3M 7685-S-8 User Manual
3M
™
Cold Shrink QT-III Silicone
Rubber Skirted Termination Kit
With High-K Stress Relief
For Tape Shielded, Wire Shielded and UniShield® Cable
7685-S-8
Instructions
IEEE Std. No. 48
Class 1 Termination
35 kV Class
200 kV BIL
F CAUTION
Working around energized systems may cause serious injury or death. Installation should
be performed by personnel familiar with good safety practice in handling electrical
equipment. De-energize and ground all electrical systems before installing product.
January 2013
78-8119-6018-2 Rev C 3
1.0 Kit Contents
3 High-K, Tracking Resistant, Silicone Rubber Terminations
3 Pre-formed Ground Braids
3 Constant Force Springs
3 3M™ EMI Copper Foil Shielding Tape 1181 Strips, 1/2" x 10"
6 Strips Scotch® Mastic Strip 2230 (black with white release liners, bagged)
1 3M™ Cable Cleaning Preparation Kit CC-2
1 Instruction Sheet
NOTE: Do Not use knives to open plastic bags.
Kit Selection Table
NOTE: Final Determination Factor is cable insulation diameter.
Kit Number
7685-S-8
Primary Insulation
O.D. Range
1.05" - 1.80"
(26,7 - 45,7 mm)
Jacket O.D. Range
1.39" - 2.40"
(35,3 - 61,0 mm)
Table 1
Conductor Size Range (AWG & kcmil)
15 kV 25/28 kV 35 kV
500 - 1000 kcmil
(240 - 500 mm2)
250 - 800 kcmil
(125 - 400 mm2)
3/0-600 AWG
(95 - 325 mm2)
2 78-8119-6018-2 Rev C
Instructions For Tape Shielded Cable
2.0 Prepare Cable
2.1 Check to be sure cable size fits within kit size range as shown in Table 1.
2.2 Prepare cable using dimensions shown in Figure 1. Refer to Table 2 for semi-con cutback dimension.
BE SURE TO ALLOW FOR DEPTH OF TERMINAL LUG. If necessary to prevent tape shield from
unrolling, hold down edge with a single wrap of 3M™ EMI Copper Foil Shielding Tape 1181.
NOTE: Provide additional exposed conductor distance to account for growth during crimping of ALUMINUM
lugs or connectors as follows:
Aluminum Connector
Growth Allowance
NOTE: It is imperative to remove all remnants of the semi-con layer, even if the semi-con layer comes off as one
layer. There should not be any remaining black areas, or particles, on the cable insulation layer.
Kit Number Insulation 0.D.
1.05" -1.46"
7685-S-8
(26,7 - 37,1 mm)
1.24" - 1.80"
(31,5 - 45,7 mm)
2 - 350
1/4” (6 mm)
15 kV
AWG / kcmil
500-700
(240 - 400 mm2)
750-1000
(400 - 500 mm2)
3” (76 mm)
400 - 650
1/2" (13 mm)
25/28 kV
AWG / kcmil
250-500
(125 - 250 mm2)
600-800
(300 - 400 mm2)
Table 2
Jacket Removal Length
Depth Of Terminal Lug + Growth Allowance
Semi-Con Cutback
35 kV
AWG / kcmil
3/0-350
(95 - 150 mm2)
500-600
(185 - 325 mm2)
750–1000
3/4" (19 mm)
Semi-con
Cutback
13.5"
(342,9 mm)
13.0"
(330,2 mm)
1 1/ 2”
(38 mm)
Semi-Con
Tape Shield
Cable Jacket
Figure 1
78-8119-6018-2 Rev C 3
3.0 Install Ground Braid
3.1 Select a Scotch® Mastic Strip 2230 from kit and remove white release liners. Using light tension, apply a
SINGLE WRAP of mastic around the cable jacket 1/4" (6 mm) from cut edge (Figure 2). Cut off excess.
1/4” (6 mm)
Semi-Con
Tape Shield
1ST Scotch® Mastic Strip 2230
Cable Jacket
Figure 2
3.2 Position pre-formed ground braid with short tail over tape shield directly adjacent to cable jacket cut edge.
PLEASE NOTE: The ground braid needs to make full contact with the metallic shield. Position long tail of
ground braid, extending over cable jacket with solder block over mastic strip (Figure 3). Secure ground braid to
cable jacket 4 l/2" (114 mm) from cable semi-con edge using vinyl tape (Figure 3).
NOTE: Position vinyl tape with care, it also serves as a marker for positioning the termination.
4 1/2 (1
Vinyl Tape Marker
14 mm)
Semi-Con Edge
Tape Shield
Ground Braid
Cable Jacket Edge
Solder Block
1ST Scotch® Mastic Strip 2230
Figure 3
4 78-8119-6018-2 Rev C
3.3 Wrap ground braid around cable tape shield one complete wrap, trim excess to prevent overlap and secure in
place with constant force spring. Wrap spring in same direction as ground braid (Figure 4). Cinch (tighten) the
spring after wrapping the final winding.
3.4 Select second Scotch® Mastic Strip 2230 from kit and remove white release liners. Apply a second SINGLE
WRAP of mastic over solder block on ground braid and previously applied mastic (Figure 4). Cut off excess.
Constant Force Spring
Tape Shield
Ground Braid
1ST Scotch® Mastic Strip 2230
Solder Block
2ND Scotch® Mastic Strip 2230
Trim
Cable
Tape
Shield
Ground Braid Leg
Figure 4
3.5 Wrap two highly stretched half-lapped layers of electrical grade vinyl tape around mastic seal, constant force
spring and exposed tape shield (Figure 5).
NOTE: Take care not to cover exposed semi-con insulation shield. A minimum of 1" (25 mm) must be exposed.
SPECIAL NOTE FOR CLOTH OR PAPER SEMI-CON INSULATION SHIELD
In cables with cloth or paper semi-conductive shields, it is recommended the shield be over wrapped with one halflapped layer of highly stretched semi-conductive rubber tape such as Scotch® Electrical Semi-Conducting Tape 13.
Semi-Con
Tape Shield
Constant Force Spring
Two Half-Lapped Layers of Electrical Grade Vinyl Tape
Scotch® Mastic Strip 2230
ape Marker
Vinyl T
Figure 5
78-8119-6018-2 Rev C 5
4.0 Install Lug or Connector
4.1 Check to insure 3M™ Cold Shrink QT-III Silicone Rubber Termination assembly fits over the selected lug
or connector. If lug or connector (Figure 6) will not fit through the termination core, clean the insulation
(per Step 5.0) and slide termination on cable before installing lug or connector.
DO NOT REMOVE CORE AT THIS TIME.
Clearance
Connector/Lug
Figure 6
NOTE: Refer to pages 19-21 for 3M™ Connector and Lug crimping information.
NOTE: For Aluminum Conductors - Thoroughly wire brush conductor strands to remove aluminum oxide layer.
Immediately insert conductor into lug or connector barrel as far as it will go.
4.2 Position connector or lug and crimp according to manufacturer's directions. Remove excess oxide inhibitor and
sharp crimp flashings following crimping.
5.0 Clean Cable Insulation and Lug or Connector Barrel Using Standard Practice
5.1 Wipe the cable insulation with one of the solvent saturated pads from the 3M™ Cable Cleaning Preparation Kit
CC-2. DO NOT ALLOW SOLVENT TO TOUCH SEMI-CON INSULATION SHIELD!
5.2 If abrasive must be used:
a. Use on insulation only. DO NOT USE ABRASIVE ON SEMI-CON INSULATION SHIELD!
b. Use only aluminum oxide abrasive; grit 120 or finer, included in the 3M™ Cable Cleaning Preparation Kit
CC-2.
c. Be careful not to reduce the cable insulation diameter below that allowed by the kit.
6 78-8119-6018-2 Rev C
6.0 Install Termination
6.1 Slide the termination body onto the cable and remove core. Pull while unwinding, counter-clockwise, starting
with the loose end (Figure 7). Make sure the termination body (not the core) is butted up to the edge of the
vinyl tape marker previously applied (Figure 7).
NOTE: Once the termination body makes contact over the mastic seal area, there is no need to continue
supporting the assembly. DO NOT PUSH OR PULL ON THE TERMINATION ASSEMBLY WHILE UNWINDING
THE CORE.
Counter-Clockwise
Vinyl Tape Marker
The material being removed at this step is mixed polymersNOTE:
waste.and can be recycled with
Figure 7
6.2 Connect ground braid to system ground according to standard practice.
Correct Installation of Termination on Tape Shielded Cable
Vi nyl Tape
Marker
Ridge at End
of High-K Tube
Semi-Con Insulation Shield
Stress Controlling Compound
Ridge at End of Cable
Insulation Shield (Semi-Con)
Cable
Insulation
Conductor
Envioronmental
Seal
High-K Stress
Relief Tube
Top
78-8119-6018-2 Rev C 7
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