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A ring final circuit (often called incorrectly a ring-main) is defined by the power sockets being connected in a daisy chain arrangement which allows load current to be shared by two cables rather than one. You must not break the link...

OK, that is a ring final circuit. You can move the socket but keep the wiring the same or it may be easier to leave the lower socket where it is and run a spur from it using a single t&e 2.5mm CSA cable. EDIT, whatever you do, always keep the link between the two sockets since removing it...

Can you post a picture of the back of the dimmer?

I am assuming that by 1way and 2way you mean L1 and L2. If you toggle the other two-way switch or one of the intermediates then L2 will change from 50VAC to 240VAC. The 50VAC that you measure is most likely a potential difference (a voltage) between neutral (via the transformers)...

This sounds like they are all part of a ring final circuit which, if true, is absolutely fine. Are all the cables Twin & Earth 2.5mm CSA? To be sure of the cable size and the ring theory, can you post some pictures?

No I can't either, at least not a real world example. It is just that am "sensitised" (as you will know from previous posts) to anything that is connected to earth where there is no practical risk of it becoming live. I tend to evaluate (for better or for worse) the risk of the item becoming...

Yes an outdoor experience is what I was thinking though I have to say that other than PC PSUs some AV/TV equipment I have not noticed PELV very often if at all.

Yes, just looked that up. the acronym "SELV" is defined by the IEC as having (at least) the following characteristics: -maximum output 50VAC/(120VDC ripple free) -protective separation between primary/secondary winding/circuits. -no return path via ground/earth -at least a specified...

Yes, the transformer would be continuously rated for the SC current. They are often "higher impedance" transformers since the ohmic properties of the secondary winding material is designed/selected to aid in current limiting (that is in smaller transformers) There is of course a trade-off when...

Exactly. I believe (will confirm tomorrow) SELV does (by design criteria) limit the output voltage to 50VAC and provide safe isolation between primary and secondary. Interestingly in a PELV design the earth is connected to the secondary (more interestingly on TN-C-S supplies)

non-inherently would have some sort of thermal or other cutout to prevent significant heat rise under SC conditions (would open circuit the secondary and sometimes, double pole, the primary) Inherently would allow for temperature rise within the transformer design for smaller transformers...

Keep in mind that you may need help/advice from the forum in the future. I read your post as unhelpful at best and possibly rude. If I can read it that way then others are likely to as well. It is sometimes worth remembering why you signed up? Was it to be helpful and occasionally get help?

If you only have single phase requirements then absolutely only a single phase sub-main. If you were installing a three phase oven in one outbuilding then it would probably make sense to run a 3Ph&N sub-main only to that outbuilding, run the oven on 3ph&N and sockets/lights from only one of the...

If the bathroom fan was not a replacement, that is if a new circuit was installed then that would have been notifiable. However, if in general your electrical installation is in good order, I really do not think there will be an issue. You have certificates and a compliance document for the...

That is more or less a 20amp three phase supply which could be useful for a 3ph 3 wire(without neutral) or 3ph 4 wire(with neutral) appliance/machine but not much use for single phase applications in the domestic world.

Not if you are actually talking max CCC per phase. In such a case a single phase conductor supplying a load requiring say 30 amps would be no bigger than the L1 (or L2 or L3) conductor supplying 30 amps per phase. True that if you just look at the load then a machine/appliance with a total...

If the work was not notifiable then you would not receive a compliance certificate. What was the work?

Quite common practice is to feed each phase & N sub-main (after the meter) into a 3Ph&N switchfuse then SWA (4 core) submain to a consumer unit for final circuit connection. Henley blocks after the meter to allow for connections into the switch fuse boxes. EDIT, wait did you mean single...

Typically one of the following reasons: 1) low water flow rate (blocked/partially blocked spray head or low water pressure) 2) heater element covered in scale (causing overheating) 3) thermal cut out failed (usually resets on its own) If the problem is not 1) then it may be time for...