North American mains plug and wiring. This is a 3-pin mains plug built to US NEMA 5-15 and Canadian CS22.2-42 standards. It is a Type B plug, designed to take alternating current (AC) at 60 Hertz, 15 amps and 125 volts. This is the most common grounded domestic plug in the USA, Canada and Mexico and parts of Central and South America. Other design differences include the pins, with the live (brass colour) and neutral (grey colour) pins being flat, while the earthed pin is U-shaped. The ground pin is also longer than the live and neutral pins, ensuring the device is earthed before the power is connected. The standard wiring colours (lower right) are black (live), green (ground) and white (neutral).