Connect the cable ends to a dry nitrogen or dry air supply using hoses, valves, fittings, and flow regulators as shown in Figure 8. If the coefficient handboko friction were 0. Installation and Testing 9. Several important mechanical and chemical characteristics include compression cut resistance, low temperature brittleness, resistance to the base oils used in filling gels, adequate tensile and elongation properties, and acceptable long-term aging characteristics.
The significance of conducting DC High Voltage tests on nonshielded, nonmetallic-sheathed cable informatuon dependent upon the environment in which it is installed because the characteristics of the return circuits are unknown.
This type of buffer provides excellent protection against bending and offers better crush resistance than does a loose buffer. In some instances it is desirable to use a grip over the outer covering in addition to the conductor connection to prevent any slippage of one with respect to the other. The sequence consists of six basic colors, then a repeat of the colors with a colored band or tracer.
It is revised on a regular three year schedule. The VSWR indicates the quality of the match. Tevhnical reels must be stored outside they should be supported off the ground and covered with a suitable weatherproof material. The diameters according to the AWG are defined as follows: Various core diameters are available to permit the most efficient coupling of light from commercially available light sources, such as LEDs or laser diodes.
Type T Copper vs Constantan is used for service in oxidizing, inert or reducing atmospheres or in a vacuum. These properties make TPE jackets an excellent choice for use in control cables that are dragged around or frequently moved. The ratio of received bits that are in error, relative to a specific number of bits received; usually expressed as a number referenced to a power of After that time, DC testing is not recommended.
FEP — Fluorinated ethylene propylene. When properly grounded connected to the associated electronic equipment, the shield acts as a barrier to incoming as well as outgoing EMI.
It offers high performance though it is large in size and cumbersome to handle. A grounding conductor is required in the electrical cord attached to appliances. Such strength members provide tensile load properties similar to electronic cables and, in some cases, are used as temperature stabilization elements. Jacket As with conventional metallic cables, the jacket protects the core from the external environment.
With optical fibers, however, the selection of materials is influenced by the fact that the thermal coefficient of expansion of glass is significantly lower than that of the metal or plastic used in the cable structure. Installation Normal cable loads sustained during installation or environmental movements first stress the strength members without transferring the stress to the optical fibers. If the load is increased, the fiber may ultimately be placed in a tensile stress state.
This level of stress may cause microbending losses which result in attenuation increase and possibly fatigue effects. A summary of applicable UL Standards, listings and markings is shown in Table 6. Note that, in some cases, the tray rating is an optional marking and is not an inherent part of the listing. The following sections provide information on some of the most frequently requested electrical parameters.
Table 7. The multiple conductor column in the table above covers the following conditions: a Single conductor cable; two or three cables in the same metallic conduit. For larger conductor sizes the shortcircuited sheath losses increase rapidly and the table above does not apply. The table represents maximum AC losses for the conditions outlined. To obtain values for other circuits, multiply by 1. The short circuit current is the maximum allowable current that the cable can withstand without damage.
The maximum allowable short circuit current for copper and aluminum conductors can be determined with the aid of Figures 7. Ampacity equals the 60 Hertz ampacity multiplied by the derating factor.
To use the current capacity chart Figure 7. Next, find the current value on the chart for the proper temperature rise temperature rating minus ambient temperature and conductor size. To calculate the maximum current rating per conductor, multiply the chart value by the appropriate conductor factor. Current values are in RMS amperes and are valid for copper conductors only. Note: Current ratings are intended as general guidelines for low power, electronic communications and control applications.
Figure 7. Because so many external conditions affect ampacity, tables covering all situations are not possible. However, tables covering many common situations are available.
BIL ratings for various system voltage ratings are shown below: Table 7. The information has been obtained from many sources and covers some of the major considerations when installing and testing power, control, instrumentation, fiber and communication cable. This prevents loosening of the cable turns which may cause problems during installation. If the roll direction is not indicated, roll the reel in the same direction it was turned when the cable was wound onto the reel.
Cable reels should only be lifted by forklift trucks from the sides and only if forks are long enough to cradle both flanges. Steel lifting bars of a suitable diameter and length should be used when lifting cable reels by crane or other overhead lifting devices. With heavy reels or reels that may be unbalanced the use of a lifting yoke is recommended to prevent reels from slipping or tipping during lifting.
If reels must be stored outside they should be supported off the ground and covered with a suitable weatherproof material. When cable lengths are cut from a master cable reel, all exposed cable ends should be resealed with plastic weatherproof caps or tape to prevent the entrance of moisture.
For installation in other types of conduits or for installation of compact stranded conductors, refer to Tables C1 through C12 in Appendix C of the NEC. Table 8. Trade Size In. Total Area Sq. Referring to 4 the table, minimum conduit size would be 4 inches. The method used depends on the anticipated maximum pulling tension in each case. When pulls are relatively light a basket-weave grip is often used. Heavier pulls usually require connecting directly to the conductor either by means of pulling eyes or by forming a loop with the conductor itself.
In some instances it is desirable to use a grip over the outer covering in addition to the conductor connection to prevent any slippage of one with respect to the other.
Nonmetallic Sheathed Cables The smaller sizes of nonmetallic sheathed cables are usually gripped directly by the conductors by forming them into a loop to which the pull wire or rope can be attached.
The insulation on each conductor is removed before the loop is formed. Larger sizes are more easily handled by applying a pulling grip over the cable or cables provided the pull is not too severe. If more than one cable is involved the ends should be bound together with electrical tape before applying the grip overall. Long, hard pulls will necessitate the use of pulling eyes. Lead-Sheathed Cables Pulling eyes for lead-sheathed cables can be applied either at the factory or in the field.
They often must be wiped to the lead sheath to prevent the entrance of moisture. For shorter pulls a basket-weave grip may be applied over the lead sheath or over the jacket if one is present over the lead sheath. Interlocked Armor Cables When pulling interlocked armor cable it is necessary to grip both the armor and the conductors.
This can be accomplished in a number of ways. One method requires that a portion of the armor be removed. Electrical tape is then applied over the armor and down over the conductors and a long basket-weave grip is applied such that it grips both the armor and the conductors. Another method requires that two holes be drilled through the cable armor and conductors at right angles to each other and a loop formed by passing steel wires through the holes and out over the end of the cable.
A third approach is to use a pulling eye and a grip together, the grip being applied over the armor to prevent it from slipping back. This latter approach provides the greatest strength. Preassembled Aerial Cable This type of cable should always be gripped by the messenger which is usually attached to a pulling swivel. In addition, a basket grip should be applied over the conductors to prevent any slippage and to facilitate guiding the conductors through the pulleys.
When a grip is applied over nonmetallic sheathed cables, the pulling force should be limited to 1, pounds provided this is not in excess of the force calculated above using the 0. The above limits are maximum values which should not be exceeded. However, it is possible to damage cables while applying lower tensions if, for example, there are sharp projections in a poorly constructed duct bank, or if an interlocked armor cable is pulled around too small a sheave.
Every installation detail cannot be covered here but staying within the above tension limits will help assure a successful installation. Clearance refers to the distance between the uppermost cable in the conduit and the inner top of the conduit. When calculating clearance, ensure all cable diameters are equal. Use the triplexed configuration formula if you are in doubt. The cables may be of single or multiple conductor construction. This usually occurs when cables are being pulled around bends or when cables twist.
A value of 1. Since there are manufacturing tolerances on cable, the actual overall diameter should be measured prior to computing jam ratio. The grease and oil type lubricants used on lead sheathed cables should not be used on nonmetallic sheathed cables. There are a number of commercially available wire pulling compounds many of which are UL Listed that are suitable for use with polymer jacketed cables. They usually consist of soap, talc, mica or the like, and are designed to have no deleterious effect on the cable.
Graphite and other electrically conducting lubricants should not be used on nonshielded cables rated 2kV and above. These materials can lead to tracking of the cable jacket. Apply plastic or rubber tape to help protect against invisible damage if the cable will be subjected to immersion or rain. This is particularly important if there will be a delay of some time between the pulling operation and splicing and terminating. Avoid sharp bends in the cable by using one 3-sheave pulley at degree bends and two 3-sheave pulleys at degree bends.
Do not release the tension on the messenger until it is secured to poles on both ends. These recommendations may be modified if experience and more exact information so indicate. With pulling eye attached to copper conductors, the maximum pulling tension in pounds should not exceed 0.
With pulling eye attached to aluminum conductors, the maximum pulling tension in pounds should not exceed 0. If the coefficient of friction were 1. If the coefficient of friction were 0. The primary function of a pulling lubricant is to reduce the tension on the cable as it is installed in a duct.
The quantity of lubricant required depends on various factors: The pull length, the condition and size of the conduit, and the difficulty of the pull. Portable Cables The minimum bending radius for portable cables during installation and handling in service is six times the cable diameter for cables rated volts and less.
For cables rated over volts use eight times the cable diameter. For flat twin cables, the minor diameter is used to determine the bending radius. Fiber Optic Cables Minimum bending radius for fiber optic cable is ten times the cable diameter for multimode and 20 times the cable diameter for single mode.
Figure 8. Arrange multiple blocks if necessary to maintain minimum bending radii whenever cable is deflected. For pulling around bends, use conveyor sheave assemblies of the appropriate radius.
The pulleys must be positioned to ensure that the effective curvature is smooth and deflected evenly at each pulley. Never allow a polygon curvature to occur as shown. The fit of the pulley around the cable is also important when the pulling tension is high for example, pulleys at the top of a vertical drop. Remember to use the radius of the surface over which the cable is bent, not the outside flange diameter of the pulley. All tests made after cable installation and during the guarantee period should be made in accordance with applicable specifications.
All safety precautions must be observed during testing at high voltage. Accessory equipment is necessary to safely conduct high voltage tests such as safety barriers, rubber gloves and nonconducting hard hats.
Consult appropriate safety officer. Some equipment will take longer to reach the maximum test voltage because of the amount of charging current. Allow sufficient time at each step for the leakage current to stabilize.
Normally this requires only a few seconds unless cable circuits of high capacitance are involved. Record leakage current at each step. Allow the residual voltage on the circuit to decay then ground the conductor just tested. Maintain solid grounds after the test on the cable for at least 4 times the duration of the test. It is a good safety practice to maintain these grounds longer and while reconnecting circuit components.
Proof Testing—At any time during the period of guarantee the cable circuit may be removed from service and tested at a reduced voltage normally 65 percent of the original acceptance value for 5 consecutive minutes. Record the leakage current at one minute intervals for the duration of the test. A constant or decreasing leakage current with respect to time at maximum test voltage is the usual acceptance criterion for DC hipot testing.
High potential testing is a tool for determining insulation resistance at high voltages. IR in general has little or no direct relationship to breakdown strength. The significance of conducting DC High Voltage tests on nonshielded, nonmetallic-sheathed cable is dependent upon the environment in which it is installed because the characteristics of the return circuits are unknown.
The environment must be carefully considered or test results may not be significant. In fact these tests can result in damage to the cable insulation. Humidity, condensation or actual precipitation on the surface of a cable termination can increase the leakage current by several orders of magnitude.
Humidity also increases the termination leakage current, which is included in the total leakage current. Wind prevents the accumulation of space charges at all bare energized terminals. This results in an increase of corona. It is desirable to reduce or eliminate corona current at the bare metal extremities of cable or terminations. This may be accomplished by covering these areas with plastic envelopes, plastic or glass containers, plastic wrap e.
Routine periodic DC maintenance testing of cable for the evaluation of the insulation strength is not a common practice. Some power cable users have adopted a program of testing circuits during planned outages, preferring possible breakdowns during testing rather than experiencing a service outage. It is nearly impossible to recommend test voltage values for maintenance. An arbitrary test voltage level could break down a cable circuit that would otherwise render long trouble-free service at normal operating AC voltage.
One advantage of DC high voltage testing is that it can detect conducting particles left on the creepage surface during splicing or termination. Test equipment should be supplied from a stable, constant voltage source. Do not use the same source which is supplying arc welders or other equipment causing line voltage fluctuations.
The output voltage of the test set must be filtered and regulated. Consider using a portable motor driven alternator to energize the test set. A proof test can be made during the guarantee period. Maintenance testing is not recommended. After that time, DC testing is not recommended. These units are portable, commercially available devices which can be used in the field to locate some types of conductor breaks or shorts.
Connected to the end of a cable, the device functions much like radar, sending out low voltage pulses which travel the length of the cable and echo back when an open, short, or tap is encountered. However, TDRs are only capable of locating breaks or shorts having an impedance different than that of the cable.
For most cables, this includes shorts having a resistance of less than a few ohms and opens having a resistance greater than several hundred ohms. Splices, taps, etc. Nevertheless, the method is nondestructive and is used successfully on faults having characteristics within the capabilities of the method. Low voltage IR tests are particularly useful in detecting shorts and indicating grossly deteriorated insulation on volt rated cables. An inherent limitation of low voltage IR tests is their interpretation.
The readings obtained from such testing on nonshielded, nonmetallic-sheathed cable is very dependent upon the environment because the environment determines the characteristics of the return circuit. Low resistance readings may be caused by contaminated or moist cable ends, high humidity, etc.
Failure to clean water based cable pulling lubricants from the cable test ends has caused erroneous rejection of good cable.
Refer to the figures below for suggested hookup. Stay clear of energized cable. Operators must know the equipment. Be sure shields are grounded! Remember that insulated conductors are capacitors. Cables Not Installed: Remove end seals. Position one cable end to its lowest possible elevation. At the cable end having the highest elevation apply two layers of half-lapped HV insulating tape to act as a sealing cushion. Connect the cable ends to a dry nitrogen or dry air supply using hoses, valves, fittings, and flow regulators as shown in Figure 8.
Attach a one-gallon plastic bag to the exhaust end of the cable. Secure the bag with tape or clamps. Make a small vent hole by clipping one bag corner. As shown, several cables may be connected to the gas supply. Dry nitrogen is available from welding gas suppliers. Apply 15 — 25 psi gauge. Maintain pressure for at least eight hours after all indications of moisture have stopped.
The sulfate is available from scientific laboratory supply houses. A hardware store humidity gauge may also be used. Installed Cables: The splices and terminations must be removed if they interfere with the flow of air or nitrogen. The cable can then be purged as described above. Attenuation is the parameter most frequently measured and includes the attenuation of the cable as well as that of attached connectors.
Handheld optical power meters and light sources normally LED types for multimode and laser types for single mode fibers are used to determine the total attenuation of the fiber and any splices or connectors. A light pulse is sent down the fiber and as it encounters a fault, connector, splice, etc. An OTDR is able to determine the distance to the reflection and the amount of signal loss at that point.
OTDRs work on a radar-like principle. Small optical microscopes are used to visually inspect the workmanship of installed fiber optic connectors. Low cost handheld LAN cable testers are available that are used to certify the electrical performance, e. This characterizes the installed system with regard to near-end crosstalk, attenuation and impedance. Time Domain Reflectometers TDRs are devices used to locate faults, determine length, and measure attenuation of the cable.
TDRs analyze the reflections and report the amount of impedance mismatch and the location of faults. The nominal impedance of the connector indicates its basic match to the nominal impedance of the cable. The VSWR indicates the quality of the match. It includes mating and overall dimensions, materials, performance, and testing procedures for each type of connector covered. In selecting a connector, users generally consider cable size, frequency range, and coupling method.
Cable Size determines the connector series as subminiature, miniature, medium, or large. Frequency Range determines the upper frequency limit of the application.
The connectors can be used at lower frequencies but are not recommended at higher frequencies where performance especially VSWR becomes degraded. This is due to the difference between bayonet and screw couplings.
If the highest frequency of the application is 2 GHz, either connector can be used. Coupling Method determines the procedure for joining two mating connectors. The three common types are bayonet, screw, and snap-on.
Often the coupling method is the main difference between two series of connectors. For example, the BNC connector uses bayonet coupling; the TNC connector is essentially the same, but with a threaded coupling. Figure 9.
The tight interface of the threads, especially when subjected to vibrations, allows the connector to maintain a low VSWR up to 11 GHz with flexible cable and up to 15 GHz with semirigid cable.
They were originally designed for high energy physics applications. They meet MIL-C requirements up to Their main application is in cost sensitive consumer applications. It is the standard coaxial connector for many coaxial cable based local area networks, including Ethernet and other IEEE networks using medium size coaxial cable. Most connectors are terminated to the cable by a single crimp on the attached ferrule.
They are designed to meet FCC Federal Communication Commission specifications and dimensions, including wire gauge and conductor insulation diameter. Some are designed for use with wires with solid conductors, others for stranded wire. The wiring configuration varies, depending on the wiring method selected for the system. With the locking tab down, the conductors are inserted into the rear of the plug in a specific pattern.
The pins of the plug are numbered 1 through 8 from left to right as shown in Figure 9. Inch mm O. Inch mm 1, 0. Note: Bolt illustrations not drawn to scale. There are a variety of types available. ST and SC connectors are the most common types.
The opto-electronic equipment used will have an optical interface of a specific connector type. Therefore, this type must be used at the equipment interface. It is suggested, though, to use ST or SC type connectors in all of the distribution cabinets and to use custom cable assembly jumpers from the cabinets to the opto-electronic equipment.
Step 2: Determine the mode type and fiber OD. Fibers are either multimode or single mode. Step 3: Determine the cable construction type. There are four basic construction types to choose from. They are jumper cordage, multifiber tight buffered building cable, multifiber-fanout breakout building cable, and outdoor loose buffer cable.
Simplex, zipcord, and dual subunit cordages can be connectorized with no additional apparatus. Round duplex requires a breakout kit if: a the cordage is being used to make an assembly, and b connectors other than duplex such as FDDI are to be used. As a result, a crimping procedure is not used during the installation of a connector.
The connector can be installed directly onto a tight buffered fiber. Thus, each subunit is effectively a simplex cable. A connector can be installed directly onto these subunits with no additional hardware required. Virtually all outdoor cables require a breakout kit in order to connectorize the fibers. Choose a connector which matches the breakout kit subunit type for a proper fit. The ST type connector is spring-loaded, which keeps the fibers and connector tips in physical contact PC inside the coupling sleeve.
These connectors, because they are PC type, have a key to lock the contacting position and prevent tip rotation, protecting the fibers from scratches and chips. The key also ensures performance repeatability from reconnection to reconnection. The bayonet latching offers easier connection and disconnection. There are several versions available. The variations are mainly the tip material. The glass insert protrudes slightly from the ceramic, so if the fiber end still needs more polishing even after the fiber end becomes level with the glass insert, the connector tip can be further polished, thus polishing both the fiber end and the glass insert simultaneously.
Stainless steel tips offer durability. The stainless steel ST type connector remains durable from reconnection to reconnection. Plastic tip connectors offer a low cost solution when loss is not critical. Be alert, though, that all plastics are NOT alike. Mating different plastics could lead to intermolecular migration, which means material from one tip will, over time, embed itself in the opposing tip and vice versa. This will cause an increase in attenuation. These attributes include a 2.
Because of its square design and latching, the SC subscriber connector can be arranged in very high density patching systems. Another feature and possibly the most important is the standard non-optical disconnect incorporated into the design. A pulling force applied on the cable will not separate the physically contacting tips within a coupler; a feature very attractive to securing a successful transmission of information. This allows the connector manufacturers flexibility to design their own style into a compliant connector.
The FDDI connector also has a keying system to prevent connections of incompatible network nodes. There are four receptable keys: A, B, M, and S. The A and B keys are used for dual attach network devices. The M and S keys are used off of the main ring for single attach network connections. Originally designed for the military, this connector is small in size and easy to work with.
Because it has been in existence for a long time, many manufacturers produce SMA connectors. Though there are a few variations in tip material, this connector is most often an epoxy oven or 24 hour cure type installation. Tip materials include stainless steel, nickel-plated brass, ceramic, plastic, and aluminum. In this country, the only application with maybe one or two exceptions is with the IBM , and token ring products. They are stainless steel tip and body and are virtually all multimode only.
The FC is a physical contacting connector within its coupler as well as being keyed to prevent tip rotation and subsequent damage. Most FC connectors have a ceramic tip and are an oven or 24 hour cure epoxy type installation system. These connectors are typically used for single mode applications but multimode connectors are available. Since the telephone industry was the first to use fiber optics, the telephone industry has been the primary user of the biconic connector.
It offers high performance though it is large in size and cumbersome to handle. A reel not matched to the weight of the cable wound on it may be damaged during shipment. All wire and cable has a minimum safe bending radius. If cable is subjected to bends sharper than the minimum radius, damage to the material is likely. The minimum drum hub diameters given in Section Single- and multiple-conductor nonmetallic-covered cable 1.
Nonshielded and wire shielded, including cable with concentric wires a. Over 2, Volts 1 Nonjacketed with concentric wires. Tape Shielded. Single- and multiple-conductor metallic-covered cable 1. Tubular metallic sheathed a. Aluminum 1 Outside diameter—1. Wire armored. Flat tape armored. Corrugated metallic sheath. Interlocked armor. Multiple single conductors cabled together without common covering, including self-supporting cables—the circumscribing overall diameter shall be multiplied by the factor given in item A or B and then by the reduction factor of 0.
Combinations—For combinations of the types described in items A, B and C, the highest factor for any component type shall be used. Single- and multiple-conductor cable in coilable nonmetallic duct Outside diameter of duct, inches—0.
Over 1. Fiber Optic Cables. In all other cases, the outside diameter is the diameter outside of all the material on the cable in the state in which it is to be wound upon the reel.
The multiplying factors given for item E refer to the outside diameter of the duct. Capacity Max Wt. Reel Code No. Cable Diam. Clearance 2. All capacity figures are based on minimum drum diameter of 16 times cable diameter.
All dimensions in inches, all weights in pounds. Capacity Max 10, Wt. Capacities for the W Reel are based on a mimimum clearance of 4.
B Arbor Hole In. D Drum Diameter In. T W Overall Width In. Reel Weight Lb. Reel Traverse In. Larger diameter cables or those requiring on-the-reel tests may necessitate a longer lead. Caution must also be used to prevent damage to the cable end as it is frequently utilized for hipot, continuity, or other tests.
Be sure all staples and nails that might damage the cable are removed. This will assure that the material on the reel will not unwind or slip during shipping and handling operations. The cable should be stapled or tied with rope to a staple in the upper portion of the inside of the flange as shown in the diagram below.
Figure Greater cable loading than this greatly increases the likelihood of forklift and other damage. Feeding Cable onto Reel Care must be used when feeding cable onto the take-up reel. A uniform tight pattern must be maintained all through the rewind operation until the end of the cable is secured to the flange.
Sealing of Cable Ends Both cable ends should be sealed against the entrance of moisture. Smaller diameter cables should be sealed with PVC tape such as 3M Scotch 33 or with end caps end caps preferred. At the start of each length, secure the conductors to the outside of the interlocked armor or outer covering over the interlocked armor with a light gauge 10 to 16 AWG lashing wire. As an added precaution, check the finish end of each cable after rewinding to insure that the cable and interlocked armor are still lined up with each other.
Do not store or ship reels on their side. Storage or shipment of the reel while lying on its side greatly increases the likelihood of tangling and damage to the cable.
Government Specifications Military Specifications TITLE Chapter Electric cables. Government Specifications Superintendant of Documents U. Height above bottom, distance from specimen surface. Not applicable in the UL version. This dimension is mm in the UL version. Two each on two different sizes of specimens. Not yet specified. A 25 ft long Steiner Tunnel is used for the test, with intake and exhaust ducts and a means of regulating flow velocity of air through the tunnel.
Windows at 1 ft intervals allow for flame spread measurements, and an optical device in the exhaust of the chamber measures smoke density. The cable samples are mounted in a cable tray in one layer in the tunnel and the tunnel is sealed. Two circular burners are mounted vertically at the intake end of the tunnel just in front of the cable tray. Flame spread and smoke density are monitored throughout the test.
A cable is listed for plenum use if flame spread is less than 5 ft from the end of the ignition flame, and optical density is less than 0. This test simulates a fire in a nonflame stopped riser within a high-rise building. The chamber for the test is a 3 story block construction design. The burner is mounted on the edge of the riser hole on the floor of the second level. A mixture of air and propane is burned for thirty minutes and then shut off, extinguishing the burner flame.
A cable may be listed as riser cable if the flame does not propagate up to the floor of the third level. A steel ladder type tray 12 in. The center 6 in. A 6 to 1 mixture of air to propane is burned using a 10 in. The burner is placed horizontally 3 in. The flame is applied for twenty minutes and then removed.
A cable passes the vertical tray test if it does not propagate flame to the top of the tray 6 ft. For this reason each phase conductor of such a handbbook has additional insulation. Larger sizes are more easily handled by applying a pulling grip over the cable or cables provided the pull is not too severe.
Typically, these external signals emanate from universal motors with brushes, fluorescent lights, personal computers, printers or other devices including copy machines, etc. Type 9 Thermocouple Cable: The ratio of the current flow to the potential difference causing the flow. Remember to use the radius of the surface over which the cable is bent, not the outside flange diameter of the pulley. The Code includes references to a stringent series of tests developed for flame testing of wires and cables.
A typical volt control cable is shown below: It is the standard coaxial connector for many coaxial cable based local area networks, including Ethernet and other IEEE networks using medium size coaxial cable. For information on the various types and their applications, see Chapter 5 on Armor. Interlocked Armor Cables When pulling interlocked armor cable it is necessary to grip both the armor and the conductors. TPE has good chemical resistance to all substances except hydrocarbons. A multiple conductor insulated cable with sector conductors has a smaller diameter than the corresponding cable with round conductors.
All capacity figures are based on minimum drum diameter of 16 times cable inforamtion. Write a customer review.
CPE can be conveniently colored over a wide range and will maintain color upon aging. Temperature limit of the thermocouple depends on the thermocouple wire: Satisfactory performance at even higher temperatures is possible if the exposures are brief or intermittent.
0コメント