Installation of a high-density optical cross. Description of installation of fiber optic couplings and optical cross connects Optical cross connect how to install
Fibers are charged into the splicing machine
Hello, Habr readers! Everyone has heard about optical fibers and cables. There is no need to tell where and what optics are used for. Many of you come across it at work, some develop backbone networks, some work with optical multiplexers. However, I have not come across a story about optical cables, couplings, cross-connects, or the technology itself for splicing optical fibers and cables. I am an optical fiber solder, and in this (my first) post I would like to tell and show you how all this happens, and in my story I will also often be distracted by other related things. I will rely mainly on my own experience, so I fully admit that someone will say “this is not entirely correct”, “this is non-canonical”.
There was a lot of material, so it became necessary to break the topic into parts.
In this first part you will read about the design and cutting of cables, about optical instruments, and about preparing fibers for welding. In other parts, if the topic turns out to be interesting to you, I will talk about the methods and show on video the process of splicing the optical fibers themselves, about the basics and some nuances of measurements in optics, touch on the topic of welding machines and reflectometers and other measuring instruments, and show the work stations of the solder ( roofs, basements, attics, hatches and other fields with offices), I’ll tell you a little about cable fastening, about wiring diagrams, about placing equipment in telecommunication racks and boxes. This will certainly be useful to those who are planning to become a solder. I flavored all this with a large number of pictures (I apologize in advance for the paint quality) and photographs.
Be careful, there are a lot of pictures and text.
Introduction
First, a few words about me and my work.I work as an optical solder. He started as a telephone operator and installer, then worked in an emergency crew servicing trunk optics. Now I work in an organization that takes out general contracts for the construction of facilities and communication lines from various companies. A typical construction project is a cable line connecting several GSM base station containers. Or, for example, several FTTB rings. Or something smaller - for example, laying a cable between two server rooms on different floors of a building and welding cross-connects at the ends of the cable.
If the tender is won, suitable subcontractors are sought to carry out the work (design, survey and construction). In some regions these are our subsidiaries, in some we have our own equipment and resources, in some we hire independent companies. Our shoulders mainly fall on control, elimination of jambs of subcontractors and various force majeure, all kinds of coordination with land owners and administrations, sometimes drawing up as-built documentation for the constructed facility (documentation - mainly RD 45.156-2000, here is a list, plus more is added section with different licenses) and so on. Often work with optics is needed: welding or welding somewhere an optical coupling or cross-connect, eliminating the consequences of a support knocked down by a street racer or a tree falling on a cable, conducting an input inspection of the cable drum, taking reflectograms of the area, etc. These are the tasks I perform. Well, and along the way, when there are no optics tasks, there are other tasks: from loading and installation through courier and delivery to copying and paper work. :)
Optical cable, its types and internals
So what is an optical cable? Cables are different.
The design ranges from the simplest (a shell, underneath there are plastic tubes-modules containing the fibers themselves) to the super-sophisticated (many layers, two-level armor - for example, in underwater transoceanic cables).
According to the place of use - for external and internal installation (the latter are rare and usually in high-class data centers, where everything must be perfectly correct and beautiful). According to the installation conditions - for suspension (with Kevlar or cable), for soil (with armor made of iron wires), for installation in cable ducts (with corrugated metal armor), underwater (complex, ultra-protective multi-layer structure), for suspension on power line supports (in addition to transmitting information, they play the role of a lightning protection cable). In my practice, the most common cables used are for hanging on poles (with Kevlar) and for laying in the ground (with armor). Less often you come across them with a cable and with corrugated armor. You also often find a cable that is essentially a thin paired optical patch cord (yellow jacket for a single mode and orange for a multimode, a bit of Kevlar and one fiber; two jackets are paired). Other optical cables (without protection, underwater, for installation indoors) are exotic. Almost all the cables I work with are designed like the picture below.
1 - central power element(in other words, a rod made of fiberglass, although there may also be a cable in a polyethylene sheath). Serves to center tube modules and impart rigidity to the entire cable. The cable is also often secured to it in a coupling/cross-connection, clamped under a screw. When the cable is strongly bent, it has the sneaky property of breaking, breaking the modules with some of the fibers along the way. More advanced cable designs contain this rod, covered in a polyethylene sheath: then it is more difficult to break and will cause less damage to the cable if broken. The rod can be the same as in the picture, and very thin. The tip of such a rod is an excellent abrasive tool for fine work: for example, cleaning relay contacts or an area of a copper part for soldering. If you burn it a couple of centimeters, you get a nice soft brush. :)
2 -
themselves optical fibers(in the picture - in varnish insulation). Those very thin fibers-light guides, for the sake of which everything is started. The article will only talk about glass fibers, although plastic fibers also exist somewhere in nature, but they are very exotic, cannot be welded with devices for welding optics (mechanical connection only) and are suitable only at very short distances and I personally have not encountered them . Optical fibers come in single-mode and multi-mode, I have only encountered single-mode, since multi-mode is a less common technology, can only be used over short distances and in many cases can be perfectly replaced by single-mode. The fiber consists of a glass “shell” made of glass with certain impurities (I won’t dwell on chemistry and crystallography, since I don’t know the topic). Without varnish, the fiber has a thickness of 125 microns (slightly thicker than a hair), and in the center of it there is a core with a diameter of 9 microns made of ultra-pure glass with a different composition and with a refractive index slightly different from the shell. It is in the core that radiation propagates (due to the effect of total reflection at the core-cladding boundary). Finally, on top of the 125-micrometer cylinder of the “shell” is covered with another shell - made of a special varnish (transparent or colored - for color coding fibers), which EMNIP is also two-layer. It protects the fiber from moderate damage (without varnish, although the fiber bends, it is bad and easy to break; the fiber will simply crumble if a cell phone is accidentally placed on it; but with varnish, you can safely wrap it around a pencil and pull it quite hard - it will withstand). It happens that a cable span sags on just the fibers: all the sheaths, Kevlar, are torn (burned, cut), the central rod bursts, and some 16 or 32 125-micrometer glass fibers can support the weight of the cable span and wind loads for weeks! However, even in varnish, fibers can be easily damaged, so the most important thing in the work of a solder is meticulousness and accuracy. One awkward move can ruin the results of a whole day of work or, if you’re really unlucky and there’s no reservation, you can drop it for a long time trunk connection(if, while delving into the “combat” main coupling, you break the fiber with DWDM under the spine at the cable exit).
There are many types of fibers: regular (SMF or simply SM), dispersion-shifted (DSF or simply DS), non-zero dispersion-shifted (NZDSF, NZDS or NZ). It is impossible to distinguish them externally; the difference lies in the chemical/crystalline composition and, possibly, in the geometry of the central core and in the smoothness of the boundary between it and the shell (unfortunately, I have not fully clarified this issue for myself). Dispersion in optical fibers is a harsh and difficult thing to understand, worthy of a separate article, so I’ll explain it more simply - dispersion-shifted fibers can transmit a signal further without distortion than simple ones. In practice, solders know two types: simple and “with offset”. In a cable, the first module is often allocated for “offset”, and the rest - for simple fibers. It is possible, but not advisable, to join a “displacement” and a simple fiber; this causes an interesting effect, which I will talk about in another part, about measurements.
3 - plastic tube modules, in which fibers float in a hydrophobe.
Cable stripped into modules
They easily break (or rather, suddenly bend) when bent, like telescopic antennas on household receivers, breaking the fibers inside them. Sometimes there is only one module (in the form of a thick tube), and it contains a bundle of fibers, but in this case too many are needed different colors for marking fibers, therefore several modules are usually made, each of which has from 4 to 12 fibers. There is no single standard for colors and the number of modules/fibers; each manufacturer does it their own way, displaying everything in the cable passport. The passport is attached to the cable drum and is usually stapled to the wood directly inside the drum.
Cable passport
Typical cable passport. Sorry for the quality.
However, there is hope that, say, the DPS cable from the manufacturers Transvok and Beltelekabel will still be the same in configuration. But you still need to look at the datasheet for the cable, which always shows detailed colors and what type of fibers are in which modules. The minimum capacity of an “adult” cable that I have seen is 8 fibers, the maximum is 96. Usually 32, 48, 64. It happens that out of the entire cable 1 or 2 modules are occupied, then instead of the remaining modules, black dummy plugs are inserted (to ensure the overall parameters cables have not changed).
4 - film, braiding the modules. It plays a secondary role - damping, reducing friction inside the cable, additional protection from moisture, holding the hydrophobe in the space between the modules and, possibly, something else. It is often additionally tied with threads crosswise and moistened on both sides with a hydrophobic gel.
5 - thin inner shell made of polyethylene. Additional protection from moisture, protective layer between Kevlar/armor and modules. May be missing.
6 - Kevlar threads or armor. In the picture, the armor is made of rectangular rods, but much more often it is made of round wires (in imported cables, the wires are steely and difficult to cut even with cable cutters; in domestic ones, they are usually made of nail iron). The armor can also be in the form of fiberglass rods, the same as the central element, but in practice I have not encountered this. Kevlar is needed so that the cable can withstand high tensile strength without being heavy. It is also often used instead of a cable where there should be no metal in the cable to avoid interference (for example, if the cable hangs along the railway, where there is a contact wire with 27.5 kV nearby). Typical values of permissible tensile force for a cable with Kevlar are 6...9 kilonewtons, this allows it to withstand a long span under wind load. When cutting, Kevlar is terribly dull cutting tool. :) Therefore, it is better to cut it either with special scissors with ceramic blades, or bite it off with cable cutters, which is what I do.
As for the armor, it is designed to protect an underground cable lying directly in the ground, without protection in the form of a plastic pipe, cable duct, etc. However, the armor can only protect against a shovel; an excavator will still tear any cables in flight. Therefore, the underground cable is laid in the ground at a depth of 1 m 20 cm, and above it at a depth of 60 cm a yellow or orange warning tape with the print “Caution” is placed. Don't dig! Below is the cable,” and also bollards, warning signs and notices are placed along the route. But they still dig and tear.
7 - external thick polyethylene sheath. She is the first to bear all the burdens during cable installation and operation. Polyethylene is soft, so it is easy to cut it if the cable is not carefully tightened. It happens that when laying an underground cable, the contractor will tear this sheath several meters down to the armor and not notice that moisture gets into the cable in the ground despite the hydrophobe, and then upon delivery, when testing the outer sheath with a megohmmeter, the megohmmeter shows low resistance (high leakage current) . 
If a hanging cable touches concrete pillar or wood, polyethylene can also quickly be worn down to the fibers.
Between the outer shell and the armor there may be polyethylene film and some hydrophobic gel.
In Russia, unfortunately, optical fibers are no longer produced (here, alas, a joke about polymers would be appropriate). There is a Russian laboratory that produces experimental fibers for special purposes, as suggested by esvaf.
They are bought from companies such as Corning, OFS, Sumitomo, Fujikura, etc. But cables are made in Russia and Belarus! Moreover, in my practice, 95% of the cables I worked with are cables from Russia or Belarus. In this case, imported fiber is installed in the cable. Offhand, from my experience, I recall such cable manufacturing companies as Beltelekabel, MosCable Fujikura (MKF), Eurocable, Transvok, Integra-cable, OFS Svyazstroy-1, Saransk-cable, Incab. There are others too. Of the imported cables, only Siemens remains in my memory. Subjectively, all cables are similar in design and materials and do not differ much in quality.
Here, in fact, I talked about the design of optical cables. Go ahead.
Cable cutting: necessary tools and techniques
Cable cutting, like welding, requires a number of specific tools. A typical set of an assembler-soldier is a suitcase with tools “NIM-25”, it contains all the necessary strippers, cable cutters, screwdrivers, side cutters, pliers, a breadboard knife and other tools, as well as a pump or bottle for alcohol, a supply of hydrophobic solvent “D- Gel", non-woven lint-free wipes, electrical tape, self-adhesive number markers for cables and modules and other consumables.
After completion consumables(ties, worm clamps, etc.) and some auxiliary tools it is quite sufficient for working with optics. There are also other sets, richer and poorer in configuration (“NIM-E” and “NIM-K”). The weak point of most kits is the poor quality of the “aluminum type” case, which only looks nice, but in fact consists of thin fiberboard covered with textured/corrugated foil, and aluminum thin corners with rivets. It does not withstand long-term use in field and urban conditions, and has to be repaired and strengthened. In my case, the case lasted 3 years and, being all tattered, held together with corners and bolts, with a “collective farm” organizer instead of the original one, it was replaced with a regular one plastic box for tools. Some tools and materials from the standard set may be of poor quality. I personally didn’t need some tools. Some have already been replaced within 3 years of operation. As the “branded” consumables are used up, some are replaced with “improvised” ones without compromising the quality of work. Thus, factory-made non-woven lint-free wipes for wiping fibers are easily replaced toilet paper"Zeva plus" type. :) The main thing is that it is unflavored. Instead of expensive (about 800 rubles per liter) D-Gel, if you work outdoors, you can use AI-92 gasoline.
When cutting cables, it is important to maintain the lengths of the cable elements in accordance with the requirements of the instructions for the coupling: for example, in one case it may be necessary to leave a long power element to secure it in the coupling/cross-connect, in another case it is not required; in one case, a pigtail is braided from Kevlar cable and clamped under a screw, in another case, the Kevlar is cut off. It all depends on the specific coupling and the specific cable.
Let's look at the cutting of the most typical cable:
A) Before cutting a cable that has been in damp for a long time or without a waterproofed end, you should cut off about a meter of cable with a hacksaw (if reserve allows), since prolonged exposure to moisture negatively affects the optical fiber (it may become cloudy) and other elements of the cable. Kevlar threads in a cable are an excellent capillary that can “pump” water tens of meters into itself, which is fraught with consequences if, for example, high-voltage wires run parallel to the cable: currents can begin to flow through wet Kevlar, the water evaporates, crushes from the inside the outer shell, the cable comes with bubbles and new moisture gets in through the bubbles from the rain.
B) If the cable design has a separate cable for suspension (when the cable is in cross section has the shape of a number “8”, where there is a cable at the bottom, a cable at the top) it is bitten out with cable cutters and cut off with a knife. When cutting the cable, it is important not to damage the cable.
B) To remove the outer sheath of the cable, use a suitable stripper knife. NIM-25 is usually equipped with a “Kabifix” knife as in the photo below, but you can also use a knife-stripper for electrical cables, which has a long handle. 
This stripper knife has a blade that rotates in all directions, which can be adjusted in length according to the thickness of the outer sheath of the cable, and a clamping element for holding it on the cable. Important: if you have to cut cables different brands, then before cutting a new cable you need to try the knife on the tip and, if it has cut too deeply and damaged the modules, the blade needs to be tightened shorter. It can’t be worse when the coupling has already been welded, and suddenly, when laying the fibers, one fiber suddenly “jumps out” of the cable, because during cutting, the knife caught the module and broke this fiber: all the work is in vain.
Using a stripper knife to remove the outer sheath of the cable, a circular cut is made on the cable, and then from it two parallel cuts are made from opposite sides of the cable towards the end of the cable so that the outer sheath breaks into two halves. 
It is important to set the length of the blade of the stripper knife correctly, since if the blade is too short, the outer shell will not easily separate into two halves and it will take a long time to tear it off with pliers, and if the blade is long, you can damage the modules deep in the cable or dull the rotating blade on the armor.
D) If the cable is self-supporting with Kevlar, then the Kevlar is cut with cable cutters or scissors with special ceramic blades. 
Wire Bites
Kevlar should not be cut with a knife or simple scissors without ceramic linings on the blades, as Kevlar quickly dulls the metal cutting tool. Depending on the design of the coupling, it may be necessary to leave a certain length of Kevlar for fixation; this will be stated in the coupling installation instructions.
If the cable is intended for laying in a telephone sewer and the armor contains only metal corrugation (so that rats do not gnaw through), it can be cut longitudinally with a special tool (reinforced plow knife). Or, carefully make a circular mark on the corrugation with a small pipe cutter or even an ordinary knife and, shaking , to achieve an increase in metal fatigue at the risk point and the appearance of a crack, after which you can remove part of the corrugation, bite the modules and pull off the corrugation. This cutting must be carried out especially carefully, since it is easy to damage the modules and fibers: the corrugation is not very strong, it can wrinkle in the place where it is picked with tools, and when pulled from the fibers, sharp edges at the break point can pierce the modules and damage the fibers. A cable with corrugation is not the most convenient for cutting.
If the cable is armored with round wires, they should be cut off with cable cutters in small batches, 2-4 wires each. With side cutters it takes longer and is harder, especially if the wire is steel. Some couplings require a certain length of armor for fixation, and armor (including corrugated armor) often needs to be grounded.
E) For the inner, thinner sheath found in some cables (for example, self-supporting ones with Kevlar), you should use a separate, pre-set stripper knife (can be the same as for removing the outer sheath of the cable) so as not to interfere with the knife length settings every time when cutting the cable. In this case, it is especially important to correctly set the length of the blade in the stripper knife; it will be shorter than in a stripper for removing the outer sheath of the cable, since the inner sheath is much thinner, and immediately below it are modules with fibers. With a certain skill, you can use a regular breadboard knife to remove the inner shell, making a longitudinal cut with it, but there is a significant risk of damaging the modules. You can also use a clothespin stripper to cut coax.
E) Threads, plastic film and other auxiliary elements are removed from the modules using napkins and D-Gel/gasoline. The threads can be twisted one at a time, or can be torn off with a special sharp “plow” hook (may be included in the design of some stripper knives for removing the sheath). To remove the hydrophobe, use D-Gel solvent (colorless oily liquid, has an orange smell, toxic) or gasoline. However, be careful with gasoline: office employees who have gasoline pouring next to them will not be happy about the aroma. Yes, and it's a fire hazard.
You should work in disposable gloves (surgical, polyethylene or construction), since hydrophobe is a very unpleasant muck (the most unpleasant thing in the work of a solder!), it is difficult to wash, after using gasoline or hydrophobe, your hands remain greasy for some time, and after cutting the cable you have to weld the fibers, requiring clean hands and workplace. In winter, hands stained with hydrophobe get very cold. However, once you get the hang of it, you can cut cables almost without getting your hands dirty.
After removing the threads and dividing the bundle of modules into separate modules, each module is wiped with napkins or rags with D-Gel solvent/gasoline, and then with alcohol until clean. Although, in order to save time and get less dirty, you can proceed in the following way - initially, not completely cut the cable to the modules, but in the place where the cutting begins, 30 centimeters, without wiping anything, bite the modules (see point “e”) and pull off the entire bundle of modules with winding and threads from the fibers, holding the clean end of the cable with your hand like a handle. Your hands remain almost clean and time is saved. However, with this cutting method there is a risk of breaking some of the fibers or applying excessive tensile force to the fibers, which will negatively affect the attenuation of the fibers in the future, and there is also a greater likelihood of damaging the modules, so this method is not recommended, especially in winter time when the hydrophobic filler thickens. First you need to learn how to do it correctly, and then try different optimizations.
f) At the required length, each module (except for dummy modules, they are bitten out at the root, but first you should make sure that they really have no fibers) is bitten with a stripper for modules (suitable for copper coaxial), after which the module can be pulled off without much effort from fibers. 
Biting the modules with a stripper is a very important moment. It is necessary to choose a recess of the exact diameter, since if the recess is larger than necessary, the module will not bite enough to be easily removed; if it is smaller, there is a risk of cutting through the fibers in the module. In addition, you should carefully monitor the stripper locking pawl: if, at the moment of biting the module, it blocks the reverse movement of the stripper, fixing it in the “closed” state, then in order to separate the stripper and fold back the lock, you will have to close the tool again on the already bitten module, in this case there is a high probability that the module will be cut, which will lead to the need to re-cut the cable. We remember that when biting one of the modules, we are actively interfered with by other modules that need to be held with the other hand, and the cable itself also needs to be held suspended somehow. Therefore, at first it will be very inconvenient and you should cut the cable together.
There are cable designs where the module is single and has the form of a rigid plastic tube in the center of the cable. To remove such a module efficiently, it should be cut in a circle with a small pipe cutter (not included in NIM-25), and then carefully broken at the place of the circular mark.
When tightening the modules, make sure that all fibers are intact and not a single fiber is left sticking out of the tightened module.
If the temperature is low, the modules are thin, the cable design in the modules contains little hydrophobe (=lubricant) or the length of the removed modules is significant - the module may not be pulled off the fibers without effort. In this case, you cannot pull too hard, since stretching may affect the attenuation of the fibers in this place, even if the fibers do not break. You should bite and remove the module in 2-3 steps, in parts and slowly.
When cutting the cable, you should pay attention to the length of the fibers. It must be no less than specified in the instructions, usually 1.5-2 meters. In principle, you can cut it into 15 cm and then even somehow weld it, but then when laying the fibers in the cassette, problems will arise. big problems: a large supply of fibers is needed just so that there is room for “maneuvers” during installation, so that you can “play” with the length and beautifully lay all the fibers in the cassette.
Sometimes it becomes necessary to weld into a transit cable without cutting it. In this case, it is cut into modules just like a regular one, but the requirements for careful cutting are stricter: after all, communication can already go through the cable. It is cut down to modules and the modules are carefully inserted into the “oval” coupling input (they won’t fit into a regular round one - they will break), for this input a special set of heat shrink and metal clips with a block of hot-melt adhesive are used. This glue, when shrinking from high temperature, melts and fills the space between the two cables, ensuring tightness. Next, the module into which it is necessary to weld is cut, those fibers from it that do not need to be soldered are welded back in transit, and those that we need are welded to the “unsoldered” (branch) cable. Very rarely, a situation may arise when we need to take a fiber from a module, but we cannot cut the module (an important connection runs through it). Then applies kit for longitudinal cutting of modules: a “chamfer” is removed longitudinally from the module, the fibers are removed from it, wiped off the hydrophobe and sorted. The ones we need are cut and welded onto another cable according to the diagram, and the rest are simply placed in a cassette. In this case, if a continuous cable is installed, the length of the fibers should be twice as long (2-3 m), this is understandable.
The fibers must be clean (carefully wiped free of hydrophobe); special care should be taken to ensure that all fibers are intact. Fibers require careful handling, because in the case when the cables are cut and inserted, the welding is almost completed and some fiber breaks at the exit of the cable, you will have to re-cut the cable and weld, which will take a lot of time and is extremely undesirable and unprofitable when quickly restoring communication on an existing highway. 
Optical fibers damaged as a result of careless cable cutting (the length of the stripper blade was incorrectly set to remove the inner sheath of the cable, as a result of which the modules were cut and some of the fibers were damaged)
G) The fibers should be thoroughly wiped with lint-free wipes and alcohol to completely remove the hydrophobic filler. First, the fibers are wiped with a dry cloth, then with wipes soaked in isopropyl or ethyl alcohol. This order is special because on the first napkin there remains a huge drop of hydrophobe (alcohol is not needed here), but on the 4th-5th napkin you can already call on alcohol to dissolve the remains of the hydrophobe. The alcohol from the fibers evaporates quickly.
Used napkins (as well as scraps of cable sheath, chipped fibers and other debris) must be cleaned up after yourself - have mercy on nature!
Cleanliness of the fibers, especially towards the ends, is of great importance for quality welding. Where work is done with microns, dirt and dust are unacceptable. The fibers should be inspected for the integrity of the varnish coating, the absence of dirt, and broken parts of the fibers. If the varnish on some fiber is damaged, but has not yet broken, it is better not to risk it and recut the cable. Spend 10-15 minutes, otherwise you risk spending the whole day.
H) The cut cables are covered with special adhesive heat shrinks, which are often included in the coupling kit (if the coupling has a cable entry pipe). If the coupling provides for clamping the cable in raw rubber with sealant, then heat shrinkage is not needed. A very common and very unpleasant mistake made by a beginner is to forget to put on the heat shrink! When the coupling is welded, the heat shrink is pushed onto the coupling pipe and shrinked with a gas torch, blowtorch or industrial hair dryer, providing a hermetically sealed cable entry into the coupling and additional fixation of the cable. The most practical way to do this is with a small torch placed on a canister of tourist gas with a clamp: one canister is enough for dozens of welded couplings, it simply ignites, unlike a blowtorch, it weighs little, and there is no dependence on electricity, unlike an industrial hair dryer.
Before shrinking, the coupling pipe and the cable itself must be sanded with coarse sandpaper for better glue adhesion. If you neglect this, you may end up with a misunderstanding like this: 
If you still forgot to put on the heat shrink, a heat shrink cuff with a lock (known as XAGA) will help. Collective farming cannot be sealed with electrical tape!
Some heat shrinks (for example, from Raychem) are covered with dots of green paint, which turns black when heated, indicating that this place no longer needs to be heated, but here it should be heated some more. This was done because the heat shrink can burst if it is overheated in some place.
It is better to seat after the coupling is welded. If something goes wrong during welding (for example, the fiber breaks and you have to recut the cable), then you won’t have to pick at the hardened thick adhesive heat shrink with a knife, and the heat shrink itself won’t be wasted.
I) The cut cables are inserted into the coupling or cross-connect, fixed, and the coupling or cross-connect itself is fixed on the desktop. When fixing a cable in a coupling or in a cross-connection, you should follow the installation instructions - everything is different for different couplings. In some cases (armored cable and, for example, an MTok A1 coupling with the corresponding entry kit), fixing the cable in a coupling is a separate difficult operation with cutting the armor, winding sealant, etc.
So we have inserted the cut cable into the coupling/cross, now we need to measure and strip the fibers, put on the KDZS and cook according to the diagram. I’ll talk about this in the next part, since it’s a bit much for one article.
Optical couplings
I'll tell you a little about optical couplings and cross connects. I'll start with the couplings.An optical coupler is a plastic container into which cables are inserted and connected. Previously, in the late 90s - early 2000s, when all specialized materials for optics were in short supply with exorbitant prices, some smart guys made sewer fittings or plastic bottles. Sometimes it even worked for several years. :) Today this is certainly wild, normal couplings can be bought in any medium and large city and prices start from 1500-2000 rubles. There are many designs of couplings. The most widespread and familiar design for me personally is like that of the Svyazstroydetal series of couplings “MTOC”. There is a headband from which pipes for cable entry protrude from the outside. A metal frame is attached to the inside of the headband, to which optical cassettes are attached. A cap is placed on top (which can be made with stiffening ribs for strength), sealed with an elastic band. The cap is fixed with a detachable plastic clamp: the coupling can always be opened and closed without wasting a repair kit made from heat shrink. 
In general, Svyazstroydetal makes generally good couplings for various applications. From the MTOC series, I personally like the L6 coupling the most: it’s universal, inexpensive, and easy to install. 
There are other couplings in the MTOC series - small-sized, for sewerage, for inserting armored cables, for burying underground. For each coupling it is possible to purchase additional components and kits for cable entry: for example, cast iron armor protection for the underground coupling "MChZ", an extra set of optical cassettes with consumables, or an additional kit for inserting another cable.
If you need something cheaper, they have a series of couplings “MOG”, of which the most popular is the coupling “MOG-U” (Optical Urban Coupling, Shortened): at a price of less than 2000 rubles we get a simple and high-quality coupling, which, in fact, some believe inconvenient for installation. 
Such a coupling will not look very good on a pole, and it is inconvenient to wind up a supply of cable with such a coupling while standing on a ladder, so they are usually placed in hatches. This coupling is designed to be placed in the telephone hatch on special standard consoles. The downside of the “mogushka” is that it does not have a detachable locking clamp and to open it you will have to cut off the heat shrink, and when closing it, use a repair kit made of wide heat shrinks (if the cables are wound in at one end) or a heat shrink sleeve (if the cables are on both sides). The same applies to A-series MTOKs. In addition, if you enter cables from both sides, it is important not to forget to put on plastic pipe on one of the “sides” of the cables, otherwise you won’t be able to put it on without cutting it: this also affects beginners.
Also sometimes there are couplings without pipes, in which the cables are sealed by clamping them in damp rubber or sealant. Here, for example, is the “SNR-A” coupling, which my partner and I welded together as part of the construction of the FTTB ring. 
This method of sealing cables requires great care, since otherwise water may get into the coupling, which is undesirable. Firstly, water in the coupling can over time cause clouding of the glass fibers and deterioration of the varnish. Secondly, all kinds of metal will rust structural elements, the armor grounding wire, if any, will rot. Thirdly, Kevlar will draw water into itself. And most importantly - the coupling, full of water, in cold weather it will simply crush along with the fibers.
At least two cables are usually inserted into an optical sleeve. Of course, you can come up with a wild welding scheme, when one cable is inserted and welds on itself, but usually 2-3 cables are inserted. If 4-5 cables are inserted, and all the cables are different with different colors and different numbers of fibers in the modules, then the coupling turns out to be difficult to install and then disassemble what is soldered where. My partner and I cooked my first such coupling for 3 days! :) So it is better to design the network so that no more than 3 cables enter the coupling.
Optical crosses
The optical cross-connect is designed to terminate the cable in the place where it was connected: at the base station, in the information center, in the data center, in the server room. A typical cross-connect is a 19" metal box for mounting in a standard rack; a terminated cable is inserted into it at the back; strips with ports are located at the front.
Welded crossover for 24 ports of FC/APC type, single-unit
Welded cross-connect for 64 ports, LC type, 2-unit
Working cross-over for 96 FC ports
There is also a cheaper option - when everything that is possible is thrown out of the cross, then it turns out something like this: 
Open cross-connect for 8 SC/APC ports, 1 unit. The bad thing is that the optical pigtails are not protected in any way and can be broken by those who rummage through the box/rack, dragging, say, a new cable.
All of these crosses are rack-mounted, but there are also wall options, and other rare ones. 
Wall distribution for 16 FC ports. By the way, it is welded poorly: the yellow shells of the pigtails do not fit into the KDZS and the fibers can break, and the fibers in the cassette are laid with small bending radii
The cable inserted into the cross is welded to the so-called pig tails: in the photographs these are thin yellow laces inside the crosses. Each fiber belongs to its own pigtail. The other side of the pigtail contains an optical connector-plug, which is inserted into the optical adapter-socket from inside the cross-connect. Outside the cross-connect, switching is performed with optical patch cords (thick yellow cords). The patch cord differs from the pig tail in that it has a more durable connector and the presence of Kevlar inside, so that if someone gets caught on the patch cord and pulls, it is difficult to pull it out. Well, patch cords have connectors on both sides, while pigtails have connectors on only one side. If necessary, a temporary patch cord can be welded from two pig tails.
In principle, several cables can be inserted into a cross-connect, some of the fibers from them can be welded together, and some can be brought out to the ports. Then we get something that can be called a “cross coupling”, while we save on materials and welding. This is sometimes done when installing FTTB, but it is undesirable to do this, as the complexity of the circuit increases.
Adapters and connectors
Optical cross connects are characterized by the adapters used in them (simply - optical sockets). There are also a large number of standards and substandards.
This picture shows only part of the “genera” and “types” of optical sockets
The standard is a complex of an adapter (socket) and a connector (plug). Of course, there are adapters between different standards, but these are crutches that are only suitable for measurements and should be avoided in a constantly working communication line. The fewer welded and especially mechanical connections in the line, the better. Of course, if the distance is small, the line will work, even if a couple of decibels are lost on some of the crosses. In the case of short lines, optical attenuators are sometimes specially installed. But for very long lines, where the equipment is operating at its limit, adding another cross-connect or coupling (that is, some 0.05-0.1 dB of loss) can be fatal: the line will not rise.
The tip of the “fork” is, roughly speaking, a cylinder with a thin through hole for the fiber in the center. The end of this cylinder is not flat, but slightly convex. The tip consists of an incredibly hard and scratch-resistant cermet, although metal ones are very rare. There are rumors of people breaking side cutters trying to cut through this tip. :) I myself easily scratched steel and glass with these tips. Nevertheless, they must be handled with care, do not allow dust to enter, do not touch the end of the connectors with your finger, and if you touch them, wipe them with a cloth soaked in alcohol. Ideally, a special microscope (optical or with a camera) is used to monitor the condition of the patch cords. Dirty - clean, scratched, if the scratch crosses the center with the glued fiber - scrap or polish. Dirty and scratched sockets and patch cords are a common cause of line attenuation.
The optical fiber is fixed in the tip by gluing it with epoxy (or some other) glue and subsequent grinding on a special machine, although this is only done if you need to make long non-standard patch cords: it’s easier and cheaper to buy ready-made ones. The price of a regular optical patch cord 2 meters long is about 200-400 rubles. 
Manufacturing of patch cords. Emilink
In practice, standards such as FC, SC, LC are most often used. Less common are FC/APC, SC/APC, ST. LC can be either duplex or single.
F.C.
Pros - excellent connection quality, therefore suitable for critical highways. An old proven standard. Metal (hard to break). If you move a well-screwed connector with your hand, this will not affect the connection.
Cons: It takes a long time to unscrew/tighten when switching. If they are located closely on the cross, it can be very inconvenient to crawl up to unscrew one of the connectors in a crowd of others.
The connector itself is fixed motionless thanks to the groove on it and the notch on the adapter, and only the knurled nut turns with your fingers.
S.C.
Everything is the same as in FC, only the adapter and connector are square, plastic, and the connector is fixed by clicking, not screwing. Pros - cheaper than FC, more convenient and faster to switch, cons - plastic is easier to break, shorter connection and disconnection life. It sometimes happens that the amount of reflection and attenuation on a connection changes noticeably after touching the connected connector, which is undesirable for critical lines. The color of the connectors is usually blue.
LC and LC Duplex
They have similar properties to SC, but have much smaller dimensions: a two-unit cross-connect on an LC accommodates as many as 64 ports, and on an SC - only 32. Due to their small dimensions, they are often mounted directly on optical multiplexer boards.
FC/APC, SC/APC, LC/APC
The same as FC, SC and LC, but with an oblique (A - angle, angle) tip polishing.
Difference between ceramic ferrules with regular and bevel polishing. The image is a little inaccurate: in fact, in the case of both polishings, the ends are not flat, but slightly convex; accordingly, when connecting, only the centers of the tips, where the fiber is, will touch.
Such adapters and connectors are made Green colour and when compared with conventional UPC (or simply PC) polishing, the difference is visible to the eye. This is necessary to reduce back reflection at the junction of two connectors. As far as I know, this type of polishing was developed for transmitting analog television via optics to avoid ghosting on the screen, but I could be wrong.
It is possible to combine “regular” and “oblique” polishing with each other, but only if it is necessary to take a reflectogram according to the principle “if only the length of the path can be seen”: a large air gap will lead to strong losses and strong back reflection.
My story is over for today. Ask questions, I will try to answer. If you find this topic interesting, I will write a continuation.
Sleeve for welding fiber optic connection: KDZS
Despite its apparent simplicity, it is a rather complex and, in its own way, irreplaceable detail. Designed to protect and seal the welding site and the fiber area cleared of varnish. Consists of three components.
- Metal core. It serves as a rigid frame and prevents the sleeve from “warping” in the stove, distributing the heat evenly.
- Hot melt adhesive. Fixes the fiber after cooling and seals the joint.
- Heat shrink tube. It is compressed in the oven, forming an external protection for the connection.
Sleeve with HERE for protection of welding joint OV (KDZS)
Enlarge photos
In their original state, they are a tube 3 to 6 cm long. The fiber is inserted into the sleeve before welding. After welding and checking the joint with a reflectometer, the sleeve is moved to the joint and placed in the oven of the casing device.
Can be supplied complete with coupling.
12.27.13 Information supplemented with the page Fiber optic sleeves - KDZS
Laying OM in a splice plate (cassette)
Laying optical fibers in a cassette (fiber organizer or splice plate)
The welded fiber together with the sleeve cased at the joint looks like a thin fishing line with a weight-sleeve in the middle. To carefully secure such a “web” in all optical couplings and terminal cross-connects, a special box is used, somewhat similar to a VCR cassette. People often call this box a cassette, but there is also official name— light guide organizer (splice plate). Cassettes (splice plates) for laying optical fiber sometimes differ slightly in design, but as a rule they contain cells for attaching sleeves and some space for laying out cable fibers or optical cords. Photos of various cassettes:
Cassette (fiber organizer or splice plate)
for laying optical fiber in the distribution box. Red inserts for attaching sleeves
A cassette with laid optical fiber in the optical cross box.
The sleeves are not only placed in the cells, but also secured with a special fastener
Fiber optic cassette for installation in a coupling
Sequence of assembly of couplings and terminal devices of fiber-optic communication lines
Installation technology for fiber optic couplings and termination devices
Couplings and fiber optic cross-connects have different shape and correspondingly, different sequence assemblies. As a rule, suppliers or manufacturers include installation instructions in each coupling. In terms of design, I will only note that some types of couplings remain partially dismountable after final installation (clip-latch) or are completely welded.
1. Start with pruning. According to old, perhaps unwritten rules, 2 meters of cable is simply cut off. This is due to the fact that when tightening, the end of the cable experiences a maximum of impacts and kinks; moreover, if the sheath is broken, water could get inside the module, which would subsequently cause clouding of the fiber glass.
2. Cable reserves are left on the fiber-optic coupling, the purpose of which is to replace or remake the coupling. Its length has changed over the years (initially 15 meters, now less). On intercity lines, everything is documented, see protocol forms. Much of this stage can be specified by the customer or written down in the project. Sometimes a much larger reserve may be left due to the peculiarities of cable disposal in construction organizations communications.
Optical fiber in modules
(4 pieces each)
3. The protective sheaths are removed from the cable for a length of about 1 meter, up to the optical modules, only a certain section of the armor is left for its fixation and electrical connection. Optical modules are wiped with nefras or alcohol to remove any remaining hydrophobic filler.
4. Partially cut ends are inserted into the holes of the coupling or cross and secured. In cross-connections, the armor is connected to a soft wire and brought out to the ground terminal of the rack. Secure the cassette.
5. Next, usually with a special clothespin-knife, the shell of the optical module is cut off so that the ends of the module shell are secured in the cassette clamps. The fibers are also wiped with nefras.
Fiber optic coupling installation stage
7. A heat-shrinkable sleeve KDZS is put on one of the fibers to be welded.
8. Next, a tool called a striper comes into action. They remove the varnish from the ends of the optical fiber by about 2 - 3 cm (under the cleaver).
9. The cleaned optical fiber is wiped with alcohol or a special cloth and placed in a cleaver, and the fiber is cleaved.
10. The welding process is described on the welding page. The welding joint is measured and controlled using an optical reflectometer.
11. The fiber optic sleeve is encased.
12. The welded fibers are placed in a cassette (light guide organizer or splice plate).
Fiber optic cassette with laid fibers
13. Points 7 to 12 are repeated for the remaining optical fibers.
14. After casing and laying all fibers, control with a reflectometer is carried out again.
15. For the coupling, everything is sealed and placed in a pit (well). For cross laying and connecting connectors.
Official installation procedure fiber optic cable
revealed on the pages
12.6 Installation of optical couplings(Manual for the construction of linear structures of local communication networks, M., 2005)
10.3 Laying optical cables from (Manual for the operation of line-cable structures of local communication networks)
Information on the organization of terminal devices is also available on the pages of the book "Fiber optics. Theory and practice" - Connection panels, connection devices and terminal compartments. Covering connections
Coupling installation instructions:
Short fiber optic coupling MOGU
Dead-end fiber optic coupling MTOC
Good afternoon, optical cross-connects BON produced by STC "PIK" look like this:
BON equipment:
Approximate configuration of BON in the figure:
Rules for installing and assembling BON:
1 After opening the package, check the external condition assembly units and parts of the optical box, as well as the presence of all accessories according to the delivery set.
2 Secure the box to the wall using screws or anchor bolts from the delivery kit, having previously made markings along the holes on the back wall of the BON.
3 Option for preparing the main cable for entry into the BON.
3.1 Wipe the outer shell of the optical cable with a rag over a length of 2.0 m. Cut the cable in accordance with Figure 1a.
3.2 At a distance of 1500 mm from the end, make a circular shape on the cable sheath incision Using a special tool along the entire marked length of the cable endmake a longitudinal cut and remove the shell. Remove the armor from the cable, leaving 30 mm.
3.3 Take a PRPPM 1×2 wire 250-300 mm long, free it from the insulation at the end at a length of 60-70 mm, tin it and apply a bandage to the stripped and tinned section of the steel cable sheath (armor). Then solder the bandage with POSS 30-2 solder. On top of the wire bandage, over the entire section of the steel shell, wrap two layers of insulating tape with a 50% overlap.
3.4 Make circular and longitudinal cuts on the inner sheath of the cable. Make a longitudinal incision with a special tool. Next, remove the inner sheath from the cable core.
3.5 Wipe the modules and CSE with liquid to remove hydrophobic filling and dry rags.
3.6 If the optical cable has an armored cover made of galvanized steel wires, cut in the following sequence in accordance with Figure 1b:
- Using a utility knife, make a circular cut in the outer sheath of the optical cable at a distance of 1.5 m from the end of the optical cable, then make a longitudinal cut in the sheath of the optical cable from the end of the optical cable to the circular cut;
- remove the outer sheath of the optical cable;
- untwist the twisted steel wires;
- cut off the excess length of the wires with side cutters or cable cutters;
- then carry out actions in accordance with clauses 4.3-4.3.5.
3.7 If there are water-blocking tapes and threads in the OK design, remove them flush with the edge of the inner shell. Remove hydrophobic filler,using a rag and D-Gel.
3.8 If the OK design contains synthetic (aramid) threads, cut them at a distance of 150 mm from the edge of the outer shell (see Figure 1a) with scissors for cutting synthetic threads, and fasten the ends of the threads with insulating tape.
3.9 Remove the cord fillers of the OK core (if any) using side pliers.
You may also be interested in: “How to choose the capacity of a linear cross-connect when building a GPON network?”
4 Installation of BON cable.
4.1 Insert the end of the prepared optical cable through special holes in BON, cut to required length central power element, remove the plastic shell (if any) and secure it with a strip with two screws. If the optical cable has aramid threads, secure them together with the central power element and remove the excess length. To enter the cable into the BON-72S, make a cross-shaped cut in the rubber plug with a knife. In BON-72SP, at the cable entry point, install a pipe of the required diameter from the delivery kit (the pipe must go outside, and in the transport position the pipes are installed inside the cabinet).
4.2 Secure the sheath of the fiber optic cable cable ties on the box body at the cable entry point. In BON-72S, a metal clamp is also provided for fastening the input cable. Ground the optical cable by connecting the shielding wire to the grounding pin on the wall of the box.
4.3 Lay out the optical cable modules inside the BON. Determine the required length to the point of fixation in the cassette, remove the excess length of the optical module. Wipe optical modules and each optical fiber with isopropyl alcohol (2-propanol) and lint-free wipes.
4.4 Mark the modules with self-adhesive markers. The marking of the modules must correspond to the marking of the fibers of the optical boreholes.
4.5 Collect the inserted optical modules into a bundle and secure the bundle with cable ties at the entrance to the splice cassette. Work should begin from the bottom splice cassette.
4.6 Prepare the fiber to be mounted for welding in accordance with the instructions attached to welding machine. Use a stripper to remove the protective sheath of the optical fiber. Place KDZS sleeves on the ends of the OB.
4.7 Using an optical fiber splicing machine, connect the optical mounting cords (pigtails and fibers of the cable being mounted. When working, follow the operating instructions for the splicing machine.
4.8 Verify the integrity of the welded joint using a reflectometer.
4.9 Protect the welded joint using a KDZS sleeve. It is prohibited to use a KDZS sleeve to protect more than one optical fiber welded joint!!!
4.10 After the sleeves have cooled, install the welded joint in seat splice cassette holder. Place stocks of spliced optical fibers inside the splice cassette.
4.11 Place modules and pigtails inside the BON. Make sure there is no tension on the fibers. Enter the necessary data in the plate to indicate the fiber crossing addresses on the cover of the splice cassette.
Safety requirements:
When performing installation and installation work, you should be guided by the requirements of the “Labor safety rules when working on linear structures of cable transmission lines” POT RO-45-009-2003.
When cutting optical cable and its waste, special containers should be used. It is not allowed for pieces of optical fiber to come into contact with the assembly table, the floor, or the clothes of installers, as this can lead to injury to unprotected areas of the skin during work and when cleaning the workplace.
To avoid damage to vision, visual or optical inspection of the end of the optical connector through which the optical signal is transmitted is prohibited.
When working with optical connectors, you should take precautions to prevent deformation and avoid bending the cable with a radius less than that allowed by the cable specifications. The static bending radius of cords during installation and operation must be at least 40 mm, for multicore optical cables - at least 20 cable diameters.
To prevent injury, installers must be provided with by individual means protection (safety glasses in accordance with GOST 12.4.013-85 and special clothing).
8.1 ODF is included in the PON exchange section. ODF must have the following capabilities:
− providing free access to any of the optical ports and the ability to quickly perform cross-connection work;
− increasing the cross-connection capacity during operation;
− ensuring prompt installation, installation and switching of optical fibers;
− system for laying fiber optics and patch cords, guaranteeing compliance with the requirements for the bending geometry of fiber optics;
− constructively support the installation of splitters directly in the ODF;
− occupy a minimum area.
The cross must match " Technical requirements to high-density station optical cross-connections”, approved by the Chief Technical Director of Kazakhtelecom JSC.
Basic principle of high density ODF installation modular design consists of cutting the optical station and line cables (fibers) supplied to the cross-connect onto the mounting modular tubes, through the adapter devices shown in Figure 19.
Figure 19 Figure 20
Mounting modular tubes with 12 or 16 optical fibers are fed to the splicing and switching module shown in Figure 20, where the fibers are boiled into factory-prepared picktails. Welded fiber joints reinforced with KDZS sleeves are placed in cassettes. The design of the optical cross-connect should ensure the extension of the splicing and switching module from modular blocks to a length of up to 1.5 meters due to the supply of mounting modular tubes laid in the switching and splicing module, only when installing (unbonding) optical fibers of station and linear fiber optics. SC/APC type connecting sockets are installed in special sockets of patch panels.
8.2 Due to the large number of optical distributions of various designs, including top or bottom feed of the fiber optic cable from a cable rack or through a raised floor, a detailed description of the installation is not advisable; in each specific case, the manufacturer’s instructions should be used. The length of the supply of linear cable fibers and picktails left on the cassette in the terminal device must be at least 0.5 m, and the length of the fiber supply left on the cable rack or in the raised floor is at least 2 m. Placement options are shown in Appendix 3.
NOTE For any optical cross-connect design, station cables or station patch cords must be fed to station splicing and switching modules installed in the upper part of the cabinet, in the middle part of the cabinet it is necessary to install splitter modules with input and output splitters welded into connectors (optical switching ports), and onto linear modules installed in the lower part of the cabinet, it is necessary to supply main linear fiber optic cables. There are 2 options for mounting (feeding) OLT linear terminations to the optical cross-connect:
When installing an OLT in a combined room in close proximity to the ODF and the capacity of a GPON network node for up to 2 thousand subscribers, the OLT outputs can be connected directly to the ODF trunk ports using patch cords of the appropriate length;
When installing an OLT in a containment zone and the capacity of a GPON network node exceeds 2 thousand subscribers, the connection of the OLT outputs to the ODF station ports must be carried out using 3-meter pigtails terminated on the OLT side with 48-96 station cables, and on the ODF side the station cable must be inserted and welded into station splicing and switching modules. In the latter option, switching of OLT outputs with any port of a linear trunk cable should be carried out using short patch cords inside the ODF rack between the linear and station ports of the optical cross-connect.
8.3 Inside the premises of the telephone exchange, up to the terminal cable equipment ODF should be laid OK with a non-flammable sheath. The margin for cutting the optical station cable from the station and linear parts of the cross-connect must be at least 3-3 meters.
Optical cross connectors are used to enter the optical cable and connect station equipment to the line. To implement a fiber-optic communication line construction project, it is necessary to select the brand and capacity of the optical cross-connector. For the end points of the designed fiber-optic line at the Zhetygen station and the Korgas station, the required number of sockets in the cross-connection is 16. At the intermediate points Kurozek station and Shelek station, where two cables are installed, 32 sockets are needed. These requirements are met by optical cross-connectors of the PR-16 type produced by JSC 2ASystem, Tula. One cross-connect is installed at the end points, two at intermediate points (sides A and B), a total of 6 optical cross-connects are required.
Since optical pigtails are ordered separately, we will choose standard pigtails 1 m long. with FS type connectors (accordingly, the optical cross-connector will also be equipped with FS type connectors).
Optical cross (Fiber Cross) Distribution panel PR 16
General information.
Optical cross (Fiber Cross) distribution panel PR 16 provides:
- - Input, placement, fastening and storage of stock of station and line cables;
- - Termination, connection, switching of line and station cables with optical fibers in the communication network common use, in technological communication networks and special-purpose communication networks;
- - Connection of control and measuring equipment;
- - Possibility of marking linear and station circuits.
Technical characteristics of the optical crossover.
The maximum number of incoming linear fiber optic cables is 4 pcs.
The maximum number of optical connecting sockets on the panel is 16 pcs.
Overall dimensions of the Optical Cross (Fiber Cross) PR 16 - 484 x 280 x 44mm
The weight of the Fiber Cross distribution panel PR 16 is 2.4 kg.
Type of optical ports - FC, SC, ST, FC/APC, SC/APC
Optical crossover delivery set.
Optical cross (Fiber Cross) distribution panel PR 16 is equipped according to table 3.3
Table 3.3 - Optical crossover delivery set
|
Name |
Quantity, pcs. |
|
|
Distribution panel |
||
|
Splice plate |
||
|
Screw-washer-nut set |
1 (supplied by agreement) |
|
|
Screed 80mm |
||
|
Screed 140mm |
||
|
Organizer platforms |
||
|
By number of ports |
||
|
Passport products |
Notes
It is allowed to replace the products included in the delivery set with similar others that do not impair the presentation, performance characteristics and comply with safety requirements.
Delivered as agreed with the customer
Optical crossover safety requirements.
Before starting work, carefully study this passport.
The optical cross-connect must be used in accordance with the purpose specified in the passport.
Optical cross device (Fiber Cross) PR 16.
The optical cross is metal box, painted using powder coating technology, which provides reliable protection against external influences. Inside the optical cross there is a splice cassette (splice plate) for laying sleeves and a supply of fibers (it is possible to place 24 fibers on one splice cassette)
The optical cross-connect has four holes for optical cable input/output. The holes are closed with rubber plugs for protection. internal space optical cross from dust; when installing an optical cable (OK) in PR 16, you can select one of four holes for OK input (or use all four if necessary).
Installation instructions for optical cross (Fiber Cross) PR 16
Removing the packaging - be careful not to damage the optical cross-connect with the tool. After opening the package, check the external condition of the assembly units and parts of the optical crossover, as well as the presence of all accessories according to the packing list.
Preparation for installation
Before you begin installing the OK, make sure that the mounting brackets on the right and left sides of the optical cross-connect are firmly secured;
Place the Fiber Cross PR 16 on the desktop for mounting OK.
Figure 3.10 - General view of the distribution panel Fiber Cross PR 16 (in the photo without the top cover with FC connectors).
Cable cutting and entry
Cut the cable in accordance with Figure 6.14.
Insert the cable into the Fiber Cross PR 16 through the hole, cutting the rubber membrane.
Secure the OK using the ties included in the kit. Secure the central power element using a bracket and screws as shown in Figure 3.12.
Place heat shrink sleeves onto the pigtails.
Figure 3.12 - Optical cable input
Works with optical fiber.
Strip fibers and weld in accordance with the recommendations for the welding equipment used;
Number the modules of the cable being installed;
Number the pigtails and weld them with the corresponding fibers;
Bake heat-shrinkable sleeves (heat-shrinkable sleeves are included);
Place the sleeves and fiber stocks in the cassette according to Figure 3.14, 3.15. (drawings of cable module insertion and pigtail placement are spaced for ease of reading).
When laying stocks of cable fibers, sleeves and pigtails, ensure that the bending radius of the fibers and pigtails does not exceed 30 mm
Close the splice cassette with a transparent lid.
Connect the pigtails to the adapters according to their numbers.
Figure 3.13 - Input of cable modules
Figure 3.14 - Layout of pigtails
Rack mounting.
The optical cross (Fiber Cross) distribution panel PR 16 is secured in a 19-inch rack with four M 6 screws (fastening screws are not included in the delivery package). Lay and secure the cable supply in a convenient place.
To assess the quality of installation of the optical cross-connect, reflectograms of each OF in the regeneration section are taken. If optical attenuation is normal and there are no defects in the welded joints, the station equipment is connected to the line using patch cords.
Table 3.4 - Organization of jumpers on the optical cross-connect of the Kurozek station access node
At all communication points on optical cross-connections, 1-4 optical fibers are switched to Huawei OptiX OSN 1500B equipment. A linear path is organized along 1-2 OBs for the operation of a digital transmission system; 3-4 OBs are also connected to digital equipment and are used for automatic reservation of the linear path.
