Glossary
The terms and standards that recur across the other clauses, with what each one actually governs.
7.1Terms and standards
| Term | What it is |
|---|---|
apparent power | Measured in VA. The specification limit is 800 VA. Not the same quantity as the 800 W rated AC output in the instrument. |
BS 1363 | The British Standard for 13 A plugs and socket outlets. Its prohibition on using plugs to connect generating equipment is what blocked plug-in solar until 2026. |
BS 7671 | Requirements for Electrical Installations, the IET Wiring Regulations. Currently BS 7671:2018+A4:2026. A paid standard. |
BS EN 62109-1 | Safety of power converters for use in photovoltaic power systems. Clause 7.3.8 governs DC residual current. |
curtilage | The land attached to a dwelling. Relevant because permitted development covers buildings within it. |
DESNZ | Department for Energy Security and Net Zero. Publisher of the Interim Product Specification. |
DNO | Distribution Network Operator. Owns the local network. Not your energy supplier. Fourteen licence areas in Great Britain. |
ESQCR | Electricity Safety, Quality and Continuity Regulations 2002. Amended by SI 2026/848 for Great Britain. |
final ring circuit | The domestic ring main. The specification limits one device per final ring circuit; G98 is tighter at one per household. |
G98 | Engineering Recommendation for connecting fully type tested micro-generators up to 16 A per phase. Great Britain only. |
G98/NI | The separate Northern Ireland connection requirements. |
IP55 | Ingress protection rating. Required for a socket outlet mounted external to the premises. |
ordinary person | A person who is neither skilled nor instructed in electrical terms. The specification is written for installation by ordinary persons. |
permitted development | Development allowed without a planning application, subject to conditions. Plug-in solar relies on the microgeneration solar PV rights. |
PSSR | Plugs and Sockets etc. (Safety) Regulations 1994. Amended by SI 2026/848. |