Low voltage
From Wikipedia, the free encyclopedia
| IEC voltage range | AC | DC | defining risk |
|---|---|---|---|
| High voltage | > 1000 Vrms | > 1500 V | electrical arcing |
| Low voltage | 50–1000 Vrms | 120–1500 V | electrical shock |
| Extra-low voltage | < 50 Vrms | < 120 V | low risk |
Low voltage is an electrical engineering term that broadly identifies safety considerations of an electricity supply system based on the voltage used. While different definitions exist for the exact voltage range covered by "low voltage", the most commonly used ones include "mains voltage". "Low voltage" is characterised by carrying a substantial risk of electric shock, but only a minor risk of electric arcs through air. "Low voltage" is distinguished from:
- Extra low voltage – which carries a much reduced risk of electric shock
- High voltage – where electrical arcing is a substantial additional risk.
Commonly used definitions include:
- The International Electrotechnical Commission defines low voltage as any voltage in the range 50–1000 V AC or 120–1500 V DC.
- The United States 2005 National Electrical Code (NEC) defines low voltage as any voltage under 600 V (article 490.2).
- British Standard BS 7671:2008 defines low voltage as
- 50–1000 V AC or 120–1500 V ripple-free DC between conductors;
- 50–600 V AC or 120–900 V ripple-free DC between conductors and Earth.
