Listed below are insulations that are currently used in medium voltage. For wire and cable products, the complete listing mark is located on a tag attached to the reel or smallest unit container. An electrical cable is an assembly of one or more wires running side by side or bundled, which is used to carry electric current a cable assembly is the composition of one or more electrical cables and their. Table iii c color of insulation for identification of wire sizes. Figure 3 shows a type useful for popular sizes of conductors 6 awg through 750 kcmil. Cable insulation materials the following materials are typically used for cable insulation. Among them all, cat5 and cat5e are most commonly used. Thermoplastic thermoplastic compounds are materials that go soft when heated and harden when cooled. For both cmp cable alternatives, the production of insulation resin fep and jacketing resin pvc, were each top contributors to three impact categories. These ul symbols may also be preceded by the letter. It is often found in cables meeting the ul standard 910 plenum cable flame test, deeming the cables suitable for use in a buildings space for air circulation, typically behind dropped ceilings or raised floors. While the terms wire and cable are often used interchangeably, a wire is one electrical conductor and cable is a group of wires, or conductors, encased in sheathing. Submarine cable generally consists of a lead sheathed cable and is usually armored. The insulation layer immediately surrounds and is fully bonded with the conductor shield.
Paper based insulation is the oldest type of power cable insulation and is still used mainly for high voltage cables. The test measures the insulation resistance between the phases andor between phase and ground. In some cases, a network will utilize only one type of cable, other networks will use a variety of cable types. Power and control cable insulation andor sheath materials insulation, inner or outer sheath of polyvinylchloride pvc y insulation made of cross linked polyethylene xlpe 2x inner or outer sheath. Types of conductors used in overhead power lines classification based upon insulation of the cable various insulating materials used in cable construction are rubber, paper, pvc, xlpe cross. C to 50c, 8 gauge meets j1128 rated 60v meets awg specifications copper conductor for maximum conductivity annealed stranded copper conductor fine stranded, annealed bare copper wire. This is the layer where various cable types differ most. This is one of our series of articles delving into component and material options for custom cable. The benefits of xlpe insulated cables eland cables. To evaluate a number of test results on the same piece of equipment, you. The capacitance and loss will be similar with 1 kv or 10kv applied to the cable. Thermoplastic compounds are materials that go soft when heated and harden when cooled. We can supply you with the right sizes, types, and quantities of product you. Types of wire and cable insulation allied wire and cable.
Page 812 explains the usual meaning of these nec type letters. Cable can be manufactured and installed in long lengths of 6500 feet, and even longer, which minimizes the number of manholes, splices and installation costs. The following materials are typically used for cable insulation. Find out what the markings on your power cable mean. Ethylene propylene rubber is a generic term for a wide range of polymers based on copolymers of ethylene and propylene.
The insulation shield encases the insulation and in some cases may be composed of the same semi conductive. Section 2 insulation materials and properties mp4 l. Insulated wire or cable consists of nonconductive material or some other kind of. Construction and building wireencompasses a wide variety of 300 and 600volt wire and cable including ul types thw, thw2, thwn, thwn2, thhn, tffn, tfn, rhh, rhw, rhw2, use, use2, thermostat wire, ser, seu, xhhw, xhhw2 and others.
A classification for an insulation that is extruded onto wire and then, when subject to heat and pressure, undergoes a. Three types of insulation materials are in frequent use today include. It is one of a number of rubber insulation materials. Types of breakdown dischargeinduced breakdown occurs when electrical discharges occur on the surface or in voids of electrical insulation. Includes reference chart to cross reference jacket types and uses. Attachment tape use on 12 30 cm intervals or as required by code or specification.
Flame spread and smoke developed ratings are of vital importance. H heater cable vw1 flame retardant ft2 flame retardant when only one o appears in a classification i. There are varieties of wires and cables as well as wire and cable insulations. Types of electrical wires and cables the home depot. The preceding insulations are typically those used for low voltage applications 2000v or less.
Sjeow, only the outer jacket material is oil resistant. Complete guide to major types of ethernet cables and their. Phase identification on nonshielded 6005000 v cables is accomplished by a. Table ii allowable shield and jacket materials for each basic type wire 99. Insulation resistance testing is a nondestructive test procedure. Pvc polyvinyl chloride is the most commonly used thermoplastic insulator for cables. Where a cable has both an inner and outer sheath, the class of sheathing material shall be identical except on fs types.
The polymeric forms of cable insulation are more susceptible to electrical discharge than impregnated paper and at the higher voltages, where the electrical stresses are high enough to promote discharge. Type itc instrumentation tray cable nec article 727 these types of cables are instrumentation cables and are available in shielded or unshielded constructions consisting of multiple single. Quick cable battery cable is available with red or black insulation, and features a colorcoded stripe to match with. Electric heat tracing label peelandstick label attaches to insulation vapor barrier. Cable designers guide how to specify cable insulated conductors specify quantity, gauge, stranding and insulation type for the conductors. There are five types of ethernet cables available in the market.
The strand and insulation shielding is normally an ex truded layer of semiconducting material. Properties of importance to electrical insulation ability include dielectric constant, resistivity, dielectric loss, and dielectric strength. Insulation material should be xlp or epr, except when paper insulation is justified because of its high resistance to, and. For that reason, most cables are named after their metallic shield e. Bs6883 general information british standard specification for elastomeric.
Both electrical and transmission cables make use of insulation to protect their enclosed conductors from temperature extremes, abrasion, currentsignal loss, and moisture. There are different types of a conductor as class 1. For the baseline cable, electricity generation was top contributor to three impact categories. Because electrical insulation will exhibit dynamic behavior during the course of your test. The paper insulation must be impregnated with a dielectric fluid e. We can supply you with the right sizes, types, and quantities of product you need to keep you on schedule and your management happy. Includes reference chart to cross reference jacket types. History of cable systems insulation history global 7 year v o l t a g e k v 1900 1925 1950 1975 2000 600 500 400 300 200 100 0 paper polymer type. Learn all about insulation materials and their defining characteristics. Within the three types of insulation, there are several unique varieties that bear consideration when determining the best insulation material for a specific application. Listed below are insulations that are currently used in medium voltage 2001v and above applications and high integrity, low voltage cable designs. The types of tests performed in the various phases can depend on the environment of the cable as well as the type of cable being tested.
Mainly in the cable industry, we use copper atc, abc and aluminum conductors for power cables. Xlpe is suitable for voltage ranges from low to extra high voltage, surpassing other insulation materials such as pvc, ethylene propylene rubber and silicone. Cable types, design, and associated insulation faults. Corona, or partial discharge, is characterized by small, local electrical discharges treeingelectrical results from partial discharge. The functional unit for each cable type is the insulation and jacketing used in a linear. There are several types of cable which are commonly used with lans. Two types of ul symbols ul in a circle or ul in parentheses may be found on the wire or cable itself. Finding the root cause of cable failures can lead to better maintenance practices and produce more reliable operation in the future. Electrical insulators or insulating bodies characterised by their insulating or dielectric material or form, including capacitor type. This insulation is used in a wide range of industries and applications. Thermoplastic insulation refers to the petroleumbased plastic material that softens when heated. If a cables insulation is perfect, the loss factor tan delta will change little as the applied voltage is increased.
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