Low voltage
From Wikipedia, the free encyclopedia
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).
In the US, a number of less commonly used definitions are also used, which cover what is more commonly and internationally referred to as extra low voltage:
- An electromotive force rated 24 volts phase-to-phase nominal or less, supplied from a transformer, converter, or battery is called low voltage.[citation needed]
- Appliances and lights that operate at a lower voltage than line voltage are termed low voltage. These appliances or lamps require a transformer to reduce line voltage to usually 12 or 24 volts.[citation needed]
