what is the standard voltage in the us
120 V
title: Mains electricity text: used in these countries is designed to accept any voltage within the specified range. In the United States and Canada, national standards specify that the nominal voltage at the source should be 120 V and allow a range of 114 V to 126 V (RMS) (−5% to +5%). Historically 110 V, 115 V and 117 V have been used at different times and places in North America. Mains power is sometimes spoken of as 110 V; however, 120 V is the nominal voltage. In 2000, Australia converted to 230 V as the nominal standard with a tolerance of +10%/−6%, this title: High voltage text: distinguish it from low voltage (50 to 1000 VAC or 120–1500 VDC) and extralow voltage (<50 VAC or <120 VDC) circuits. This is in the context of building wiring and the safety of electrical apparatus. In the United States 2011 National Electrical Code (NEC) is the standard regulating most electrical installations. There are no definitions relating to "high voltage". The NEC covers voltages 600 volts and less and that over 600 volts. The National Electrical Manufacturer's Association (NEMA) defines high voltage as over 100 to 230 kV. British Standard BS 7671:2008 defines "high voltage" as any voltage difference between conductors title: Electric power transmission text: to a higher voltage (115 kV to 765 kV AC, varying by the transmission system and by the country) for transmission over long distances. In the United States, power transmission is, variously, 230 kV to 500 kV, with less than 230 kV or more than 500 kV being local exceptions. For example, the Western System has two primary interchange voltages: 500 kV AC at 60 Hz, and ±500 kV (1,000 kV net) DC from North to South (U.S.-Canada border to U.S.-Mexico border). The 287.5 kV (Hoover to Los Angeles line, via Victorville) and 345 kV (APS line) being local standards, title: Mains electricity text: wires (like the ground wire or a person). When a ground fault is detected, the device quickly cuts off the circuit. Most of Europe, Africa, Asia, Australia, New Zealand and most of South America use a supply that is within 6% of 230 V. In the UK and Australia the nominal supply voltage is 230 V +10%/−6% to accommodate the fact that most supplies are in fact still 240 V. The United States uses a supply voltage of 120 volts +/- 6%. Japan, Taiwan, Saudi Arabia, North America, Central America and some parts of northern South America use a voltage title: Low voltage text: and commercial consumers. "Low voltage" in this context still presents a risk of electric shock, but only a minor risk of electric arcs through the air. In electrical power "distribution", the United States 2005 National Electrical Code (NEC) defines low (distribution system) voltage as 0 to 49 volts. Low distribution system voltage is covered by Article 725 of this code. The NFPA standard 79 article 6.4.1.1 defines "distribution" protected extralow voltage (PELV) as nominal voltage of 30 Vrms or 60 VDC ripple free for dry locations and 6 Vrms or 15 VDC in all other cases. UL standard 508A article