How To Repair Fiber Optic Cable

101 Guidelines for Cobweb Optic Cable Installation

Oct 08, 2010

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Never directly pull on the cobweb itself. Fiber optic cables accept Kevlar aramid yarn or a fiberglass rod as their strength member. You lot should pull on the fiber cable strength members only!
Never exceed the maximum pulling load rating. On long runs, use proper lubricants and make certain they are compatible with the cable jacket. On really long runs, pull from the middle out to both ends. If possible, use an automated puller with tension control or at least a breakaway pulling center. Know and observe the maximum recommended load rating of the cable.
Never exceed the cable bend radius. Fiber is stronger than steel when you lot pull information technology directly, but it breaks easily when bent besides tightly. These volition impairment the fibers, perchance immediately, maybe non for a few years, but you will damage them and the cable must be removed and thrown away!
Always coil the cable off the spool instead of spinning it off the spool cease. This will put a twist in the cable for every plough on the spool! Never twist the fiber cable. Putting a twist in the cable tin stress the fibers too.
Make sure your fiber cablevision is long plenty for the run. Fiber splicing make things complicated and expensive. And it needs special protection. Attempt to go far in ane pull.
Indoor cables tin can be installed directly, but you might consider putting them inside innerduct. Innerduct provides a expert manner to identify fiber optic cable and protect it from harm, generally a result of someone cutting it past mistake! Y'all can get the innerduct with pulling tape already installed.
Plan the Installation. Create a detailed, written plan of installation. Yous can eliminate 95% of the problems installers tin encounter by simply creating this plan. The programme should include equipment and supplies, fiber cable specification, location of equipment, testing requirements, data forms for testing, personnel experience level and assignment, installation methods, identification of potential trouble areas, safety problems, etc.
Pull, do not push cables. Pushing can outcome in violation of the bend radius.
Monitor the supply reel. Monitoring the supply reel during installation is necessary to prevent violation of minimum bend radius.
Communicate forth the path of installation. When installing long runs, communicate and monitor along the path of the installation. Fiber cables can and exercise bound from unmonitored pulleys. The minimum crew should take one person monitoring the pulling equipment, ane monitoring the supply reel, and one analogous all involved in the installation.
Use proper tools and techniques. A vehicle for pulling the cablevision is not a proper tool, unless a breakaway swivel is also used. Proper techniques depend on the cable pattern and the location of the installation. For example, proper technique is pulling a cable into a conduit. Proper technique is placing or laying a cable in a cable tray or raceway.
Use cobweb optic cablevision lubricant. Lubricate the cablevision when installing in conduits. Lubrication reduces the pulling load and the chance of breakage. The lubricant has to be compatible with the cablevision jacket cloth.
Train installation personnel. Properly train and instruct the people who will practise the installation. Proper preparation reduces expense through reduction of breakage and excess attenuation.
Use the figure 8 technique. Divide long pulls into several shorter pulls, using the figure 8 technique for storing cablevision at the intermediate locations. The cablevision is placed on the ground in a effigy 8 pattern. This pattern is large, at least x-20 anxiety from top to bottom of the blueprint. When all the cable is placed in this pattern, the pattern is lifted and flipped over, so that the loose end is on peak. This loose end is pulling into the next section of conduit or duct. This technique prevents twisting in the cable.
Comply with vertical rise limits. Know and find the maximum vertical rise distance limit. Exceeding this limit tin can upshot in fiber breakage, excess attenuation, and, in loose tube cables, fibers sliding from cables. Cables in vertical installations that are longer than the vertical ascension limit must be tied off at distances less than this limit. Loose tube cables must be looped.
Allow for thermal expansion and contraction. In outdoor installations, a common do of ii.five foot sag for 150 foot span is good for thermal expansion and wrinkle. Failure to permit for thermal expansion tin can result in increased attenuation and breakage of fibers.
For tough installations, apply loose buffer tube fiber cables. Loose tube cables can be more forgiving of abuse than tight buffer cables. The reason is that the excess length of fiber in the buffer tube and the ability of fiber to motion from low stress region to higher stress region.
Observe the temperature operating range. Install a cable in locations in which the temperature range imposed is within the temperature operating range. Violation of the temperature operating range can result in excessively loftier attenuation.
Cap or seal water blocked cables. Cap off or seal the ends of cables with water blocking gel or grease. These materials tin flow out of the cable, causing maintenance problems in cablevision end boxes.
Protect fibers and buffer tubes. Confine fibers and buffer tubes in protective structures, such as splice trays and cable cease boxes. Fibers and buffer tubes do not take sufficient forcefulness to resist breakage due to normal handling of copper cables.
Loop vertically installed loose tube cables. Install vertical, unfilled, loose tube cables with loops to prevent the cobweb from slipping to the bottom of a vertical run. If this happens, attenuation tin increase and fibers eventually break.
Cheque continuity and attenuation. Bank check the continuity and attenuation of the cable before each operation. These checks should exist performed as-received/before installation, after installation, after splicing, and afterward connector installation.
Marker cable as "Fiber Optic Cable". Marker cable as "cobweb optic cable" in all locations in which information technology tin can be easily reached. Such marking will warning electricians to the nature of the cable.
Make Equally-Built Information logs. Make as-built information logs on all cables. Keep these data available to those who will perform maintenance and troubleshooting. These information logs should include both insertion loss measurement and OTDR measurements.
Safety precaution – no food, drink or smoke. Do non eat, drink, or smoke in any expanse in which bare glass cobweb is created. Bare drinking glass fibers can crusade splinters which are very difficult to find and remove.
Safety precaution – do not look into fiber without checking status. Never look into a fiber, cable, or connector unless you lot know for sure that there is no laser light in the fiber. For extensive work with cobweb eyes, rubber glasses with IR filter is recommended.
Go out service loops. Leave cablevision and fiber service loops everywhere. Yous will regret non doing and then. Service loops allow you lot to pull excess cable or fiber into a location where you accept experienced a problem. It is much cheaper to pull in a service loop than to replace an entire run of fiber cable.
Segregate or isolate the work area. Rope off or otherwise isolate the area of cable installation to prevent access to unauthorized or untrained personnel. This will avoid condom problems such as cobweb splinters and unintentional abuse.
For direct burying installations, the cablevision should lie flat in a trench, complimentary of any large stones or boulders that may deform the cable.
Do not let vehicles to drive over a cable.
Ensure that the proper cable length has been installed before cut off excess cablevision.
Avoid placing cablevision reels on their sides or subjecting them to shock from dropping.
Fiber optic cables should exist placed in their ain dedicated ducts or trays. Practice non mix copper cable and fiber cablevision in the aforementioned ducts or trays.
Afterward the fiber optic cable is installed into a duct or innerduct, end plugs should be installed to provide an effective water seal. The ducts and innerducts should be kept free of debris and maintained watertight at all times.
Ducts and innerducts should be sized to meet nowadays and future cable installation requirements. A maximum 40% fill up ratio is a good rule of thumb to follow for duct size.
The fiber pulling rope or record should be sequentially marked (foot or meter) for like shooting fish in a barrel identification of distance.
The pulling tape should have a rating for greater than maximum anticipated pulling tension.
Before the first of whatever cable pull, all ducts and cable vaults should be carefully inspected for damage or deterioration, and to accost any safety concerns.
The electric spark generated by a fusion splicer can cause an explosion when flammable gases are present. Fusion splices should therefore not exist used in vaults.
To minimize cable tensions, reel vault locations should be prepare near the sharpest curve locations. Pulling and reel locations should also be set at corner vaults where possible.
Place lightwave equipment that will be used and ensure that the equipment will function properly with the fiber cable being installed.
When an outdoor rated fiber cable enters a building, it should be spliced to an indoor-type fiber cable within 50 feet from the cable entrance to meet NEC code.
All vertical cable must be secured at the tiptop of the run. A divide mesh grip is recommended to secure the cable.
The vertical attachment point should exist carefully chosen to comply with the cable's minimum bend radius while holding the cablevision securely.
If hereafter cable pulls in the same duct or conduit are a possibility, the apply of innerduct to sectionalize the available duct infinite is recommended. Without this partition, additional cable pulls can entangle an operating cable and could cause an break in service.
A pocket-size amount of slack cable (twenty-30 feet) can be useful in the event that cable repair or relocation is needed.
Cables should be tested later on shipping. Damage to cabling can occur during shipping or installation. Failing to test cobweb cabling after information technology is delivered is a common mistake made by installers.
If insertion loss suddenly increases with an adapter or connector, the crusade may be dirt. Y'all should always make clean the connector and adapter before plugging them in.
Properly attach the pulling eye and swivel to the cable. Ensure that the pulling eye and swivel assembly take no abrupt edges and can hands fit through all conduits, pull boxes, and cable trays.
When pulling the fiber out of a department, coil the cable on the floor in a figure 8 blueprint to avoid twisting. Continue the cable pull until all the cable has been pulled through.
Identify the exact fiber optic cable route and ensure that it meets all installation specifications. Obtain all required fiber cable installation authorizations and permits along the route.
Tape all required fiber optic facility details, including proper route drawings, fiber assignments, loss readings, OTDR traces, etc.
Gear up emergency repair plans.
Only remove connector and adapter duct caps prior to making the connection. Practise non let the connector tough whatever surface once the duct cap has been removed.
When making a connexion, the connector should adhere to the adapter smoothly. Practice not rotate the connector when making the connection.
For screw-in connectors such every bit FC connector, tighten them only "finger tight". Never force a connector onto an adapter.
A cobweb optic cable should be tested three carve up times during an installation: on the reel, the splicing test, and the terminal acceptance test.
Extreme caution should be observed when performing an aerial installation. The proper personnel should be contacted and so that they are on the site when work is performed nearly high-voltage lines.
Cables that are installed in the vicinity of high-voltage ability lines should be grounded, including all-dielectric cables.
Maintain proper clearance between the cobweb optic cable and power cable at all times. Always make allowances for power cable sag due to atmospheric condition and current conditions. Cablevision sag increases in warm weather or when power cable is passing heavy current.
When a steel messenger wire is used for aerial installation, avoid zigzagging the messenger wire from one pole side to the other. Instead, brand sure it is kept on one side as much every bit possible.
Follow Edifice Codes: Always obey all local, and national, fire and edifice codes. Exist sure to "firestop" all cables that penetrate a firewall. Use plenum rated cablevision where it is mandated, etc., etc.
Exercise make every endeavor to pull cables from a conduit in as straight an angle every bit possible. Pulling on an angle can cause damage to the cablevision.
Use a generous amount of cable pulling lubricant on the entire run, especially on the leader (pulling center & mesh). The person may stop the cable pull from time to time to prepare and apply more lubricant. Utilize only lubricant that is expressly designed for cable pulling. When working in freezing temperatures, use a lubricant that is designed non to freeze.
Information technology is of import to use a rope size that give minimal stretching during the pull. Stretching of the rope is undesirable for several reasons including that it makes for a very unstable pull, and takes away control from those doing the pulling.
Apply farthermost caution when removing the pull eye. Do not use a bract to slit the mesh. Instead, utilize a pair of electricians scissors or diagonal cutters. Work your way from the back of the cable toward the pull eye, while lifting the mesh upward, away from the cable.
It is extremely of import to take an authentic measurement when planning an gild for a custom pre-terminated cobweb optic cable assembly. These custom assemblies cannot exist returned unless out of box defective.
Optional pulling eyes are highly recommended. The pulling eye (and associated cable netting) will protect the pre-terminated ends during the pull.
Underground conduits, if newly installed, should exist a minimum size of between i.5″ to ii″. If the run is long, or if y'all conceptualize the possibility of boosted future pulls; And then you may want to install a conduit of up to 4″ (or greater).
Try to design the conduit run with a few bends as possible. If in that location are likewise many bends in the run and then you may consider installing junction boxes in lieu of bends.
Cable may exist placed in a Figure 8 pattern if information technology needs to be removed from the reel. This blueprint minimizes the aggregating of cable twist. Care should be taken to prevent cable damage while the cable is in this configuration.
The cable should non be installed in environments exceeding its specified maximum and minimum installation temperature. For loose tube and ribbon cablevision this is typically specified for an installation temperature of -30C to +75C.
Riser cables are generally required for vertical applications and plenum cables are required where there is a positive air pressure infinite.
The cable weight in an unsupported vertical ascent shall be less than the specified long term operating load. Your manufacturer'south specification canvas should be consulted for specifics. Intermediate cablevision attachment points however are recommended for optimum performance.
Bonding and Grounding: Follow your company and local/national bonding and ground procedures when using fiber cable with metal components.
When pulling the cablevision off the reel onto messenger mounted cable blocks, special intendance should be given to size and location of the 1st and concluding pulley. The reel should be placed every bit far equally practical from the 1st pulley to minimize the angle of the 1st curve. A cablevision shoot/pulley larger than the specified bend radius is recommended to minimize the cable bend at the showtime and last pulley locations or at any location with a change in direction.
On runs from 40m to 100m, use proper lubricants and brand sure they are compatible with the cable jacket.
On runs over 100m, use proper lubricants and pull from the middle out to both ends.
If possible, utilize an automated puller with tension control or at least a breakaway-pulling eye.
Avoid placing cobweb optic cables in raceways and conduits with copper cables to avoid excessive loading or twisting.
Attach cables with plastic clamps having large surface areas. Avert pinching or squeezing cable. Cablevision clamps should be installed manually with gentle pressure.
Apply a moisture wipe to loosen particles on the terminate of the cablevision connector using a circular or direct wiping motion while using care to avoid wiping over expanse of pad that has already been used. Do not employ a back and forth scrubbing action.
Cleaning fiber optic transceivers. Choose an optical grade lint free swab that fits easily into the transceiver barrel. The swab should be gently placed into the barrel of the connector and rotate no more than than 1 plough. DO NOT rotate back-and-forth or round-and-round because this could grind debris into the transceiver. The swabs should only be used In one case.
Cable Bravado or Jetting in Duct Applications. A crash examination should be performed to decide the maximum push force. Excessive pushing will crusade the cable to cork spiral in the duct or fold over which volition damage the fiber.
Cable blowing. Consider the route to decide the maximum blowing distance. Follow the bravado equipment suppliers bravado distance recommendations; 3000 to 6000 feet is a typical bravado length. A set up with multiple blowing machines may be required.
Cable blowing. Maintain proper air flow to "blow" the cablevision verses "pushing" the cable. Use an air compressor with a minimum of 375 cfm. The minimum air pressure in the duct should be 100 psi with 125 psi recommended.
Cable blowing air cooler. Air compressor cooler should be used every bit recommended by the blower equipment manufacturer. Typically this is when the ambient air temperature exceeds 80˚F.
Cablevision blowing. Employ merely cable/duct lubricants recommended by its bravado equipment manufacturer for optical fiber cablevision.
Do non shop cable inside the closure or pedestal unless there is enough room to accommodate the minimum specified cable curve radius.
Grounding: Cable with metallic components shall follow the bonding and grounding requirements of the customer and local or national codes.
Midspan admission of fibers in buffer tubes: To minimize fiber damage, employ a Midspan Access Tool to open the buffer tube such as a Corning Frequently-000. Care should be taken to use the right insert size.
Conduit Installations General Information: Try to design the conduit run with a few bends equally possible. If there are too many bends in the run so you may consider installing junction boxes in lieu of bends.
Utilise plastic bushings on conduit ends to avoid damage to the cable during the pull.
For cables using aramid yarn lonely every bit the strength member, the jacket can be removed to expose the yarn. The yarn should be tied in a knot with the pull rope, so that the jacket volition not be inadvertently used for forcefulness. Optionally, the jacket can be tied into a tight knot before pulling. After pulling, the knot should be cut off.
For cables using aramid yarn and an fiberglass central member, a pulling grip should be used. The force member should be attached independently. This tin can be accomplished by weaving the strength member into the fingers of the grip, and then taping it together. All strength members should exist gripped equally to ensure proper distribution of tension.
Buried cable installations. Identify cablevision locations with surface markers. Conceptualize obstructions.
Test jumpers must be of the aforementioned fiber cadre size, operation and connector blazon every bit the cable system (e.yard. fifty/125 μm FX2000 jumpers for a fifty/125 μm FX2000 optical fiber system) and shall be one to five meters long.
Number of xc degree turns. The number of ninety degree turns on a pull shall not exceed 6 for aerial cables and four for cloak-and-dagger cable-in-conduit.
Pulling surreptitious fiber optic cablevision. Special fiber optic blocks should exist used on all turns or angles.
And always utilize a swivel pulling eye because pulling tension will cause twisting forces on the cable.
If cables are nowadays in ducts through which the fiber cable is to be pulled, the existing cable types should be identified and the owner of the cable called to inform him of the activity, and to place whatever safety concerns.