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I am in the process of buying a new bungalow. However I have noticed that there is a standard double 13a socket below the plumbing under the sink which is giving me cause for concern.
The builder advises it is fine as it has a cut out switch. There is no visible cut out switch so would appreciate any advice as to whether I should challenge this

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    In America we have a lot of plain sockets that are actually protected by a ground fault detector located elsewhere. This often confuses some, since they do not see the usual GFCI "test" and "reset" buttons. Millions of GFCIs have been installed needlessly because a realtor or home inspector told homeowners they had to. – Harper Oct 16 '17 at 10:40
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    Note that the presence of pipework is irrelevant in the standards. The presence of accessible water (taps/showers/sinks etc.) is what matters. And inside a cupboard under a sink is perfectly possible, following the rules – Chris H Oct 16 '17 at 14:44
  • Which country is this in? Exact rules (and conventions for e.g. location of protection devices) for this will vary by jurisdiction. – marcelm Oct 16 '17 at 15:32
  • @Harper In fact, conventional GFCI receptacles can support a piggyback connection to protect another regular outlet also (People who haven't installed one themselves might not know that, though). – Kaz Oct 16 '17 at 19:07
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I believe this is not uncommon. The circuit must be protected by an RCD (RCBO). There is usually a means of disconnecting or isolating the socket from above if the socket is inaccessible when appliances are installed.

However see NICEIC/ELECSA Guide to Electrical Work in the Kitchen

Electrical sockets or switches should be fitted at a safe distance (it is recommended at least 30cm horizontally) from a sink to avoid the chance of water coming into contact with electricity.

Sockets should also be easily accessible. If appliances such as fridges, dishwashers and washing machines are fitted under worktops, getting to sockets may be difficult. Ideally, these appliances should be controlled by a switched fuse connection unit mounted above the worktop where you can reach it easily.

All new sockets in a house require protection by an RCD (Residual Current Device)

The Consumer Units (Main Electrical Panel) in UK homes now typically have Dual-RCD protection. You could easily check this by inspection.

You can buy advanced socket testers that would allow you to verify correct RCD operation at the sockets under your sink.

If you want, I suspect there is nothing stopping you replacing the socket faceplate with one rated for external use (with a rainproof cover which can be closed over plug-cables) - some incorporate RCD protection. I suspect most electricians would regard this as pretty odd though.

If you search for advice you'll often see something like

Regulation 512.2.1, requires equipment to be of a design appropriate to the situation in which it is to be used or its mode of installation must take account of the conditions likely to be encountered.

I am not an electrician and do not have access to the 17th Edition. The above does not constitute advice from a qualified person. You can pay for an independent inspection and electrical installation condition report (EICR)

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If you're concerned about the socket being flooded in the wall, GFCI/RCD protecting it must be further upstream to be effective in that case. If it was visible nearby, that would be alarming, as it would be vulnerable to flooding itself, defeating the protection.

It's best practice to place safety devices as soon as possible (in the fusebox), so they protect not only the appliance, but the wall wiring as well. A socket with integrated RCD is merely a hack to retrofit RCD to a house with old wiring that can't support a "real" RCD in the fusebox. Rewiring old house is the best solution, but prohibitively expensive, that's how receptacle+RCD combos came into existence. Seeing one is not a sign of state-of-the-art wiring.

Nevertheless, the builder should explain you where all the circuit breakers are and how they work, in case one trips and you'll need to reset it. An RCD should be among them. Ask how the wiring is divided into circuits.

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    Hopefully, there are no fuses involved. – Brad Oct 16 '17 at 18:02
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    Yes and we replace fuses , reset circuit breakers. – Ed Beal Oct 16 '17 at 19:17
  • @Brad yeah, my bad, in my language it's same word. – Agent_L Oct 17 '17 at 15:16
  • How is a receptacle + RCD/GFCI not state-of-the-art? In my experience (US) a GFCI is 4-10x the cost of a receptacle, and they are commonly used as a cost-effective way to protect an entire circuit. The latest NEC codes (last ~5 years?) now require arc-fault breakers on many residential circuits, so there would only be regular receptacles visible inside a brand-new house. But given how recent that requirement is, a properly-placed (and wired) GFCI wouldn't concern me at all as "out of date", especially on a remodel. – brichins Oct 17 '17 at 16:01
  • @brichins State-of-the-art is: wiring compliant with new code + regular receptacles + RCD/GFCI in the fusebox. Refitting regular sockets to ones with integrated protection is second-best solution. It's a good thing still, but certainly it can't be called "state-of-the-art" is there are better and more advanced technologies available. Like arc-fault breakers. – Agent_L Oct 18 '17 at 8:20
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In the case of appliances which are under/by the sink, an outlet in this location makes perfect sense. As already mentioned, such an outlet normally requires a GFCI/RCD (which may be located 'upstream' in the same circuit), and is typically controlled by a wall switch above the counter (often in the same box with a switch for an over-sink light).

I know they aren't as common in the UK as here in the USA, but do you by any chance have a food disposal or dishwasher which is plugged into the outlet? If not, there may have been one previously which was taken out by the previous owner/occupant.

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