CommScope FOSC450 C User manual

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© 2023 CommScope, Inc. All Rights Reserved
Contents
Installation Instructions
FOSC450 C AND D CLOSURES
F573
Rev C, April 2023
www.commscope.com
1 General product information
FOSC450 C and D ber optic splice closures, use compressed gel cable seals to environmentally seal ber cable splice points.
Both C and D closures share the same base which allows 6 cable entry ports. Size D however comes with a longer dome
allowing a size-D tray to be used which has more splicing capacity.
Tray type / closure C Closure D Closure
Tall basket Standard
basket
No basket Tall basket Standard
basket
No basket
Number of single height unit splice trays 568568
Number of double height unit splice trays 2 3 4 2 3 4
Number of single splices (stranded ber) with
SM6 Modules
60 72 96 180 216 288
Number of single splices (stranded ber) with
SM12 Modules
120 144 192 360 432 576
Number of mass fusion splices using single
height trays for rollable ribbon
720 864 NA 2160 2592 NA
Number of mass fusion splices using double
height trays for rollable ribbon or at matrix
ribbon
432 648 NA 1152 1728 NA
Table above shows splicing capacity of FOSC450 C and D closures. Splicing capacity depend on tray type, slack storage
basket, and whether ribbon bers or stranded are used.
The standard basket is the standard size for buer tube storage and provides a proportioned balance between splice capacity
and slack storage. For applications requiring more splice capacity, a exible sock or tray backbone may be used in place of
the basket to maximize splicing capacity. For applications requiring more buer tube storage, such as mid-span applications,
tall baskets may be used to maximize slack storage.
Splicing trays are either single height or double height. Double height trays are deeper trays allowing storage of at matrix
ribbon within the tray. Single height trays can be used for at ribbon, but slack ber should be pulled back and stored in the
basket and shouldn’t be stored within the tray.
1 General product information..................................................... 1
2 Kit contents.................................................................................. 2
3 Other Accessory Kits (Sold separately)..................................... 2
4 Warnings and Cautions .............................................................. 2
5 Closure entry ............................................................................... 3
6 Base removal ............................................................................... 3
7 Cable preparation ....................................................................... 3
7.1 Table cable cut length ................................................................................... 4
7.2 Loose Buer Tube cable ................................................................................ 4
7.3 Ribbon cable .................................................................................................... 4
8 Cable installation ........................................................................ 4
9 Routing fibers to the splice tray................................................ 7
10 Gel Block Installation................................................................ 10
11 Flash Test ................................................................................... 13
12 Re-entry ..................................................................................... 13
13 Adding cables............................................................................ 13
14 Disclaimer ................................................................................. 13
15 Contact information ................................................................. 13

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© 2023 CommScope, Inc. All Rights Reserved
2 Kit contents
• Dome and clamp
• Base and O-ring
• Gel block
• Hook and loop fastener strap
• 4 Gel block plugs
• Small tie wraps
• LBT (loose buer tube) friction tape
• Transportation tubes
• Slack storage basket*
• Cable strain relief kits*
• AWG10 Ground wire with alligator bond clamp (3” long)*
• AWG6 stranded ground wire with eyelets and nut to connect to feed through lug (3” long)*
• Loose buer tube storage sock (used with no basket option)*
* Quantity depends on part number conguration
3 Other Accessory Kits (Sold separately)
• FOSC-ACC-C Tray 12 and 24 (Extra tray kits)
• FOSC-ACC-C/Basket
• FOSC-ACC-D Tray 36, 48 or 72 (Extra tray kits)
• FOSC-ACC-D-TRAY-RIBN-24
• FOSC-ACC-D-TRAY-RIBN-48
• FOSC-ACC-D/Basket
• FOSC-ACC-12CA-12GNDLARGESUB-KIT
• FOSC-ACC-12CA-12GNDSMALLSUB-KIT
• FOSC-ACC-TECHFLEX Sleeving kit
• FOSC-ACC-BRDSLV-1/4-125
• FOSC-ACC-BRDSLV-3/8-125
• FOSC-ACC-BRDSLV-1/2-125
Refer to FOSC 450 Ordering Guide for complete list of accessories and their description
4 Warnings and Cautions
4.1 Follow the installation instruction steps to ensure the performance of the closure. It is necessary to take precautions
and keep the working space clean to protect the closure sealing materials and splices.
4.2 Exposure to laser radiation can seriously damage the retina of the eye. Do not look into the ends of any optical
ber. Do not assume the laser power is turned o or that the ber is disconnected at the other end. Looking into
the ends of any optical ber is entirely at your own risk. A protective cap or hood MUST be immediately placed
over any radiating adapter or optical ber connector to avoid the potential of dangerous amounts of radiation
exposure. This practice also prevents dirt particles from entering the connector and adapter.
4.3 Fiber optic cables may be damaged if bent or curved to a radius that is less than the recommended minimum
bend radius. Always observe the recommended bend radius limit when installing ber optic cables and patch
cords.

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© 2023 CommScope, Inc. All Rights Reserved
5 Closure entry
To remove the dome from the closure, release the clamp handle. Slight pressure applied to the side of the handle will dis-
engage the locking tab. Hook the handle on the two posts, and pull back until the clamp releases from the closure. Keep the
O-ring, clamp, and dome clean and dry (Figure 1).
6 Base removal
Loosen the four bolts and swing the washer out of the way to remove the star bracket from the FOSC 450 closure base
(Figure 2).
Important: Bring all cables that are to be spliced through the base before proceeding to the next step. Slide the base over
the cables and out of the way.
7 Cable preparation
Important: Small round or at cable installations -- If cables are less than 0.35” in diameter or at drop style, an additional
step is required for cable sealing in the port. In this case the cable diameter must be built up to the minimum 0.35” diameter.
In addition, if multiple small cables like these are to be installed in a single port, it is imperative that gel is applied between
the cables before installing them into the gel port. See FOSC 450 drop sealing kits installation instructions for further details.
Cable combinations in multi-drop kits and single cables are not to exceed 1” in diameter.
Note: The maximum slack storage lengths listed below will be reduced when working with Loose Buer Tube (LBT) cable
containing more than 144 bers.
Note: When using single height tray to store ribbon splices, the ribbons must be routed to the slack basket rst. Do not route
ribbons directly to the tray unless they will be de-ribbonized for single splicing. See the accessory list on page 2 for double
height tray ordering info.
Locking tab
Feet
Post
Handle
Figure 1
Figure 2

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© 2023 CommScope, Inc. All Rights Reserved
7.1 Cable cut lengths
Cable type Opening
location
FOSC450 C closure
Min. & Max. suggested
storage length ***
FOSC450 D closure
Min. & Max. suggested
storage length ***
Strength member cut lengths
Small bracket Large bracket
• Stranded ber Loose
Buer Tube
• Rollable Ribbon
Mid span 52” - 90” in standard basket*
52” - 112” in tall basket
102” - 120” in standard basket*
102” - 140” in tall basket
2” 2.5”
End 43” - 72” 55” - 75” 2” 2.5”
Flat Ribbon cable with single
height tray
Mid span** 80” - 92” 90” - 140” 2” 2.5”
End 30” - 45” 70” - 90” 2” 2.5”
Ribbon cable with double
height tray
Mid span** 80” - 132” 110” - 192” 2” 2.5”
End 45” - 66” 60” - 96” 2” 2.5”
* LBT: 52”/102” goes directly to tray. 90”/120” mid-span cut in center makes one small loop in basket and approx. 22”/36” on tray.
** Ribbon: 80”/90” small loop in basket in front of tower and onto the tray. 92”/140” loop to the end of the basket and onto the tray.
*** The Minimum cut length is based on cutting dead-to-the-eld side going directly to the tray. The Maximum cut length is based on entry into the
basket to tray.
7.2 Loose Buer Tube cable
For loose buer tube cable midspan applications, remove cable sheath for a length identied in the table above. Store any
uncut buer tubes in the slack basket.
7.3 Ribbon cable
For ribbon cable midspan applications, remove cable sheath for a length identied in the table above. To splice the ribbons,
remove all but 9” of tube(s) and attach to the inside of the slack basket. Route the ribbons through the slack basket and up to
the splice trays using braided sleeving or transportation tubes.
8 Cable installation
8.1 Determine which strength member bracket to use. The large strength member bracket is used for cables with
central strength member over ¼” in diameter. However, the large strength member bracket shouldn’t be used at the upper
two ports of the star bracket. Large strength member lugs can only be used with large strength member bracket (Figure 3).
8.2 Cut the cable strength member leaving 2” when using small strength member bracket or 2.5” when using large
strength member bracket.
Small strength
member lug
Large strength
member lug
Large strength
member bracket
Small strength
member bracket
Cable
attachlent
Figure 3
Figure 4

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© 2023 CommScope, Inc. All Rights Reserved
8.3 For armored cable, use company approved bonding hardware for bonding and grounding. If using an alligator-
type bond clip, remove all but 1” of the metal shield. Pry open a 1” tab in the exposed metal shield where the shield overlaps.
See Figure 4. Crimp the bond clip onto the edge of the shield. See Figure 5. Wrap the installed bond wire tightly with two or
three wraps of vinyl tape.
8.4 If using shield bond connector, push the lower plate of the bond clamp under the inner shield so that the stud bolt
is positioned between strength members. Place the upper plate of the B-Bond clamp over cable jacket. See Figure 6.
8.5 Insert strength member(s) into the strength member lug and tighten screw using ¼” nut driver. For central strength
members, use the center prong (Figure 7). For dual strength members, bend the inner prong out of the way and use the two
outer prongs (Figure 8).
8.6 For armored cables place strength member bracket on top of the bonding clamp. Install nut on bond clamp stud
and tighten it (Figure 9 and Figure 10).
Figure 5 Figure 6
Figure 7 Figure 8
Figure 9 Figure 10

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© 2023 CommScope, Inc. All Rights Reserved
8.7 Place cable assembly into cable attachment bracket as shown on Figure 11 and Figure 12.
8.8 Install hose clamp and tighten such that the teeth are fully seated into the cable assembly. Don’t overtighten the
clamp to the point that it deforms. Use 1/4” nut driver to tighten the hose clamp. Figure 13 illustrates cable attachment with
bond shield connector . Figure 14 illustrates cable attachment with alligator clip bond.
8.9 Slide cable attachment bracket and cable into the appropriate slot on star bracket until it locks in place.
Note: Use bottom entry ports for main cables.
Figure 11 Figure 12
Figure 13 Figure 14
Figure 15
Strength member
attachment bracket

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© 2023 CommScope, Inc. All Rights Reserved
9 Routing bers to the splice tray
9.1 Route subunits to the basket or directly to the tray according to the cut length selected in table in section 7.1.
9.2 When routing subunits from basket to tray, go to opposite side of the basket and route around the backside of the
tray tower (Figure 16).
9.3 Place a mark on the buer or transportation tube one inch past the edge of the tray (Figure 17).
9.4 Cut and remove the loose buer tube (LBT) coating and clean bers with an approved degreaser cleaner.
9.5 Wrap the end of the tubes with loose buer tube (LBT) wrap and attach them to the tray with two tie wraps
(Figure 18).
Tip: It is helpful to arrange ribbons in order or organize ribbons prior to inserting them into the transportation tube (basket
location). This will improve organization on the tray.
9.6 Figure 19 below shows routing of LBT bers on single height splice tray.
Figure 16
Figure 18
Figure 17
Figure 19

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9.7 Figure 20 below shows ribbon bers in single height tray where ribbon slack is stored in the basket.
9.8 Double height trays are used to store at matrix ribbon within the tray. Figures 21 and 22 show double height tray
with splice capacity up to 576 bers.
9.9 Tubing should be used to route bers from basket to trays. For at matrix ribbon and Rollable Ribbon bers,
braided sleeving can be used. Braided sleeving accommodates more ber ribbons, provides ber protection, and takes less
space inside basket and tray. Example of braided sleeving is shown in Figure 23 and Figure 24.
Figure 20
Figure 21 Figure 22
Figure 23 Figure 24

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© 2023 CommScope, Inc. All Rights Reserved
9.10 Ribbon holders are used to organize ribbons within the splice tray and protect the ber under tie wraps.
• Install ribbon holders under braided sleeving.
• For 24-ber ribbons, lay the ribbon bundle in the ribbon holder as shown in Figure 25 A and B, remove all the
spacers.
• For 12-ber ribbons, fold the appropriate number of spacers as shown in Figure 26 A, remove the one(s) that will
not be used. All bers should be on one side of the spacers.
• Use the chart in Figure 25 to determine number of spacers to fold down (remove the ones not used).
• Stand the 12-ber ribbons in the ribbon holder as shown in Figure 26 B.
• Once ribbons are in the ribbon holder, fold the other half over and snap shut (Figure 25 B and Figure 26 C).
• Slide the ribbon holder into the sleeving.
• Both 24- and 12-ber ribbons should be oriented vertically when secured to the splice tray. Orientate the ribbon
holder accordingly.
9.11 Wrap a piece of LBT tape over the sleeving and secure to the splice tray with tie wraps (Figure 27).
B
Ribbons Spacers to fold down
24
12
6 or less
0
2
3
A
Figure 25
B
A
C
Figure 26
Figure 27

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© 2023 CommScope, Inc. All Rights Reserved
10 Gel Block Installation
Note: Cables with diameter larger than 1” (25.4mm) and less than 1.04” (26.4mm) can be used, however gel block has to be
modied. For specic instructions please contact CommScope.
10.1 First, turn the “tail” of the gel block counterclockwise to release gel compression, until it stops to ensure that the
cable openings are in the open position. Squeeze the gel block on either side of the top of the block to open it (Figure 29).
10.2 Position the gel block against the spacer on the star bracket. Position the cables and snap the gel block closed.
Warning: Do not use a braided or stranded ground wire when installing ground wire through a port on the FOSC450
closures. To prevent a leak path, only a bonded solid ground wire with sealing kit is to be used. Refer to the external ground
wire installation manual for more details.
10.3 Important: Insert one port plug in each unused port (Figure 31).
10.4 For armored cables, install braided ground wire and nut on ground stud that corresponds to armored cable
position, see Figure 32 and Figure 33.
Figure 28
Tail Gel block
Figure 29
Figure 30 Figure 31
Figure 32 Figure 33

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© 2023 CommScope, Inc. All Rights Reserved
10.5 Slide the base up and over the gel block. The arrow on the base must be at the top of the closure, see Figure 34.
Note: If gel end piece collects dirt, it should be washed o with water only.
10.6 Inside the base, swing the 4 metal washers into position to secure the base to the star bracket. Then tighten the
bolts securely. Conrm the arrow is on top of the base.
10.7 Connect the base bonding wire to cable bonding hardware. See Figure 35 and Figure 36.
10.8 Using the tail, pull gel block away from the closure to seat the gel block to the end of the base. Turn the tail
clockwise until it dead ends at the physical stop to seal cables and plug, see Figure 37.
Note: If more than three cables are installed, the physical stop may not be reached. Turn the tail until it stops.
Warning Do not use drill to turn gel end piece tail as this will damage gel block.
Figure 34
Figure 35 Figure 36
Figure 37

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© 2023 CommScope, Inc. All Rights Reserved
10.9 Place a large tie wrap or vinyl tape around all the cables just beyond the end of the tail.
10.10 Once the splicing is complete, wrap hook and loop fastener strap around the splice trays and basket.
10.11 If desiccant is to be used (optional – ordered separately) install 150 grams of desiccant on top of the uppermost
splice tray. Secure trays and desiccant in place with a hook and loop fastener strap.
Important: Place all unused cable termination hardware in a bag and keep for future cable installations.
Important: Make sure the O-ring is in the correct position.
10.12 Mount dome onto base, aligning arrow on base with arrow on dome.
10.13 Install clamp around dome/base interface. Position feet of handle in front of the two posts and push down on the
handle to pull the two halves of the clamp together.
10.14 Continue to push handle down until the small pin on the handle snaps into the triangular hole in the clamp.
10.15 A security lock or tie wrap may be inserted through the round holes in the handle and clamp to lock the closure.
Figure 38
Feet
Post
Handle Triangular hole
Triangular hole
Figure 39
Figure 40

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© 2023 CommScope, Inc. All Rights Reserved
11 Flash Test
Flash test the closure to a maximum of 5 psi. Thoroughly soap seals to check for integrity.
Important: After ash testing, bleed all pressure from the closure through the valve.
12 Re-entry
Make sure all air is bled from closure. To remove the dome from the closure, release the clamp handle, hook the handle on
the two posts, and pull back until the clamp releases from the closure. Remove the dome and keep the O-ring, clamp, and
dome clean and dry.
13 Adding cables
13.1 Turn the tail of the gel block counterclockwise to loosen the seal between the gel block and the base.
(See Figure 28)
13.2 Loosen the four metal bolts and turn the washers inside the base to release the star bracket from the base.
(See Figure 2)
13.3 Slide the base back over the cables and out of the way.
13.4 Refer to section “7 Cable preparation” on page 3 through section “9 Routing bers to the splice tray” on page
7 to install a new cable and re-seal the closure.
14 Disclaimer
All trademarks identied by ® are registered trademarks in the US and may be registered in other countries. All third party
product names, trademarks and registered trademarks are property of their respective owners.
This product may be covered by one or more U.S. patents or their foreign equivalents. For patents, see www.cs-pat.com.
This document is not intended to modify or supplement any specications or warranties relating to CommScope products or
services.
15 Contact information
Visit our website or contact your local CommScope® representative for more information. www.commscope.com.
For technical assistance, customer service, or to report any missing/damaged parts, visit us at: http://www.commscope.com/
SupportCenter.