I have moved to a house which already has a wooden garden shed with an electrical supply. The installation comprises a fused spur off the house ring main, starting with a switched and fused unit, then an RCD. The cable (metal sheathed) is buried under a patio and feeds a double socket mounted on a fixed wooden board, into which is plugged a lamp.
The previous owner told me that the installation was done by a qualified electrician about 10 years ago. He explained that the spur was fused at 3A and only intended to supply a 100W light in the shed and a transformer for some low voltage garden lights. He explained that were I to plug a power tool into the socket it would blow the fuse and/or trip the RCD as it was not intended they were used for power tools.
As the shed is rotting in places I am contemplating replacing it with a plastic shed (these have a steel frame). My question is what do the regs say about this? Can I just fix the wooden board in the plastic shed and carry on using it like this? Do I need to earth the shed frame? Is the installation non-compliant? Like the previous owner I am not interested in power tools and just want a light in the shed.