Ofcourse, theres always cowboys. But hes asking on here for advice, and if hes given best practice for burial and does that, then whats the issue?
Is there though? How do you know any of those existing circuits were installed correctly, and werent lashed up by some clown? I'm no electrician, but having lived in a few houses, theres always been some "horrors" with the wiring that i've had to rectify.
Infact your pics show exactly that, none of those installations are new, and if you hadnt been looking for rats, you'd never have found the shallow buried cable, and if you'd been invited in to do a board swap or whatever on one of those installs its unlikely you'd have actually inspected the cable routing.
All I'm saying is speak to the electrician first as he is the person taking on responsibility for the job. Yes sure a decent set of pics will satisfy many sparks but many more will not like it, especially if they have encountered problems in the past.
No obviously one would have no idea what the existing circuits are like, however when working on existing circuits one would not be certifying they have 'designed and installed'.
Correct the first pic is an old old service, however we were not looking for rat holes, we were attempting to run a another cable and the rods were not arriving where expected as they found the hole and exited. What is not apparent is the undergrowth, when that was taken the area was a mass of weeds, mostly nettles and the rods took some searching for.
The second pic the duct was, believe it not, less than a month old. The ducts had been installed by the customer in preparation for some fairly extensive building works, and the splitcon was installed at the same time. when we surveyed that is all there was in the whole of the duct system. By the time we were on site working, the alarm company had added the white cable which we found while pulling a cable through the pit but not into that particular duct. By the time we were adding a cable to that duct, the draw rope had vanished and the water and SWA had been pulled in. We tried the vacuum cleaner to get a draw string in but there was no sign of a suck which was when we discovered the water Tee and the SWA branch off, oh and of course the bundle of bunched up draw rope.
So it was totally new and provided for the job we were doing but the depth in the ground was all over the place.
Another job we did was a simple 2.5mm² 3C SWA to an outbuilding. The customer got a 50mm duct installed by the block paving drive installers. it was great, the duct ran from under the ground floor of the house right under the CU to inside the brick outbuilding. the gap between the ends being a clear run now covered with block paving of about 15m. A 25m coil of SWA was purchased and Henry sucked for all he was worth, making the string appear quickly. A draw rope was soon pulled in and the SWA attached, the pull was surprisingly heavy but the leading end didn't emerge before the tail was about to disappear. They'd managed to install a little over 25m of duct which went in a ruddy great arc.
