Better Buried Closures
Instructions
January 2006
78-8135-4353-1-A
1.0 General
1.1
The 3M™ Better Buried Closures are rigid body splice closures designed for direct burial. When filled
with a reenterable encapsulating compound, the closure can be reentered for splice rework.
2.0 Kit Contents
2.1
The kit contents are shown below:
uble End Cap
e Hose Clamps
Single End Cap
Funnel
883656
Visually inspect all components. If any component is missing or appears damaged, do not install and call 3M
Customer Service at 1-800-426-8688 for a replacement product.
2.2
The following materials are included in each 3M™ Better Buried Closure Kit:
B.B.
B.B.
B.B.
B.B.
B.B.
SB/2SC
SB/SC,DC
SB/2DC
SB/DC,TC
Sleeve Kit
Kit Components
2" - 5"
2" - 5"
6" - 9"
7" - 9"
2" - 9"
(50mm-127mm)
(50mm-127mm)
(152mm-229mm)
(178mm-229mm)
(50mm-229mm)
Closure Body
1
2
1
1
1
1
End Cap, Single (SC)
End Cap, Multiple (DC) (TC)
Spacer Web (SW)
Strain Relief Bar (SB)
Hose Clamps, Closure
Hose Clamps, Strain Bar
Funnel
1
1
2
1
2
3
2
1
2
4
1
2
1
2
3
2
1
2
5
1
1
1
1
3
1 or 2
1 or 2
3
2
1
2
2
1
3
2
1
2
1
2
Snap-In Cap
Locking "H"
3 or 4
1
Foam Strips
3
2.3
Additonal Materials Required (Dependent on Kit Contents):
• Shield Connectors
• Better Buried Sleeve Kits (Closure Extension)
• Hose Clamps
• Encapsulating Compound (permanent or
reenterable)
• Vinyl Tape
• 3M™ Scotchcast™ Spacer Web 4430 (for reentry only) • DR Tape
• Sheath Scuff Material
• Pair Saver
• Scotch® Linerless Rubber Splicing Tape 130C
• Scotch® Vinyl Mastic Tape
• 3M™ Scotchcast Strain Relief Bar Kits 4465 or 4465-L • B Sealing Tape
• Moisture Resistant Splicing Connectors
• Better Buried End Caps (bulk)
• Bonding Braid
3.0 Closure Selection Guide
3.1
Select proper closure using the following tables.
3.2
Maximum Splice Bundle Capacities (Straight Splice)
Connector
2" x 12"
2" x 24"
3"x 24"
4" x 24"
5" x 26"
6 x 26"
7 x 26"
9 x 26"
50 x 305mm
50 x 610mm
76 x 610mm
102 x 610mm
127 x 660mm
152 x 660mm
178 x 660mm
229 x 660mm
3M™ MS2™
Splicing Module
4000-DWP
50 pair
0.5 mm
(24 AWG)
UY Only
100 pair
0.5 mm
(24 AWG)
200 pair
0.5 mm
(24 AWG)
400 pair
0.5 mm
(24 AWG)
600 pair
0.5 mm
(24 AWG)
900 pair
0.5 mm
(24 AWG)
1200 pair
0.5 mm
(24 AWG)
2400 pair
0.4 mm
(24 AWG)
3M™ Scotchlok™
Connectors UR
(w/ 3" pigtails)
25 pair
0.6 mm
(22 AWG)
50 pair
0.6 mm
(22 AWG)
100 pair
0.6 mm
(22 AWG)
200 pair
0.6 mm
(22 AWG)
300 pair
0.6 mm
(22 AWG)
400 pair
0.6 mm
(22 AWG)
600 pair
0.6 mm
(22 AWG)
900 pair
0.6 mm
(22 AWG)
3.3
Closure Dimension Guide
Closure End Cap Port Diameters
Maximum Splice Openings
Approx.
Amount
Single
Entry
(Max.)
Multiple Entry (Max.)
Double Sheath
of Comp.
Required
(Ave. Splice)
Single
Sheath
Closure Size
1
2
3
-
Outer
-
Inner
-
2" x 12"
1.2"
30 mm
1.2"
30 mm
0.7"
18 mm
5"
21 oz.
600 gms
(50 x 305 mm)
127 mm
2" x 24"
1.2"
1.2"
0.7"
-
-
-
-
17"
17"
14"
42 oz.
(50 x 610 mm)
30 mm
30 mm
18 mm
432 mm
432 mm
356 mm
1200 gms
3" x 24"
1.6"
41 mm
1.6"
41 mm
1.0"
25 mm
17"
432 mm
17"
432 mm
14"
356 mm
106 oz.
3000 gms
(76 x 610 mm)
4" x 24"
2.0"
51 mm
2.0"
51 mm
1.5"
38 mm
17"
432 mm
17"
432 mm
14"
356 mm
159 oz.
4500 gms
(102 x 610 mm)
5" x 26"
2.4"
61 mm
2.4"
61 mm
1.8"
46 mm
19"
483 mm
19"
483 mm
16"
406 mm
254 oz.
7200 gms
(127 x 660 mm)
6" x 26"
3.3"
84 mm
2.7"
68 mm
2.0"
50 mm
1.5
40 mm
19"
483 mm
19"
483 mm
16"
406 mm
441 oz.
12500 gms
(152 x 660 mm)
7" x 26"
3.5"
89 mm
3.5"
89 mm
2.2"
56 mm
2.2
56 mm
19"
483 mm
19"
483 mm
16"
406 mm
530 oz.
15000 gms
(178 x 660 mm)
9" x 26"
4.0"
102 mm
4.0"
102 mm
2.5"
64 mm
2.5
64 mm
19"
483 mm
19"
483 mm
16"
406 mm
742 oz.
21000 gms
(229 x 660 mm)
Note: All metric conversions are approximate.
4
4.0 LHS End Cap Installation
5.0 Cable Preparations
4.1
End Cap Installation on Cut Cables
Procedure:
5.1
Position and secure cables according to the
splice opening for the closure size selected.
See closure dimension guide for the maximum
splice openings.
a. Select desired port(s).
b. Cut off cone(s) as close as possible to the
diameter of the cable using the cut guides
on either side of the cone(s). See cable
diameter tape on back cover.
5.2
Scuff 6" (152 mm) of outer sheaths as shown.
Wrap all scuffed areas with vinyl tape.
5.3
Note:
Vinyl tape should be removed from under
Shield Bond Connectors when installed.
5.4
Remove outer sheath for a splice opening no
greater than the maximum splice opening
listed for closure size in closure dimension
guide.
English Designation
Metric Designation
842844
5.5
5.6
Remove shield flush with outer sheath.
c. When not slitting cap, place piece of foam
in each slot on inside of cap.
Clean filled cable for good encapsulant
adhesion and sealing.
5.7
Single Sheath Cables Procedure:
6" (152mm) Scuff
88T
Foam Tape
883656
6" (152mm) Scuffed
and Temporarily
Inside End View
Wrapped
Core Wrapper
3/4" (19 mm)
d. Push cable through port and slide end cap
down cable so not to interfere with cable
preparations or splicing.
Sheath Scuff
883655
DO NOT SLIT END CAP UNLESS
INSTALLING ON EXISTING CABLE.
a. Insert base assemblies of shield connectors
between the core wrapper and the shield
180° apart. Insert base assemblies of shield
connectors between the core wrapper and
the shield 180° apart. Install first nut and
torque to 45 ± 5 in-lbs (5.2 ± 0.6 kg·m).
4.2
End Cap Installation on Straight Through
or Express Cable Procedure:
a. Select desired port(s).
b. Cut off cone(s) as close as possible to the
diameter of the cable using the cut guides
on the cone(s). See cable diameter tape on
back cover.
180°
Single Sheath
c. Slit end cap between raised guide rails.
Slit
883657
Note:
Use only 1 (one) sheath connector on each
cable for the 2" (50 mm) diameter closures.
842845
b. Trim core wrapper, leaving 3/4" (19 mm).
d. Place cap around cable.
c. Install insulation sleeve on strain relief
bar(s). Trim length if necessary to clear
mounting holes.
e. Slide locking "H" Strip into place over the
raised guide rails. Start at the large (body)
end and work towards the small end of the
cone. Cut "H" Strip to length.
d. Install one strain relief bar on Shield Bond
Connectors (to hold splice opening and
provide temporary bond.)
"H" Strip in Place
Note:
Branch cables should be bonded according
to illustrations. If necessary, shield
connector studs may be trimmed to clear
cover halves of smaller diameter closures.
2847
842846
f. Slide end cap down so not to interfere with
cable preparations or splicing.
5
3" – 9" Kits
f. Insert base assemblies of the shield
connectors between the inner sheath
and the shield, 180° apart. Insert base
assemblies of shield connectors between
the core wrapper and the shield 180° apart.
Install first nut and torque to 45 ± 5 in-lbs
(5.2 ± 0.6 kg·m).
Strain Relief Bar
Strain Relief Bar
2" Kit
Bonding Braid
883657
180°
e. Splice conductors per standard procedure.
f. To insure thorough encapsulation of
conductors, do not tightly bind the splice
bundle.
Double Sheath
883658
g. Install second bond bar if required.
Note:
Use only 1 (one) shield connector on each
cable for 2" (51 mm) diameter closures.
h. Remove vinyl tape from scuffed sheaths.
Keep these areas clean during the
following bonding and sealing collar
construction operations.
g. Build inner sheath sealing collars on
exposed inner sheaths. Sealing collars are
one wrap of 3/4" (19 mm) B sealing tape
completely overwrapped with highly
stretched DR tape (white side out).
i. Build outer sheath sealing collars just
beyond ends of strain relief bar(s). Sealing
collars are one wrap of 3/4" (19 mm) B
sealing tape. Completely overwrap with
highly stretched DR tape (white side out.)
h. Cover inner sheath sealing collars with
vinyl tape to protect them from
contamination of grease and dirt.
DR Tape
i. Remove core wrap even with inner sheath.
j. Install insulation sleeve on strain relief
bar(s). Trim to length if necessary to clear
mounting holes.
883657
B Sealing Tape
j. Install hose clamps over ends of strain
relief bar(s).
k. Install one strain relief bar on 3M™
Scotchlok™ Shield Bond Connectors (to hold
splice opening and provide temporary bond).
Note:
Rotate hose clamps so heads will not
obstruct fill ports on body.
k. Overwrap strain relief hose clamps with DR
tape to keep hose clamps tails from flagging.
Note:
Branch cables should be bonded according
to illustrations. If necessary, shield
connector studs may be trimmed to clear
cover halves of smaller diameter closures.
5.8
Double Sheath Cables Procedure:
6" (152mm) Scuff
88T
3" – 9" Kits
6" (152mm)
Scuff
Inner Sheath
1-1/2" (38 mm)
Strain Relief
Bars
2" Kit
883658
Sheath Scuff
a. Remove outer sheath and shield for a
splice opening no greater than the
maximum splice opening listed for
closure size in closure dimension guide.
Inner Sheath Sealing Collar
Bonding Braid
883658
l. Splice conductors per standard procedure.
m.To insure thorough encapsulating
compound penetration, do not tightly bind
the splice bundle.
b. Scuff 6" (152 mm) of outer sheath.
c. Wrap scuffed sheath with vinyl tape.
n. Remove Scotch® Vinyl Tape 88T from
scuffed sheath(s) and inner sheath sealing
collars. Keep these areas clean during
the following bonding and sealing collar
construction operations.
Note:
Vinyl Tape should be removed from under
Shield Bond Connector when installed.
d. Scuff 2" (51 mm) of inner sheath.
e. Remove inner sheath, except for 1-1/2"
(38 mm) at both ends of splice opening.
6
o. Install second bond bar if required.
p. Install hose clamps over ends of strain
relief bars.
Note:
Rotate hose clamps so heads will not
obstruct fill ports on body.
1/2"
13mm
q. Overwrap the strain relief hose clamps
with DR tape to prevent hose clamp tails
from flagging.
883660
6.7
Mix compound according to instructions.
r. Build outer sheath sealing collars just
beyond ends of strain relief bars. Outer
sheath sealing collars are one (1) wrap of
3/4" (19 mm) B sealing tape completely
overwrapped with highly stretched DR
tape (white side out).
Note:
Carefully follow health, safety and
environmental information on product
label or Material Data Sheet for
encapsulating compound being used.
6.8
Position closure in final position to be buried,
then fill closure with compound. Continue
mixing and pouring compound until closure is
completely filled and trapped air is removed.
DR Tape
6.9
Close fill ports with the snap-in caps.
B Sealing Tape
6.10
Check for any compound leaks. If leaks are
observed, tighten hose clamps and retape as
required.
883659
6.11
Closure can be buried immediately.
6.0 Closure Assembly
Note:
Make sure all vinyl tape has been removed
from splice encapsulation area.
7.0 Closure Reentry
6.1
Center lower closure half on splice bundle and
attach upper half (upper half has fill ports)
mating the tongue and groove.
7.1
7.2
7.3
7.4
7.5
7.6
Remove hose clamps from closure and end
caps. Remove any tape from end caps.
With a twisting motion, pull end caps from
closure and slide down cable.
Grasping closure at one end, slowly separate
halves from encapsulant.
883659
Remove spacer web from splice and discard.
DO NOT REUSE THIS SPACER WEB.
6.2
6.3
Place one large hose clamp around center of
closure and tighten.
Tear cured encapsulant away, as necessary, to
access splice.
Set end caps in grooves on closure body ends
and secure with large hose clamps. Seal end
caps to cable sheaths with 2 half-lapped layers
of vinyl tape. Start the half-lap layers on the
cable and tape up the cone.
After completion of repair, place 3M™
Scotchcast™ Spacer Web 4430 around splice
and reassemble closure as outlined in Section
6.1 - 6.3. End caps and sleeves can be
reused.
Note:
If original end caps are reused, place a
small piece of B-sealing tape in slots on
inside of caps.
883659
6.4
6.5
Position closure for burial on firmly packed
earth. Avoid sharp bends or kinks in the cable.
Note:
Be sure that the spacer web 4430 does not
block the fill ports.
Slightly incline one closure end about 1/2"
(13 mm). Properly place supports under the
closure for compound filling.
7.7
Fill closure with new compound as outlined in
Sections 6.4 - 6.11.
6.6
Insert funnel into lower closure fill port.
(During filling, air will escape from higher
end.)
7
9.2
Force service wire through port.
8.0 Closure Extension
8.1
Cut a closure body in half using a cable saw
or similar tool. Cut grooves are provided on
closure bodies.
8.2
Assemble the closure by staggering the cut
sections. Position hose clamps. Tape seams
with LR tape or vinyl tape.
883661
Half Body Top
Full Body Top
9.3
Scuff service wire sheath that will be located
inside closure. Build a sealing collar on
each service wire. Service wire collars are
one wrap of 3/4" B sealing tape completely
overwrapped with highly stretched DR tape
(white side out). Align the service wire
sealing collars directly over the outer sheath
sealing collars on main cable.
75350
Full Body Bottom
Half Body Bottom
8.3
Fill closure with compound as outlined in
Sections 6.4 - 6.11.
DR Tape
9.0 Adding Service Wires (2" - 5",
50mm - 125mm Closures)
Service Wire
Sealing Collar
9.1
Cut a small "+" pattern through the service
wire port.
812027
9.4
9.5
Bond per standard procedure.
Install end cap. (See Section 4). Tighten hose
clamps.
9.6
Complete closure assembly per Sections 5
and 6.
883661
3M, Scotchcast, Scotchlok and MS2 are trademarks of 3M Company.
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accuracy or completeness is not guaranteed. Before using this product, you must evaluate it and determine if it is suitable for your intended
application. You assume all risks and liability associated with such use. Any statements related to the product which are not contained in
3M’s current publications, or any contrary statements contained on your purchase order shall have no force or effect unless expressly agreed
upon, in writing, by an authorized officer of 3M.
Warranty; Limited Remedy; Limited Liability.
This product will be free from defects in material and manufacture for a period of one (1) year from the time of purchase. 3M MAKES NO
OTHER WARRANTIES INCLUDING, BUT NOT LIMITED TO, ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR
A PARTICULAR PURPOSE. If this product is defective within the warranty period stated above, your exclusive remedy shall be, at 3M’s
option, to replace or repair the 3M product or refund the purchase price of the 3M product. Except where prohibited by law, 3M will not
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theory asserted.
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© 3M 2006 78-8135-4353-1-A
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