Search results
Results from the WOW.Com Content Network
In electric power distribution systems, a protective earth (PE) conductor is an essential part of the safety provided by the earthing system. Connection to ground also limits the build-up of static electricity when handling flammable products or electrostatic-sensitive devices.
Rural distribution is mostly above ground with utility poles, and suburban distribution is a mix. [1] Closer to the customer, a distribution transformer steps the primary distribution power down to a low-voltage secondary circuit, usually 120/240 V in the US for residential customers.
NEMA 1-15P (two-pole, no ground) and NEMA 5-15P (two-pole with ground pin) plugs are used on common domestic electrical equipment, and NEMA 5-15R is the standard 15-ampere electric receptacle (outlet) found in the United States, and under relevant national standards, in Canada (CSA C22.2 No. 42 [1]), Mexico (NMX-J-163-ANCE) and Japan (JIS C 8303).
The ground hole is officially D-shaped, although some round holes exist and many plugs have round ground pins. Both current-carrying blades on grounding plugs may be narrow, since the ground pin enforces polarity, but outlets have a wider opening for the neutral blade to prevent ungrounded polarized plugs from being put in backwards.
Each phase of the circuit is run in a separate grounded metal enclosure. The only fault possible is a phase-to-ground fault, since the enclosures are separated. This type of bus can be rated up to 50,000 amperes and up to hundreds of kilovolts (during normal service, not just for faults), but is not used for building wiring in the conventional ...
Hot is any line or neutral conductor (wire or otherwise) connected with an electrical system that has electric potential relative to electrical ground or line to neutral. Ground is a safety conductor with a low impedance path to earth. It is often called the "ground wire," or safety ground. It is either bare or has green insulation. [1]
The US National Electrical Code permitted the use of the supply neutral wire as the equipment enclosure connection to ground from 1947 to 1996 for ranges (including separate cooktops and ovens) and from 1953 to 1996 for clothes dryers, whether plug-in or permanently fixed, provided that the circuit originated in the main service panel. Normal ...
An external power supply, AC adapter or power brick, is a power supply located in the load's AC power cord that plugs into a wall outlet; a wall wart is an external supply integrated with the outlet plug itself. These are popular in consumer electronics because of their safety; the hazardous 120 or 240 volt main current is transformed down to a ...