WIRES AND CABLES by Y8AeAhA8

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									By: Arch’t. Babylyn Rodriguez - Ocampo
   The use of wire can be traced as far back as
    3000 B.C. when metal was hammered into
    sheets then cut into strips and again shaped to
    form wires.

   Drawing as a method of producing wire
    started in Europe in the 13th century. The
    process is characterized by having metal drawn
    into series of holes. The process is done until
    desired diameter is achieved.
   In 1831, Ichabod Crane, an American introduced
    drawing of wire as a manufacturing process by using
    the waterwheel to provide the mechanical power.

   The process he introduced has been adopted as a
    method for manufacturing until today.

   The use of wire as a practical material for conducting
    electricity had escalated especially with the invention
    of telegraph, telephone and other electrical equipment
    and devices.
   Wires are those electrical conductors which are
    No. 8AWG or smaller while cables are those
    larger than wires.

   They are either solid or stranded

   A single conductor number 14AWG, 12AWG,
    10AWG and 8AWG are called Wires

   STRANDED WIRE – consists of group of
    wires twisted to form a metallic string.
   CORD – A term given to an insulated wire.

   CABLES – electrical conductors larger than
    wires. A single number 6AWG to 0000 AWG is
    called cable
                  0 AWG = 1/0 AWG
                 00 AWG = 2/0 AWG
                 000 AWG = 3/0 AWG
                0000 AWG = 4/0 AWG
              Trade Name                    Type   Maximum      Location
                                                   Operating
                                                   Procedure
                                                      C-F

  Moisture and Heat Resistance Rubber       RHW     75 - 167   Dry and wet

              Thermoplastic                  T     60 – 140       Dry

    Moisture Resistant Thermoplastic        TW     60 – 140    Dry and wet


      Heat Resistant Thermoplastic          THHN   90 – 194       Dry

Moisture and Heat Resistant Thermoplastic    THW   75 – 167    Dry and wet
                                            THWN

 Moisture and Heat Resistant cross linked   XHHW   90 – 194    Dry and wet
    With Thermosetting Polyethylene
            Silicone Asbestos                SA    90 – 194       Dry

    Asbestos and Varnished Cambric          AVA    110 - 230      Dry
   Both have lower installation cost.

   Copper is preferred over aluminum in all
    preferences.

   Aluminum is lighter than copper, but forms an
    oxide causing poor conduction.

   Aluminum conductor is restricted to sizes not
    smaller than #AWG.
   Assembly of wires of           Used for residences
    plastic insulated bound         and re – wiring of
    together with a tape or         existing buildings.
    braid wrapped with a
    spiral wound
    interlocking strip of
    steel tape.

   Installed as a unit, with
    U – clamp or staples
    against walls, ceilings
    and columns.
   Can be pulled into place through existing
    spaces in back of plastered surfaces, under
    floor joists or between studding in walls.

   Provided with special couplings, box
    connectors and other fittings to interconnect BX
    with RSC’s.
   To carry large             Sizes vary from ¼ “
    amounts of current or       x4” / 5/16”x6”
    power require high -
    current carrying
    application.

   Carrying capacity of
    copper bus is
    1000A/sq.inches to
    safely carry 500
    Amperes.
    Bus is made from solid       Plug – In refers to a
    copper and assembled           design that allows
    in metal housing (             devices such as switches
    busduct ).                     and circuit breakers
                                   directly plugged into
   Bolted in connection           the busduct.
    with stiff metal housing
    installed with angles,
    bends, tap – offs and
    curves.
   Similar to busway
    except that it uses
    insulated cables
    rigidly mounted in
    open space frame.

   Carries higher
    ampacity in free air
    than in conduit rating.
   Allows the change in
    feeder length

   Allows a number of
    taps

   Sustain hours of
    operation

   Less energy rates
   An enclosed channel designed expressly
    for holding wires, cables, busbars with
    additional functions

   Either made of metal, plastic, or any
    insulating medium
   Conduits are circular raceways used to enclose
    wires and cables and are of metal or plastic
    (PVC)
   Flat Cable Assemblies

   Lighting Track

   Cable Tray

   Open Raceway
   FLAT CABLE                  -   Useful for small unit
    ASSEMBLIES                      heaters or single phase
-   Field constructed               light duty services

-   Consist of 2 – 4            -   Eliminates the necessity
    conductors                      of hard conduit / cable
                                    wiring.
-   Connection extend
    directly to the device or
    to an outlet box with
    receptacle for easy
    disconnection.
   LIGHTING TRACK
-   Factory assembles channel
    with conductors for 1 – 4
    circuits permanently
    installed in the track.

-   Power is taken from track by
    special tap – off devices that
    contact the track electrified
    conductors and carry power
    to the attached lighting
    fixture generally rated 20A
    unlike FC assemblies that is
    restricted to 120V.
   Continuous open              Cable Tray
    support for approved
    cables.

   Requires that cables be
    self protected or
    jacketed types.
                                 Open Raceway
   Free air rated cables,
    easy installation,
    maintenance and
    relatively low cost but
    bulky and require
    Three variations are:

1.   Conduit pipes

2.   Surface raceways

3.   Under - floor ducts
   Protect and enclose
    wiring from mechanical
    injury and corrosion

   Provide grounded
    metal enclosure for the
    wiring in order to avoid
    shock hazard

   Provide a system
    ground path
   Protection from fire hazard, overheating or arcing of
    the enclosed conductors

   Support the conductors

    Made from :
-    Hot Dip
    ( galvanized into molten zinc )
-    Enameled
    ( coated with corrosion – resistant enamel )
-    Sherardized
    ( coated with zinc dust )
-    Plastic covered

								
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