FDT 288 for FTTH Network : Wonderfully explained

FDT 288 for FTTH Network : Today, in this article, I will explain that what the major role of FDT 288 in FTTH network. People who are working on FTTH Network can understand very well how much FDT is important in FTTH network. Most of the telecom industry starts the first work in FTTH construction from the FDT installation, Only after the installation of FDT, the remaining work of the FTTH begins and this is also the right way. But today we are specifically talking about FDT 288.

I want to tell you in brief that the FDT shall be used to accommodate and provide optical termination point between the feeder and distribution network with flexibility of cross-connection. FDT 288 means with maximum fiber capacity of 288. May be used FDT 288 with initial capacity of 4 or 6 splitter units; or with full capacity of 8 splitter units.

FDT 288 details

FDT 288 Functional Layout

Technical Requirement of FDT 288

All components of the FDT described in this specification shall be of high quality design and workmanship, and simple to install. The FDT shall be sturdy and impact-resistant against damage during placing or installation operations.

The shell, door and base of the cabinet shall be of non-metallic materials and must be solvent and stress crack resistant and be compatible with other FDT materials. The cabinet shall be designed and constructed to be suitable for outdoor installation. It shall be dust proof, splash watertight, weatherproof, and prevent corrosion to the hardware contained within.

All metallic parts of the cabinet shall be stainless steel or materials suitably protected against corrosion. There shall be no possibility of galvanic corrosion effects between any of the metallic components.

The FDT shall not have any sharp edges or other defects that may be injurious to personnel or potentially damaging to other components and materials used in the FDT. The surface finish of the FDT shell, base and door shall be reasonably consistent. No glass fiber shall be visible on the surface.

The FDT shall be efficiently designed so that the optic cables, patch cords and pigtails shall be able to be easily handled and managed during termination, splicing, routing, securing and storage. All materials used in the cabinet shall be non-toxic and dermatologically safe. 

Design Requirement of FDT 288

The cabinet shall be designed and have provisions for major components-
Cabinet Shell, Cabinet Door, Door’s Key & Locking System, Mounting Frame & Bracket, Optical Splitter Frame (OSF),1:32 or 2:32, Bypass Patch Panel, Splice Shelf (Feeder & Distribution Cables), Splice tray, Adapter (Through-Connector), Pigtail configuration, Base Plate, Cable Clamp Hardware, Earthing System, Elastomeric Seals, Splice Protection Sleeve, Protective Tube Set.

Cabinet Shell of FDT 288

Material used for cabinet shell of FDT 288 is Glass fiber reinforced polyester or polycarbonate. Generally color of finished surface is grey.

Outer dimensions of FDT 288 without base will be Width- 750 mm, Height- 1100 mm, Depth- 320 mm.

Assembly (Full Front Access) : All FDT cabinets shall be designed for full front access. FDT 288 arranged side by side, with appropriate markings and labelings. Shell shall consist of replaceable parts, two side panels, rear panel, door frame and roof. Roof surfaces shall slope down on all sides.Shell shall be easily detachable from the base and frame. Shell shall allow ventilation of the interior.

Cabinet Door of FDT 288

Material used for cabinet door is Glass fiber reinforced polyester or polycarbonate. Door color will be grey, and single door type will be used for the FDT 288. 

Door assembly: Door for FDT288 shall swing to open from left to right and Continuous hinges, equipped with removable steel pin. Document holder also available in the door that shall be transparent and permanently fixed on the inside surface of each door of the cabinet’s.

Door stay mechanism: Shall limit the door opening angle to approx. 100° minimum and shall secure the door in open position.

Telecom industry logo marking: Molded or permanently printed on the door (top of the outside surface) with following dimensions: Height : 15 cm, Length : 25 cm.

Manufacturers logo: Molded or printed on the inside surface of the door or shell.

Door’s Key & Locking System

Material of key and lock: Hexagonal Key: Nickel plated Chrome-Vanadium- Steel, Lock’s cylinder: Chrome plated Non-corrosive steel or solid extruded brass. Lock’s center pin shaft: Chrome plated Steel, cold formed.

Type of Door Lock: Latch-type cylindrical lock, with recessed non-metallic handle type (flip & twist to open) to be used by telecom industry standard hexagonal key wrench.

Location of Door Lock: Each door with a single lock at center with mechanism that open latches on top and bottom; or one lock for each latch at the upper and lower side of the door.

Type of Key: standard hexagonal key wrench of 8.0 mm between the flats, with a 5mm dia. hole of 15mm in depth.

Mounting Frame & Bracket

Material used for Mounting Frame & Bracket is electrically conductive sheet metal.

Construction: Shall be based on standard metric ETSI or 19 inch rack. It Shall secure the OSF, ODF, cable/cords guide support rails and bracket. It Shall be fixed onto the base plate and/or shell by bolts.

Cable routing hardware shall be fixed in the left and right side of the mounting frame. All parts of mounting frame shall be fixed with clear distance from the inside surface of the door. Cable clamp shall be fixed at the lower part of the mounting frame.

Optical Splitter Frame (OSF), 1:32 or 2:32

Material used Cold-rolled carbon steel sheets of commercial quality, 

Shelf (housing): Shelf Shall be designed with built-in front brackets to arrange and hold incoming and outgoing pigtails. It Shall be fixed onto the mounting frame by bolts.

Door or cover: Shall be swing-down to open and flip up to close on the input and output ports of the fiber termination module.Door shall be equipped with one latch-type locking

mechanism. No key is required.

Marking of OSF door or cover: The door shall be marked with- OSF _ (1 : 32) _ Splitter Sequence Number, 

Fiber termination panel : It Shall be swing-out or sliding (drawer) types to allow easy access to the rear and interior of the panel. The panel shall be design to accommodate 2 inputs and 32 outputs of LC/APC adapters. 

Each adapter for splitter input shall be numbered in sequence of 1 to 2, Each adapter for splitter output shall be numbered in sequence of 1 to 32, The height of the numbers shall be 5 mm (maximum). All points in the fiber path shall maintain a maximum bend radius of 30 mm.

Number of OSF for each size of cabinets: 8 OSF shelves for FDT 288 and some shelves can be supplied without Splitter Units to match the FDT initial capacity of 4 or 6 Splitter Units. 

Splitter type: Planar Lightwave Circuit (PLC), 1:32 or 2:32.

Bypass Patch Panel

Material used for Bypass Patch Panel Cold-rolled carbon steel sheets of commercial quality, 

Shelf (housing): Shall be design with built-in brackets to arrange and hold incoming pigtails from feeder splice trays and outgoing pigtails to distribution trays. It Shall be fixed onto the mounting frame by bolts.

Door or cover: Door cover shall be swing-down to open and flip up to close on the patch panel (plate) and splice trays. Door shall be equipped with one latch-type locking

mechanism. No key is required. Cover of bypass panel shall be colored in red.

Bypass patch panel (plate): It shall be swing-out or sliding (drawer) types to allow easy access to the rear and interior of the ODF. The front plate shall be designed to accommodate a minimum of 32 adapters of LC/APC type for each patch panel.

Each adapter shall be numbered in sequence of 1 to 32 for for each patch panel. The height of the numbers shall be 5 mm (maximum). All points in the fibre path shall maintain a maximum bend radius of 30 mm.

Splice Shelf (Feeder & Distribution Cables)

Material used for splice shelf is Cold-rolled carbon steel sheets of commercial quality. And Shelf (Housing) Shall be design with built-in brackets to arrange and hold incoming pigtails and outgoing distribution cables. It shall be fixed onto the mounting frame by bolts.

Door or cover: Door or cover shall be swing-down to open and flip up to close on the splice trays. Door shall be equipped with one latch-type locking mechanism. No key is requiring.

Splice tray

Material used for splice tray is High quality plastic or corrosion-free metal plate. Splice capacity is 24 fusion-spliced fibers each tray, minimum. Type of splice holder are used Snap-on types, for heat-shrink splice protectors. 

Fiber length storage capacity is Coil of 1200 mm, minimum, each fiber. Fiber bend radius inside tray can be consider 30 mm radius, maximum.

Assembly: Each tray shall be equipped with internal fiber bend control mechanism to secure buffered fibers and keep excess fiber lengths in neat coils.

Mounting of trays: Each splice tray shall be removable to allow off-rack splicing. Splice trays shall be mounted on pull-out, swing out or Sliding out type drawers.

Adapter (Through-Connector)

Type of adapters used LC/APC simplex or duplex adapters, green in color. It Insertion loss to be considered 0.1 dB (average). Material used for housing is Plastic or other approved equivalent material.

Mounting system of adapter: LC adapter couplings shall be fixed by snap-in clamp or locking mechanism, or using 2 screws with an M2 thread.

Pigtail: Pigtail inside OSF shall be 0.9 mm tight buffered cords with numbered connectors; Pre-fabricated with the splitter units, with red in cord color for splitter input and blue for splitter outputs.

Earthing System

Earthing Terminals for Cable Sheaths: Plug connector-type or screw-type terminals, to be fixed at the bottom rail of the frame above the base plate. The terminals shall accommodate 3 mm diameter earthing wires.

Main Earthing Terminal: Screw-type terminal to accommodate 6 mm diameter earthing strand, for connecting the cabinet frame to the earthing rod.

Packing of FDT 288

Each FDT and its accessories shall be packed such that all components for a complete unit meet the installation requirements. All components of the FDT and accessories shall be provided as a complete assembly and as one packaged unit, as follows:

➤The FDT shall be completely assembled (ready to install) with the following components:

➥ FDT shell or housing.
➥ Door, equipped with latch-type locking system, and identification markings.
➥Mounting brackets complete with fixing bolts and nuts.
➥OSF complete with Adapters and splitter with 1:32 (or 2:32) split ratio and external pigtails.
➥ Bypass Patch Panel, complete with adapters, pigtails and splice trays.
➥ Feeder and Distribution Splice Shelves, complete with required number of splice trays.
➥ Numbering labels for each adapter position.
➥ Labeling card attached on the inner surface of the door.
➥ Cable clamp hardware.
➥ Fiber guide mechanism.

➤Accessories

➥ Number of required fusion splice protection sleeve including spares.
➥Number of required protective tube set, per splice trays.
➥ Number of required Adapter cap for stand by adapters including spares.

Each fully assembled FDT and its accessories shall be covered with a protective plastic to protect the cabinet shell and components from scratching or damage during shipping, handling or storage, prior to placing the items into the packing carton.