Protected circuit
Approved document B, Fire Safety, Volume 2, Buildings other than dwellinghouses (2019 edition), defines a protected circuit as:
| An electrical circuit that is protected against fire. |
Cabling should at least meet the requirements of PH 30 classification or an equivalent standard and should only pass through parts of the building in which fire risk is negligible.Protected circuits are required where it is critical that an electrical circuit continues to operate during a fire. This should include the use of sufficiently robust cables, careful selection of cable routes, and/or by the provision of physical protection in areas where cables may be susceptible to damage. Cable supports should generally be non-combustible and such that circuit integrity will not be reduced below that afforded by the cable.
Protected circuits should be separate from other circuits.
[edit] Related articles on Designing Buildings Wiki
- Amendment 3 BS 7671 Requirements for Electrical Installations IET Wiring Regulations.
- Approved document B.
- Approved document P.
- Approved documents.
- Articles by the Electrical Contractors' Association (ECA).
- Building regulations.
- Consumer unit.
- Electrical appliance.
- Electrical control systems.
- Electrical drawing.
- Electrical engineer.
- Fire.
- Glossary of electrical terms.
[edit] External references
- BS 5266-1.
- BS 5839-1.
- BS 7346-6.
- BS EN 50200:2006.
Featured articles and news
We're expanding our collaborative mission by launching DB Intelligence, an exclusive market research advisory panel. Built environment professionals can now get paid to share their expertise on industry trends, products and services.
Panel members receive direct financial incentives for participating in research projects like short surveys, 1-2-1 interviews and focus groups. Register today to shape the future of the construction sector.
Planning condition discharge in England and Wales
A brief exoplanation from a building compliance expert, with further links.
Overheating guidance and tools for building designers
Guidance for dealing with element of building fabric control that have increasing importance.
Shading for housing, a design guide
From the Good Homes Alliance and British Blind and Shutter Association.
UK Standard Skills Classification (SSC)
A shared framework for describing skills needs.
Social media ban consultation comes to close
CIOB urges UK Government to consider social media’s role in careers guidance in ban debate.
The latest of eight Skills England apprenticeship units
The addition of battery manufacturing welcomed by ECA with a warning about the risks of fast-tracked apprenticeship units.
Building Control Independent Panel final report
A precis of a key report led by Dame Hackitt with full recommendations and link to the government response.
Building Safety recap April, 2026
A short and longer run-through of the month, with links to further information and sources.
CIAT May 2026 briefing.
From medieval scribes to modern word art.
ECA welcomes crackdown on late payment and push for clean energy, whilst CIOB seek fixed cladding removal timeframes.
Cyber Security in the Built Environment
Protecting projects, data, and digital assets: A CIOB Academy TIS.
Managing competence in the built environment
ITFG publishes new industry guide on how to meet the ICC principles.
The UK's campaign to reduce noise pollution: Mythbusting, articles and topic guides.