Search results
Results from the WOW.Com Content Network
A distribution board (also known as panelboard, circuit breaker panel, breaker panel, electric panel, fuse box or DB box) is a component of an electricity supply system that divides an electrical power feed into subsidiary circuits while providing a protective fuse or circuit breaker for each circuit in a common enclosure.
A plugboard or control panel (the term used depends on the application area) is an array of jacks or sockets (often called hubs) into which patch cords can be inserted to complete an electrical circuit. Control panels are sometimes used to direct the operation of unit record equipment, cipher machines, and early computers. The array of holes is ...
Revised standards for wire materials and wiring devices (such as the CO/ALR "copper-aluminium-revised" designation) were developed to reduce these problems. While larger sizes are still used to feed power to electrical panels and large devices, aluminium wiring for residential use has acquired a poor reputation and has fallen out of favour.
NEMA 5-20R outlets, which are similar to type B but have a T-shaped neutral slot, are sometimes used for higher current 120 V equipment (up to 20 A). U.S. Virgin Islands: A B NEMA 1-15P NEMA 5-15P 110 V 190 V 60 Hz Uruguay: C, F, I, L 230 V 400 V 50 Hz Type I was the main standard until the 1990s, and still appears in old installations.
Trunk cables may terminate on the same MDF or on a separate trunk main distribution frame (TMDF). Like other distribution frames the MDF provides flexibility in assigning facilities, at lower cost and higher capacity than a patch panel. The most common kind of large MDF is a long steel rack accessible from both sides.
Telephone signals do not use a separate earth ground wire, but some urban exchanges have about 250,000 wires on their MDF. Installing and rewiring these jumpers is a labour-intensive task, leading to attempts in the industry to devise so-called active distribution frames or Automated Main Distribution Frames. The principal issues which stand in ...
It is an assembly of one or more panels, each of which contains switching devices for the protection and control of circuits fed from the switchboard. Several manufacturers make switchboards used in industry, commercial buildings, telecommunication facilities, oil and gas plants, data centers, health care, and other buildings, and onboard large ...
Per UL Standard ANSI/UL 498, a receptacle (any color) with an orange triangle, is an isolated ground (IG) device, where the grounding pin of the receptacle is connected to ground independently of the frame of the receptacle and wiring outlet box. This is also a requirement of the National Electrical Code (NFPA 70), Article 406.