the wall, not in the showerhead!) are rated 6 to 7kW. It's reckoned that our water is delivered from the supply at a fairly constant temperature of about 50 degrees, and even with 7kW you can really only get a modest flow if you want the water to be anything but lukewarm.
