Low voltage
According to Approved Document P - Electrical safety – Dwellings: Low voltage is, ‘a voltage exceeding extra-low voltage, but not exceeding 1,000 V ac or 1,500 V dc between conductors, or 600 V ac or 900 V dc between conductors and earth.’ Where extra-low voltage is, ‘A voltage not exceeding 50 V ac or 120 V ripple-free dc, whether between conductors or to earth.’
The Illustrated Guide to Electrical Building Services, Third Edition (BG 31/2017), by David Bleicher & Peter Tse, published by BSRIA in 2014, suggests that: ‘Low voltage is a term used to describe 400 V three-phase and 230 V single-phase supplies. These are nominal voltages - the actual voltage may vary up to 10%. The intake to buildings that have a low voltage supply is usually provided by the electricity supplier in the form of an underground cable that emerges at a suitable point within the building. The cable is connected directly to the electricity supplier’s cut-out. Also known as a service head, this is a fused unit that protects the supplier’s infrastructure.’
[edit] Related articles on Designing Buildings Wiki
Featured articles and news
London Build Fire and Security Expo
20-21 Nov and now with new Ambassador Programme..
The Scottish Building Safety Levy
Eight weeks of consultation closing on 18 November.
The grey, the brown and the golden rules of housing
shifting policies from the wild west of housing development.
Future proofing homes that are fit for purpose
Specification challenges and the role of plastic.
Thousands of new homes unlocked for brownfield sites
£68 million to 54 councils for neglected land into new homes.
Roof terraces and higher-risk buildings
Context, review, interpretation, case and guidance..
Sustainable Futures. Redefining Retrofit for Net Zero Living
More speakers confirmed for BSRIA Briefing 2024.
Architecture in Britain and Ireland, 1530 - 1830
Steven Brindle’s book is required reading.
Employment Rights Bill; making work pay
‘Biggest uplift in employment rights law since the 1970s’
Battle for Mill Road Free Library
Years of failures by the county and city councils.
The accolades that demonstrate and recognise outstanding achievement.
What is the Conference of the Parties ?
The who, where, what and when before no 29.
CIOB signs up to Green Skills At COP campaign
In preparation for COP29 on 11 November in Azerbaijan.
2024 ECA Industry Awards evening
Full list of electrical contractors scooping top prizes.
Briefing on the implications of the final Grenfell inquiry report
What it means for Architectural Technology professionals.
CIOB Art of Building photo contest 2024
International showcase for the very best photography of the built environment.