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Many local codes permit NM cable inside walls or ceilings, and some codes allow it to be exposed in basements and garages. Underground feed cable has wires wrapped in solid plastic for watertight protection. The bonding wire is unique to AC cable and this allows the outer metal armor in conjunction with the bonding wire to be used as an equipment ground. Electrical cable encased in metal sheathing is often used in basements and other areas where the wire is not encased in a finished wall. It is handled differently than standard Romex® (non-metallic sheathed) cable. It is often used in fire-rated occupancies as an alternative to metallic conduit. Whether indoors or outdoors, proper wire and cable installation is of paramount importance – ensuring a smooth electricity supply, as well as passing electrical inspections.
I’m planning to rewire, and have already bought the MC cable for the job It’ll be a lot more work, but the result will be much safer than romex. Keep in mind that millions of homes are wired in NM cable and do just fine. Used only for exposed work in dry locations in buildings for industrial or commercial purposes.
The process used to cover the cable in its metal covering allows for better waterproofing and an overall tougher design. Exposed runs of cable, except as provided in 300.11, shall closely follow the surface of the building finish or of running boards. Exposed runs shall also be permitted to be installed on the underside of joists where supported at each joist and located so as not to be subject to physical damage. Conduit has one big advantage over ROMEX® wiring and that is flexibility. While ROMEX® is available in a number of sizes, the insulated wires are all white, black and red. With conduit, you can pull two yellow wires from a switch to a light fixture.
Herein, What Is The Difference Between Armored Cable And Mc Cable?
As home inspectors we see a lot of wiring in locations that need protection. Many common areas I find unprotected wiring are in closets and cabinets. Jim Dollard has an extensive background in codes and standards.
Romex is a type of conductor that has non-metal sheathing. They should be run through studs, on top of joists or trusses, and secured every six feet or so as well as within 12 inches of any fixtures. BX is safer than NM since the metal armor protects well against accidental penetrations. BX cable is grounded via its metal armor or internal green plastic-coated ground wire. Metal conduit once was used as a path for grounding; recent codes require a green-insulated ground wire. PVC conduit is cheaper than metal but not quite as strong.
The first number indicates the gauge of the wire.You choices are typically 10, 12, or 14 gauge. EMT is also called “thin-wall” conduit becauseit is thin and lightweight, especially compared to RMC. EMTis rigid but can be bent with a simple tool called a conduitbender. EMT is installed with couplings and fittings thatare secured with setscrew or compression-typefasteners.
Understanding Electrical Wire
If you are visiting our English version, and want to see definitions of Basic Armored Cable in other languages, please click the language menu on the right bottom. You will see meanings of Basic Armored Cable in many other languages such as Arabic, Danish, Dutch, Hindi, Japan, Korean, Greek, Italian, Vietnamese, etc. As mentioned above, BX is used as an acronym in text messages to represent Basic Armored Cable. This page is all about the acronym of BX and its meanings as Basic Armored Cable. Please note that Basic Armored Cable is not the only meaning of BX. There may be more than one definition of BX, so check it out on our dictionary for all meanings of BX one by one.
SWA Cable BS 6724 – which meets the requirements of British standard BS 6724 – has LSZH bedding and a black LSZH sheath. However, with the exception of electrical wires that run through rigid metal conduits, no other type of electrical cable has as strong https://simple-accounting.org/ an outer casing as does BX cable. Wires within the armor may display degradation of their rubber insulation. Romex cables are light and have a slippery coating that easily pulls through holes. BX is also known as Armor Clad or Flexible MetalConduit cable.
Common Electrical Conductor Types
If you have a query about the National Electrical Code , Jim will help you solve it. Questions can be sent to Answers are based on the 2014 NEC.
Older BX cables without an internal bonding strip arenot accepted by NEC. Differences between AC Cable and other types of cable include the limit on the number of phase conductors allowed. AC Cable is limited to four phases between the sizes of 14 AWG and 1 AWG. Additional differences include the use of a paper wrap on AC Cables whereas other cables use a polypropylene wrap or extrude directly over the conductors. Wiring in locations that are subject to “physical damage” will need protection. But what that protection is will depend on where the wires are installed and the environment of the installation.
The number of wires follows the wire-gauge on a cable. So, 10/3 would bx cable definition indicate the presence of 3 wires of 10-gauge within the cable.
Type MC cables are widely used in 600 volt and MV power, lighting and fixture whip control applications. They are permitted for use on services, feeders and branch circuits for power, lighting, control and signaling circuits in accordance with Article 330 and 725 of the NEC. When used with appropriate conductors, metal-clad cable and electrical metallic tubing havenearly identical uses but quite different workingcharacteristics. Because all-dielectric armored cable has nometallic components, there is no need to ground orbond the cable.
- However, active conductors cannot be green/yellow, green, yellow, light blue or black..
- Armored cable is a type of power-conducting cable that is covered in a metal sheath.
- Armored cable was first listed with Underwriters Laboratories Inc. in 1899 for the Sprague Electric Co. of New York.
- The metal is generally a long metal strip that winds around the cable; this gives the metal covering a corrugated, spring-like appearance.
- The use of FCC as applied to venues is prohibited in schools, residential occupancies and hospital buildings.
Metal Greenfield and plastic EMT tubing are flexible types of conduit. Poorly installed and maintained electrical cables are a common cause of electrical fires in homes. Many older homes contain wiring that is now considered obsolete or dangerous. InterNACHI inspectors should understand the basic distinctions between the different types of cable systems so that they can identify unsafe conditions. BX is also known as Armor Clad or Flexible Metal Conduit cable. BX is sheathed in a flexible metal spiral made either from aluminum or galvanized steel. BX provides all the advantages of NM cable plus some additional benefits.
Article 320 Armored Cable: Type Ac
A common stylecable that is rated for wet locations is a standard MCCable with a PVC jacket. View AFC’s full offering for ParkingDeck/Lot Cable today. “Knob and tube” was the most cost-effective wayto wire a home from about 1880 to the 1930s. It begangradually being phased out through the 1940s, displaced byelectrical cables that bundled hot and neutral, and eventuallyground, wires in a single flexible sleeve. Traditional Type MC cable is manufactured to ULStandard 1569.
- In most modern fixtures the neutral wire will be white and the hot wire is red or black.
- If the fiber-optic cable in a system needs extra protection, there is an alternative to using conduit or a bonded and grounded conductive cable, such as an all-dielectric armored cable.
- Different countries/regions have different cable color coding, and it is essential to know what is applicable in your region.
- Learn what these types of cables are, their differences and when to use MC versus Romex cabling in an installation below.
- Instrumentation Cable MC-HL Aluminum Armor The overall shield provides protection from external interference but not between group interference.
But because the outer sheathing is softer, less force is required to cut it. The different types of armor cable, mc cables and bx cable and there uses and or limitations such as wet locations. Staffers there said house wiring known by the brand name Romex can be dangerous if the insulation is gnawed by rodents or punctured by nails. They said the flexible insulation on the cable lacks the protection of conduit, the rigid metal tubes that encase wires.
Should Old Bx Cable Be Replaced?
Unless the specifics of the job or the electrical code demand that you use BX cable, your wiring project will go faster with NM, plastic-sheathed wiring. After you insert the cable into the tool’s groove, you turn the handle to cause the cutting wheel to cut away the metal sheathing. The tool is calibrated to cut the metal but stops short of touching the inner wires.
Wire gauge is the size of the wire, ampacity is how much electricity can flow through the wire and wattage is the load a wire can take, which is always mentioned on the appliances.. Insulated conductors shall be of a type listed in Table 310.4 or those identified for use in this cable.
Can You Bury Armored Cable?
Because all-dielectric armored cable has no metallic components, there is no need to ground or bond the cable. Teck 90-HL armoured and jacketed cablesare suitable for exposed or concealed wiring in wet or drylocations where cables are subject to the risk of mechanicaldamage and chemical abuse. It can be used in ventilated ornon-ventilated ladder type cable tray or troughs and fordirect burial for Class I, Div 2 locations. BX cable is heavy and its surface is corrugated, making it difficult to pull through the holes in studs. BX cable’s metal sheathing can be hard to cut without nicking or severing the inner wire. NM cable, too, presents the danger of nicking inner wires.
Bx = Basic Armored Cable
There is also FMC, called by the slang of “Greenfield” that comes without conductors installed. Knowing when and where a type of cabling system can and cannot be used is very important in electrical installations and is often a mark that a professional has not done the work.
Even with new projects, you still have the choice of using either metal-armored BX cable or plastic-sheathedNM cable. BX has a bonding strip to allow the casing to be a grounding conductor. MC is also availible as HFC cable which has a bonding strip as well as a full sized ground. This cable can be used in a patient care area or for an isloated ground circuit. If you cannot make this new circuit entirely within the walls then I strongly urge you to do a proper conduit job outside. MC cable has a full size ground wire the casing is not a grounding conductor.
Primary concerns are the relative conductivity of the armouring compared to the cores and reliability issues. That is Armored Cable, or commonly called BX which is a brand. Its from before the widespread use of modern polyethylene and synthetic plastics for insulation on wires. The copper wires in the BX cable are coated in rubber and wrapped in cloth. The issue over time is the rubber becomes dried out, brittle and crumbly.
