FAQs: Medium and High Voltage Cable Accessories (5kV – 145kV)

Terminations • Splices • Motor Leads

Answers to frequent questions about medium and high voltage cable accessories from 3M

In addition to answers, you’ll find: instruction videos, tech data sheets, direct product URLs, and brochures. Clicking any of these links will jump you to that particular category.

Medium Voltage Terminations, 5kV - 46kV
Medium Voltage Splices, 5kV - 46kV
Medium Voltage Motor Lead Kits, 5kV - 8kV
High Voltage Terminations, 69kV - 145kV
High Voltage Splices, 69kV - 145kV

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Medium voltage terminations, 5kV - 46kV

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What is the difference between 3M™ Cold Shrink QT-III and QT-II Silicone Rubber Termination Kits?
- 3M™ Cold Shrink QT-II and QT-III Terminations function in a similar manner. They both employ 3M cold shrink technology which utilizes a high-dielectric constant (Hi-K) stress control tube. The Cold Shrink QT-II employs a dielectric grade silicone grease in conjunction with the stress control tube while the Cold Shrink QT-III employs a conformable Hi-K stress controlling compound. The termination is made from a pre-stretched Hi-K stress control tube and a silicone rubber termination insulator body installed around a core. When the core is removed, the rubber provides a constant inward pressure on the cable, forming a seal which expands and contracts with variations in temperature and load, thereby creating a ‘living seal.’
  
  The silicone rubber material used to make the Cold Shrink QT-III termination has better track-resistant properties than the Cold Shrink QT-II, while allowing for a much shorter design without sacrificing product performance. This is especially important when space is in an issue as in cabinet placements. In addition, there are fewer steps involved when using a Cold Shrink QT-III termination so installation is simpler and generally quicker than the QT-ll termination.
  
  Discover more about 3M Terminations for Electrical Construction and Maintenance.
  
  Download brochures:
  3M™ Cold Shrink QT-III Indoor and Outdoor Terminations (PDF, 1.17 MB)
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How do I assemble a 3M™ Cold Shrink QT-III Termination Kit?
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- Assembling a Cold Shrink QT-III Silicone Rubber Skirted Termination Kit for Tape Shielded Cables.
  
  Aside from cable prep, 3M™ Cold Shrink QT-III Terminations have only two primary installation steps, making it easier to assemble than the 3M™ Cold Shrink QT-II Termination.
  
  Apply the mastic seal at the bottom (around the neutrals for JCN* or around the ground strap for tape shielded cable).
  
  Install the termination body.
  
  Both the stress control material and the top seal material are incorporated into the design of the termination body in the Cold Shrink QT-III termination.
  
  Download brochure:
  3M™ Cold Shrink QT-III Indoor and Outdoor Terminations (PDF, 1.2 MB)
  
  * Jacketed Concentric Neutral cable
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How do I assemble a 3M™ Cold Shrink QT-II Termination Kit?
Aside from cable prep, 3M™ Cold Shrink QT-ll Terminations has 4 primary installation steps (whereas the 3M™ Cold Shrink QT-III Termination has only 2).
1. Apply the mastic seal at the bottom (around the neutrals for JCN* or around the ground strap for tape shielded cable).
2. Apply the silicone lubrication at the semi-con step.
3. Install the termination body.
4. Apply Scotch® Self Fusing Silicone Rubber Electrical Tape 70 at the top of the insulator.
Download an instruction sheet:
3M™ Cold Shrink QT-II Silicone Rubber Termination Kits for Shielded Cables (PDF, 176 KB)

* Jacketed Concentric Neutral cable
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Can I use an indoor (non-skirted) termination outdoors?
- No, unless the following conditions are met:
  They are qualified as IEEE-48 Class 1 for indoor and weather-protected applications. For outdoor applications use one-piece, skirted silicone rubber terminations which meet IEEE-48 Class 1 for outdoor weather-exposed applications. Indoor terminations, such as the 3M™ Cold Shrink QT-III Silicone Rubber Indoor Tubular Termination Kits, 7640-T and 7650-T Series, can be specified for most outdoor, pad-mounted switchgear and transformer applications, since these enclosure interiors are protected from direct exposure to the elements.
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If I have 3M™ Cold Shrink single conductor (1/C) termination kits, can I use them for three-conductor (3/C) applications?
- Yes. The 3M™ Cold Shrink Three Conductor Breakout Kit (3C-BOK Series) can be combined with your 3M™ Cold Shrink Single Conductor Accessories for 3 conductor applications. There are six 3C-BOK Kits in the series. Select the one that accommodates your cable dimensions, such as the cable insulation outer diameter (O.D.) (sometimes referred to as diameter over insulation) cable O.D., conductor size and insulation level (i.e., 100% or 133%).
  
  3M™ Cold Shrink Three Conductor Breakout Kit 3C-BOK Brochure (PDF, 881.3 KB)
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What IEEE Standard 48 Class do 3M™ Terminations meet?

All 3M™ Cold Shrink skirted terminations meet the IEEE-48 Class 1 for outdoor weather-exposed applications. All 3M Non-skirted Terminations are qualified as IEEE-48 Class 1 for indoor and weather-protected applications, except for two terminations, which are classified as Class 3. These IEEE-48 Class 3 terminations are: 3M™ Cold Shrink QT-II Silicone Rubber Termination Kit 5671 and 3M™ Cold Shrink QT-II Silicone Rubber Termination Kit 5672 for CN and JCN cables.*

*Concentric Neutral and Jacketed Concentric Neutral

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What's the difference between one-conductor (1/C) JCN* termination kits and one-conductor (1/C) Tape Shield termination kits?

The difference is the kit contents. JCN kits include a single termination, mastic sealing strips for bottom seal and Instructions. Tape Shield kits include three terminations, mastic sealing strips for bottom seal, Instructions, ground braids, constant force springs, copper tape strips and cable cleaning pads.

*Jacketed Concentric Neutral

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What is an inverted, skirted termination kit?
- An inverted, skirted termination kit includes a non-skirted termination on one core and skirts on another core. The non-skirted termination is installed first and then the skirt assembly is installed on top of the non-skirted termination so that the skirts are oriented in the proper downward direction when the termination and cable are installed from the top direction versus the bottom direction, such as in a cabinet.
  
  See a product example:
  3M™ Cold Shrink QT-III Outdoor 4 Skirt Termination 7693-2-INV-4
  
  Download a brochure:
  3M™ Cold Shrink QT-III Indoor and Outdoor Terminations (PDF, 1.17 MB)
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Can the skirts in a 3M™ Cold Shrink QT-III Inverted Termination Kit be installed in the non-inverted (conventional) orientation?

Yes, the skirted insulator assembly can be installed in an inverted or non-inverted (conventional) orientation. The procedure is in the instructions that will be included with the inverted, skirted termination kit.

Instructions for Inverted Termination Kits:

3M™ Cold Shrink QT-III Silicone Rubber Inverted Termination Kits for JCN and CN cable (PDF, 1.59 MB)

3M™ Cold Shrink QT-III Silicone Rubber Inverted Termination Kits for Tape Shield, Wire Shield and UniShield® Cable (PDF, 2.04 MB)

Download a brochure:
3M™ Cold Shrink QT-III Indoor and Outdoor Terminations (PDF, 1.17 MB)

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Does 3M have medium voltage (5kV-46kV) heat shrink terminations?

No, we offer silicone cold shrink terminations for medium voltage. 3M cold shrink technology utilizes a high-dielectric constant (Hi-K) stress control tube and conformable Hi-K stress controlling compound. The pre-stretched rubber is wrapped around a core. When the core is removed, the rubber provides a constant inward pressure on the cable, forming a seal which expands and contracts with variations in temperature and load, forming a ‘living seal’. We do offer heat shrink products for low voltage (<1 kV) applications.

Would you like to learn more about how cold shrink technology can help decrease installation time and provide better environmental sealing? Check out the Cold Shrink Revolution.

Download the catalog:
3M Medium Voltage Termination Kit Catalog(PDF, 4.70 MB)

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Medium voltage splices, 5kV - 46kV

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Does 3M have medium voltage (5kV-46kV) heat shrink splices?

No, we offer silicone cold shrink or EPDM* rubber splices for medium voltage.

3M cold shrink technology utilizes geometric stress control. The pre-stretched rubber splice is wrapped around a core. When the core is removed, the rubber provides a constant inward pressure on the cable, forming a seal which expands and contracts with variations in temperature and load, forming a ‘living seal’. We do offer heat shrink products for low voltage (<1 kV) applications.

Would you like to learn more about how cold shrink technology can help decrease installation time and provide better environmental sealing? Check out the Cold Shrink Revolution.

Download the catalog:
3M™ Low and Medium Voltage Splice Kit catalog (PDF, 12.3 MB)

*ethylene propylene diene monomer rubber

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Does 3M have a 5kV splice for transitioning from non-shielded cable to shielded cable?
- Yes, the 3M™ Cold Shrink Splice Kit 5550 Series Splice Kits are made to join non-shielded to shielded cable. These medium voltage splices allow you to splice 5/8 kV-rated power cables with aluminum or copper conductors. This kit is designed to splice tape shield, wire shield, UniShield® or non-shielded cables.
  
  Our splice kits use EPDM* rubber which is designed to meet the continuous-current rating of the cable that the splice accommodates.
  
  See the products:
  3M™ Cold Shrink Rubber Splice Kit 5551, Tape, Wire, Unishield® 5/8kV
  
  3M™ Cold Shrink Rubber Splice Kit 5552, Tape, Wire, Unishield® 5/8kV 4/0
  
  Download the catalog:
  3M™ Low and Medium Voltage Splice Kit catalog (PDF, 12.3 MB)
  
  *ethylene propylene diene monomer rubber
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What is the difference between your 3M™ Cold Shrink QS-III and QS4 Splice Kits?
- A. 3M™ Cold Shrink QS4 Integrated Splice B. 3M™ Cold Shrink QS-III Splice
  
  Both splice families use the same molded silicone rubber splice body. The 3M™ Cold Shrink QS-III Splice Kit has two cores and the 3M™ Cold Shrink QS4 Splice Kit has a single core. The QS4 splice is integrated, making fewer steps and thereby reducing installation time. In the QS4 splice kits, all of the additional components are directly loaded on the splice body, including the shield sock and re-jacketing tube.
  
  The Cold Shrink QS4 Splice features an Easy-Pulling Installation Core: The easier-unwinding, smooth edged yellow core provides for an installation of the splice with less effort. The Cold Shrink QS4 Splice’s integrated rejacketing eliminates the additional core that is used in Cold Shrink QS-III splice.
  
  Download a brochures:
  3M™ Cold Shrink QS4 Integrated Splice Kit (PDF, 845.5 KB)
  
  3M™ Cold Shrink QS-III Splice Kit (PDF, 462.5 KB)
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Medium voltage motor lead kits, 5kV - 46kV

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Can I insert more than 2 cables into the motor lead boot?
- Our kits are designed to accommodate one feeder cable and one motor cable. If you have an application in which more than two cables are being connected, you will need to measure the approximate outside diameter (O.D.) of the cables you are using in your application and compare that to the inside diameter (I.D.) of the boot for the kit you are intending to use. Visit our product catalog for more information on 3M™ Motor Lead Connections and Kits.
  
  Download catalog:
  Motor Lead Connections (PDF, 1.3 MB).

High voltage terminations, 69kV - 145 kV

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Does 3M make a replacement for a failing porcelain oil filled 69 kV termination?
- Yes, the 3M™ Cold Shrink QT III Cold Shrink Termination kit, a non-self-supporting termination which meets or exceeds IEEE-48 Class 1 standard for 69kV, and IEC 60840 for 72.5kV terminations for outdoor applications.
  
  This kit is lightweight and safer to use as no flame or torch is needed and cold shrink technology eliminates the need for oil filled terminations.
  
  View more information about:
  High Voltage splices and terminations for power transmission
  
  Download brochure:
  High Voltage Underground Cable Accessories for 69 kV/72.5 kV (PDF, 2 MB)
Does 3M have a 69kV termination?
- Yes, we have the 3M™ Cold Shrink QT-III Termination Kit 7673-S-8 Series for 69/72.5 kV (8-skirted). We also have the 3M™ Cold Shrink QT-III Termination Kit 7673-S-10 series which has an additional 2 skirts if your installation is in a heavily polluted area or additional creepage distance is desired.
  
  NOTE: The 7673 Series does not come with lugs, but we have a series of shear bolt options to be included with the kit.
  
  For custom kitting, customers can take advantage of our complimentary 3M Construction Services.
  
  More information:
  3M™ Cold Shrink QT-III Termination Kit 7673 Series
  
  Download brochure:
  High Voltage Underground Cable Accessories for 69 kV/72.5 kV (PDF, 2 MB)
Does 3M have terminations at voltage classes higher than 69kV?

Yes, all terminations above 69kV will be custom kitted. In order to determine proper kit components an application engineer from 3M will have to be contacted. You will need a detailed cable data sheet so we can make sure that all of our accessories will fit your application.

For custom kitting, customers can take advantage of our complimentary 3M Construction Services.

More information:
High voltage terminations for power transmission

High Voltage Splices, 69kV - 145kV

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Does 3M have a 69kV splice?
< Previous Next >
- Watch an installation video: 3M™ Cold Shrink QS-III Splice Kit at 69kV.
  
  Yes, at 69kV we have the 3M™ Cold Shrink QS-III Joint Kit 5488A Series for 69 kV. The kit features a cold shrink design for quick and easy installation, ideal for cable size transitions. These splices come kitted with connectors, while our medium voltage splices can be connector independent. The specific kit chosen will be based on the cable conductor size.
  
  The Cold Shrink QS-III Joint Kit provides a high-quality joint for joining these shielded cables:
  
  Jacketed concentric neutral (JCN)
  
  Tape shield (TS)
  
  Longitudinally corrugated (LC) shielded
  
  Tape-over-wire (TOW)
  
  Wire-over-tape (WOT)
  
  Download brochure:
  High Voltage Underground Cable Accessories 69kV/72.5 kV (PDF, 637.3 KB)
  
  Find out more:
  High Voltage Splices and Terminations for Power Transmission
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Does 3M have splices at voltage classes higher than 69kV?

Yes, we have splices and terminations through 138kV. All splices above 69kV will be custom kitted. You’ll need to contact an application engineer from 3M. We will determine the proper kit components based on the details you provide about your cable which can be found on your cable data sheet.

More information about high voltage products can be found at 3M.com/highvoltage.

For custom kitting, customers can take advantage of our complimentary 3M Construction Services.

Download brochure:
High Voltage Underground Cable Accessories 69 kV/72.5 kV (PDF, 637.3 KB)

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