3M 7620-T-95 User Manual

1.18 Mb

3MCold Shrink QT-III Silicone

Rubber Indoor Termination Kit

With High-K Stress Relief

For Tape Shielded, Wire Shielded and UniShield® Cable



IEEE Std. No. 48

Class 1 Termination 5/8 kV Class

95 kV BIL


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.

March 2013


78-8113-5098-8 Rev F

1.0 Kit Contents

3 High–K, Tracking Resistant, Silicone Rubber Terminations

3 Preformed Ground Braids

3 Constant Force Springs

3 3MEMI Copper Foil Shielding Tape 1181 Strips, 1/2" x 10"

6 Strips Scotch® Mastic Strip 2230 (black with white release liners, bagged) 1 3MCable 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.




Conductor Size Range (AWG & kcmil)

Kit Number

Primary Insulation

Jacket O.D. Range

5 kV

8 kV

O.D. Range











0.32"– 0.59"

0.52" – 0.78"

8 – 4

8 – 6

(8,1 – 15,0 mm)

(13,2 – 19,8 mm)






Table 1




78-8113-5098-8 Rev F

Instructions For Tape Shielded Cable

2.0Prepare Cable

2.1Check to be sure cable size fits within kit range as shown in Table 1.

2.2Prepare cable using dimensions shown in Figure 1. 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 3MEMI Copper Foil Shielding Tape 1181.

NOTE: Provide additional 1/4" (6 mm) exposed conductor distance to account for growth during crimping of ALUMINUM lugs or connectors.

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.

2.3Select a Scotch® Mastic Sealing 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 1). Cut off excess.


Jacket Removal Length


Depth Of Terminal Lug + Growth Allowance


6 3/4" (171 mm)


2" (51 mm)

1/4" (6 mm)

1" (25 mm)




Tape Shield

Cable Jacket

1ST Scotch® Mastic Strip 2230


Figure 1

78-8113-5098-8 Rev F


3.0Install Ground Braid

3.1Position 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 tape shield. Position long tail of ground braid, extending over cable jacket with solder block over Scotch® Mastic Sealing Strip 2230 (Figure 2). Secure ground braid to cable jacket 3 1/2" (89 mm) from cable semi-con edge using vinyl tape (Figure 2).

NOTE: Position vinyl tape with care, it also serves as a marker for positioning the termination.

3 1/2" (89 mm)

Semi-Con Edge

Tape Shield

Ground Braid

Cable Jacket Edge

Solder Block

1ST Scotch® Mastic Sealing Strip 2230

Vinyl Tape Marker

Figure 2

3.2Wrap 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 3). Cinch (tighten) the spring after wrapping the final winding.

3.3Select second Scotch® Mastic Sealing 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 3). Cut off excess.


Constant Force Spring



Tape Shield




Ground Braid



Scotch® Mastic Sealing Strip 2230




Solder Block



Scotch® Mastic Sealing Strip 2230





Ground Braid Leg

Figure 3


78-8113-5098-8 Rev F

3.4Wrap two highly stretched half-lapped layers of electrical grade vinyl tape around Scotch® Mastic Strip 2230, constant force spring and exposed tape shield (Figure 4).

NOTE: Take care not to cover exposed semi-con insulation shield. A minimum of 3/4" (19 mm) must be exposed.


In cables with cloth or paper semi-conductive shields it is recommended the shield be over wrapped with one half-lapped layer of highly stretched semi-conductive rubber tape such as Scotch® Electrical Semi-Conducting Tape 13.


Tape Shield

Constant Force Spring

Two Half-Lapped Layers of Electrical Grade Vinyl Tape

Scotch® Mastic Sealing Strip 2230

Vinyl Tape Marker

Figure 4

4.0Install Lug or Connector

4.1Check to insure 3MSilicone Rubber Termination QT–III termination assembly fits over the selected lug

or connector. If lug or connector (Figure 5) 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




Figure 5

NOTE: Refer to pages 17-19 for 3MConnector 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.

4.2Position connector or lug and crimp according to manufacturer's directions. Remove excess oxide inhibitor and sharp crimp flashings following crimping.

5.0Clean Cable Insulation and Lug or Connector Barrel Using Standard Practice

5.1Wipe the cable insulation with one of the solvent saturated pads from the 3MCable Cleaning Preparation Kit

CC–2. Do not allow solvent to touch semi-con insulation shield!

5.2If 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 3MCable Cleaning Preparation Kit CC-2.

c.Be careful not to reduce the cable insulation diameter below that allowed by the kit.

78-8113-5098-8 Rev F


6.0Install Termination

6.1Slide the termination body onto the cable and remove core. Pull while unwinding, counter-clockwise, starting

with the loose end (Figure 6). Make sure the termination body (not the core) is butted up to the edge of the vinyl tape marker previously applied (Figure 6).

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.


Vinyl Tape Marker


NOTE: The material being removed at this step is mixed polymers

and can be recycled with


Figure 6

6.2Connect ground braid to system ground according to standard practice.

Correct Installation of Termination on Tape Shielded Cable

Vinyl Tape




Ridge at End of Cable




Ridge at End of Stress

Insulation Shield (Semi-Con)




Controlling Compound



Semi-Con Insulation Shield


Environmental Top

Stress Controlling Compound





Cable Insulation






78-8113-5098-8 Rev F

+ 14 hidden pages