Search results
Results from the WOW.Com Content Network
In electrical power distribution, armoured cable usually means steel wire armoured cable (SWA) which is a hard-wearing power cable designed for the supply of mains electricity. It is one of a number of armoured electrical cables – which include 11 kV Cable and 33 kV Cable – and is found in underground systems, power networks and cable ducting.
The conduit methods were known to be of better quality, but cost significantly more than K&T. [2] In 1909, flexible armored cable cost about twice as much as K&T, and conduit cost about three times the price of K&T. [6] Knob and tube wiring persisted since it allowed owners to wire a building for electricity at lower cost.
Cables usually are secured with special fittings where they enter electrical apparatus; this may be a simple screw clamp for jacketed cables in a dry location, or a polymer-gasketed cable connector that mechanically engages the armour of an armoured cable and provides a water-resistant connection.
Outside plant cabling, whether copper or fiber, is generally installed as aerial cable between poles, in an underground conduit system, or by direct burial. [2] Hardware associated with the outside plant must be either protected from the elements (for example, distribution frames are generally protected by a street side cabinet) or constructed ...
Several other types of wiring systems are used for building wiring in the United States; these include corrugated metal armored cable, mineral-insulated cable, other types of power cable, and various types of electrical conduit. In industrial applications cables may be laid in cable trays. Cable type TC is especially intended for use in tray ...
Cables jacketing materials can be formulated to prevent fire spread [4] (see Mineral-insulated copper-clad cable). Alternately, fire spread amongst combustible cables can be prevented by the application of fire retardant coatings directly on the cable exterior, [5] or the fire threat can be isolated by the installation of boxes constructed of ...
Amendment No 2 : 2004 to BS 7671 : 2001 implements the cable core colours introduced in the revision of CENELEC Harmonization Document HD 308 S2: 2001 Identification of cores in cables and flexible cords and agrees generally with BS EN 60446 : 2000 Basic and safety principles for the man-machine interface, marking and identification.
A small metal, plastic or fiberglass junction box may form part of an electrical conduit or thermoplastic-sheathed cable (TPS) wiring system in a building. If designed for surface mounting, it is used mostly in ceilings, concrete or concealed behind an access panel—particularly in domestic or commercial buildings [2].