Sockets, leads and safety

This page explains published safety guidance in plain English. It is not advice about the wiring in your own home, and we are not electricians. Where it says to get a professional to check something, please do that.

A plug-in solar kit is unusual: it pushes electricity into the socket rather than drawing it out. That is why the wiring rules around it are stricter than for an ordinary appliance, and why this page is worth ten minutes before you buy.

The socket and the plug

• The socket must comply with BS 1363-2. In practice that means a standard, sound, three-pin UK wall socket.
• The kit’s plug must be BS 1363-1, moulded and non-rewireable, with partially insulated pins and a BS 1362 fuse of no more than 5A.
• It goes directly into the wall. Nothing between the plug and the socket.
• Choose a socket on a circuit with no lighting and no hardwired appliances such as a boiler or a cooker. To find out which circuit a socket is on, switch off one breaker at a time and see what goes off.

Why no extension lead?

The rules do not set out their reasoning, so we will not invent one. What we can say is what the specification requires: the kit plugs into a fixed socket, and its own plug must carry a printed warning against extension cables, multi-way adaptors and RCD adaptors. A multi-way lead also invites other appliances to share a connection that nobody has assessed, and it adds further plugs and contacts to a connection that carries power continuously in the direction ordinary domestic leads were never sold to carry it.

If the only sensible spot for the panels is nowhere near a socket, the answer is to have an electrician fit a socket where you need one, not to bridge the gap with a lead.

Outdoor sockets

Most kits live outside, so most people need an outdoor socket. Two figures are in circulation and it is worth knowing both:

• The product specification sets a minimum of IP55 for outdoor plugs and sockets.
• The Energy Saving Trust recommends at least IP65, and says an outdoor socket should be fitted by a qualified electrician.

IP55 is the floor. IP65 is the advice. For something that will sit in Manchester weather for fifteen years, pay the difference.

On building regulations, the position differs across the three nations and is easy to get wrong. In England, adding a socket to an existing circuit is not notifiable work, though installing a new circuit is. In Wales, outdoors counts as a special location and more work is notifiable. Scotland has a separate building standards system. Rather than rely on our summary, ask the electrician: a registered one will know what must be certified and will handle it.

Your fuse box

The specification says you should check your installation has modern residual current protection, meaning RCBOs, and is in good condition. If your home still runs on older fuse protection without RCBOs, it should be checked and, where necessary, upgraded by a professional electrician before you connect anything.

Here is the distinction that matters, and it catches people out. Rows of small switches that flick off when something trips are circuit breakers. They protect against overload and short circuits. They are not residual current protection, and a board made up entirely of them may have no earth leakage protection at all.

What you are looking for is a test button. Residual current devices, whether a shared RCD or individual RCBOs, carry a small button marked “T” or “Test”. Look at your fuse box without removing anything: lift the hinged flap if there is one, and see whether any device on the board has a test button.

• A test button on each individual breaker: those are RCBOs, which is what the specification asks for.
• One or two wider devices with a test button, with plain breakers after them: that is a shared RCD arrangement. See the note below.
• No test button anywhere: you probably have no residual current protection. Have an electrician assess the installation before you connect a kit.
• Old-style wire fuses in ceramic or plastic carriers that pull out: the installation should be checked and, where necessary, upgraded by a professional electrician.

If you cannot tell what you are looking at, that is not a failing. Ask an electrician. It is a five minute job for someone who does it daily.

There is a live technical question here that we will not paper over. The specification’s own footnote says ordinary MCBs with a shared upstream RCD “may also be acceptable, subject to verification through further testing now being undertaken by DESNZ”. So the position on older arrangements is not fully settled. If your consumer unit is a shared-RCD setup and you are unsure, get an electrician to look at it. That is cheap next to the alternative.

One more thing to raise with an electrician, which we cannot settle for you. Residual current devices come in different types, labelled AC, A, F and B, and they differ in the kinds of fault current they detect. You may see it said online that an older Type AC device must be replaced before a plug-in kit is connected.

We are not going to tell you that is true, and we are not going to tell you it is false. The detail sits in BS 7671, the wiring regulations, which is not published freely, so we have not been able to read it and we will not guess at a safety requirement. If your consumer unit is older, ask your electrician specifically about RCD type when you ask them to check the installation. It is a one-line question to someone who has the standard on their desk, and we would rather send you to them than print something we cannot stand behind.

Test your RCD every six months

Press the test button on the RCD, in the daytime, while the panels are generating. It should trip. If it does not, unplug the kit and call an electrician. Put a reminder in your phone for every six months, because nobody remembers otherwise.

Label the consumer unit

Your kit must come with a durable label to fix at or near the fuse box, showing that a plug-in solar device is connected. Put it on the day you set the kit up. It exists so that anyone working on your wiring in future, possibly in an emergency, knows there is a second source of electricity in the house.

Mounting it safely

A kit must be supplied with a proper mounting system. The specification is blunt about the alternatives: mounting that relies solely on cable ties, rope, string, adhesive tape or bungee cords is not allowed. Any attachment must be reversible and non-permanent.

• A panel is roughly two metres by one, and acts like a sail. Ground frames are weighted or pegged for a reason.
• Do not mount on a wooden fence unless a professional confirms it is safe. In England, fixing to a wooden fence, gate or wall also falls outside permitted development.
• Do not install on a building undergoing external wall remediation. The instructions have to warn you about this.
• Check what is behind a wall before you drill. Cables and pipes are usually exactly where you want your bracket.

When to call an electrician

• Your fuse box has old rewireable fuses, or you are not sure what you are looking at.
• You need a socket moved, added, or fitted outside.
• Your panels total more than 960W. The specification says to consider a professional assessment of your existing wiring at that point. Plenty of popular kits are above it: 1,000W, 1,030W, 1,050W and 1,260W kits are all on the market.
• Anything about the installation gives you pause. The whole point of a plug-in kit is that it is simple, and if yours is not simple, something is wrong.

The Energy Saving Trust points people to TrustMark to find a registered electrician.

Sources: the Plug-in Solar Device Interim Product Specification version 2 (16 July 2026), sections 4.1, 5.4, 5.5.1, 5.7, 8.2.3.1 and 8.3; Energy Saving Trust plug-in solar guidance, updated 24 September 2026; SI 2026 No. 848. Read 26 September 2026. This page explains published guidance. It is not a substitute for advice from a qualified electrician about your own home.