Fitting, and a socket outside where it's needed

Who can install one

The product specification is written for devices meant to be installed and operated by ordinary people, so you do not need an electrician to plug one in.

Anything that touches the house wiring is an electrician’s job. Testing or altering the electrical installation is work for a qualified electrician, and so is changing the overcurrent protection device on the final circuit if that is needed to connect. If you have any doubt about a socket, the instructions say to have an electrician inspect it. It is also worth telling your insurer.

The socket it plugs into

The inverter, the plug and the socket may sit indoors or outdoors. Outdoors, the socket must carry an IP55 rating or better. That is the part most homes do not already have, and it is the part we get priced for you.

• The plug is a BS 1363 type with a BS 1362 fuse and extra contact protection.
• DC connectors come from the manufacturer with the cables, and only matching pairs from the same family are used.
• Nobody pulls a DC connector apart under load, and the AC supply goes off first.

No extension leads

The specification bans extension cables, multi-way adaptors, RCD adaptors and travel adaptors, and it says so twice: once on the device marking and once in the instructions. That matters most in a garden, where an extension lead is the obvious shortcut.

A block like this is not a way to connect a panel

Multi-way blocks, adaptors and extension leads are all out. The device goes into a socket on the house, and where there is no socket in the right place, fitting one is the electrician’s job.

What one device is allowed to be

These are the limits from the product specification, and a kit that misses one of them is not in the approved class whatever the listing says.

• A compliant device tops out at 800 VA to the mains, with current no higher than 3.5 A.
• One inverter takes up to four PV modules, with no more than two of them in series in a string.
• The modules behind the inverter may add up to 2000 W. Panel capacity and output are not the same figure, and past 960 W of modules the specification advises a professional assessment.
• One device per final ring circuit, and one per household under the current network rules.
• Battery systems are outside the specification, so a kit sold with a battery is not covered by it.

Manufacturers have to register a device on the ENA Type Test Register and get confirmation that it was assessed as compliant before it goes on sale, so the register is the check to make before you buy anything.

Questions people ask