3M Cable Joints & Terminations

The 5 Factors To Assessing Cable Splice Life Expectancy

Cable Splicing

Assessing Life Expectancy

Guest Article | 3M Electrical Canada

Thorne & Derrick Stockists & Distributors for 3M Electrical Since 1985

Scotchcast, Scotch & ColdShrink Joints, Terminations up to 66kV Ex Stock

Cable splice failures are expensive, so just imagine the dire consequences of a power failure leaving over 700,000 customers without power. Many of us in Ontario can still recall the shock of the 2003 Northeast Blackout.

As a consumer of electricity our expectation is that our lights stay on, our fridges stay cold, and our roads stay safe with operating traffic lights. When the lights go out, utilities have the extensive task of finding the source of the electrical or power cable fault, communicating with public and customers, and taking on the cost of repair including labour costs.

How do utilities actively try to prevent electrical failures?

Utilities measure system average interruption duration index (SAIDI) and customer average interruption duration index (CAIFI) as both of these are negatively impacted by underground cable splices and their failures. They are constantly looking for ways to help improve these measurements – and improvement comes down to choosing safe and reliable MV Cable Accessories.

Identifying this need within the utility industry, I created a Whitepaper that evaluates the five critical factors to help determine the overall life expectancy of a cable splice. I did this by leveraging 3M Cold Shrink QS-III’s 23 years of field experience.

➡ Did you know: Some of the 3M Cold Shrink Products installed in the field are still operational after almost 50 years!

The goal of this study is to help provide utilities with research and insights to help improve their SAIDI and CAIFI measurements.

Study highlight: 5 factors to help determine the life expectancy of an electrical Cable splice

1. Technology: Reliability of an electrical cable splice hinges on your ability to maintain radial splice pressure on the cables. 3M™ Cold Shrink QS-III is equipped with 3M™ Cold Shrink Technology, which retains radial pressure over the life of the cable splice. As a result, there is no loss of pressure with heat cycling.
2. Materials: Elasticity and the capability to apply in cold environments (especially in Canada’s frigid winters) are critical. 3M™ Cold Shrink QS-III’s silicone rubber is an excellent material choice for splicing applications. It acts as a “living seal” – helping provide long-term elasticity (including at negative temperatures) and has great electrical properties required by a robust splice design. Additionally, we use silicone rubber filled with thermally conductive additives to help improve heat dissipating properties of the splice body.
3. Design: An electrical cable splice or cable joint must be designed to manage electrical stresses by minimizing them for increased long-term performance. 3M™ Cold Shrink QS-III’s moulded splice body exhibits design features that lower electrical stresses. The features include large electrical geometric stress cones, rounded semi-conductive electrodes with an undercut insulation that lower stresses at cable/splice interface and additional insulation thickness at the end of the inner electrode to compensate for increased stresses in this area.
4. Workmanship: Workmanship in splice installation and cable preparation have a great impact in long-term performance. A clear majority of cable failure investigations that I’ve run for our customers pinpoint poor workmanship in cable preparation techniques as the leading root cause for failures. Some of the negative impacts of inconsistent cable preparation and/or cable cleaning that increase electrical stresses can be mitigated by design features such as the rounded semi-conductive electrode with an undercut of insulation that lowers stresses in the area of the splice/cable interface.  3M™ Cold Shrink QS-III is designed to help mitigate these cable preparation errors and the moulded electrical splice body offers ease of installation and high quality.
5. Testing Procedures: A product that is designed and tested at levels meeting and exceeding industry standards will have an adequate long-term performance. For 3M™ Cold Shrink QS-III qualification testing, we rate our electrical splices one basic insulation level (BIL) level higher than the corresponding splice classification (ex. 15kV splices meet the BIL requirements of a 25kV splice).

Further Reading

• Cable Terminations | Cold Shrink Terminations MV HV Cables
• 3M Cold Shrink Terminations Connecting Nexans 12kV (MV) Cable Onto Busbar
• 66kV Terminations | NEW Stock Introduction for 3M Cold Shrink Cable Terminations
• 3M Terminations | Surface Tracking on Medium Voltage Cable Terminations by 3M

THORNE & DERRICK

T&D are Specialist Distributors to UK Distribution Network Operators (DNO’s), NERS Registered Service Providers, ICP’s and HV Jointing Contractors of an extensive range of LV, MV & HV Jointing, Earthing, Substation & Electrical Equipment – this includes 11kV/33kV/66kV joints, terminations and connectors for both DNO and private network applications.

Contact our UK Power Team for competitive quotations, fast delivery from stock and technical support or training on all LV-HV products.

Key Product Categories: Duct Seals | Cable Cleats | Cable Glands | Electrical Safety | Arc Flash Protection | Cable Jointing Tools | Cable Pulling | Earthing | Feeder Pillars | Cable Joints LV | Joints & Terminations MV HV 

3M Medium Voltage EPDM Separable Connectors Plug In Selection Guide

3M Medium Voltage EPDM Separable Connectors Plug In Selection Guide

Medium Voltage EPDM Separable Connectors

The easy to install range of plug-in separable connectors from 3M are moulded using high quality EPDM and meet the requirements of EN 50180 and EN 50181.

Designed for indoor use and suitable for a wide range of applications the straight, elbow and T-Plug connectors are sold in packs of 3 and come with silicone stress control elements, earthing set, mechanical cable lug for main conductor, mechanical cable lug for wire screen, all assembly materials and assembly instructions.

All medium voltage connector kits are fully type tested to Cenelec HD 629.1 (DIN VDE 0278) and are available for voltage classes 6.6/11(12)kV, 20/22(24)kV, and 19/33(36)kV.

The screened separable connectors are suitable for single core, copper wire screened, un-armoured cables, in a wide range of sizes, for outer cone bushings.

Individual range data sheets are available, with full details of each kit – please contact Thorne & Derrick for more information.

3M Medium Voltage EPDM Separable Connectors

3M HV Inner Cone Plug In Separable Connectors

Technical Specification 6.6/11 (12) kV Cables

3M HV Inner Cone Plug In Separable Connectors are designed for inner cone bushings up to 11/12kV voltages and single core polymeric power cable systems with copper wire screen cables according to EN 50180/50181 for Interface types 1, 2 and 3 when connection to metal enclosed switchgear and transformers is required.

Connector Kits include:

• 1. Pressure ring with lamellated contact
• 2. Cone Clamp
• 3. Pressure Disc
• 4. Silicone Rubber Insulator with integrated stress control element
• 5. Pressure spring with support rings
• 6. Entry gland of silumin with fixing flange
• 7. Insulating wrap
• 8. Earth connection (shown for clarity)
• 9. XLPE Cable (shown for clarity)
• 10. Bushing (shown for clarity)

➡ Go to Cold Shrink Terminations to view MV-HV cable terminations for 6.6kV, 11kV, 33kV and 66/132kV cables. Also – cable accessories including high-fault current rated cable glands, cable cleats and cable jointing tools for jointing and terminating of MV/HV power cables.

Cable Box Terminations & Connectors – Inner Cone & Outer Cone

Cold shrink is typically used for the dry termination of medium/high voltage 11kV-33kV cables into MV-HV air insulated cable boxes.

T&D also distribute MV-HV Connectors for terminating cable into metal-enclosed SF6 insulated medium voltage switchgears (GIS) and liquid immersed transformers.

• Nexans Euromold Separable Connectors – elbow-shaped, straight or T-shaped connectors for outer cone bushings
• Pfisterer CONNEX Plugs – medium voltage cable plugs for inner cone bushing sizes 1, 2 or 3

Cold Shrink Technology & Moulded Parts For Electrical Installation | Fast & Easy To Install

3M Cold Shrink

Cold shrink tubing and moulded parts for electrical installation

Invented over 40 years ago by 3M, 3M Cold Shrink Technology is designed to make cable insulating, termination and abandonment as simple as possible. The secret of 3M Cold Shrink technology lies inside it, in the form of a plastic coil. After the 3M Cold Shrink Tube has been placed over the joint or cable end, this inner spiral is pulled out. The insulating tube then contracts and seals onto the cable, exerting constant radial pressure for the lifetime of the joint or termination.

3M Cold Shrink Tubes are installed easily and reliably without the use of cable jointing tools (e.g. gas torches or naked flames). The Cold Shrink tubes manufactured by 3M Electrical are made from extruded EPDM (Ethylene-Propylene-Diene-Monomer) or silicone rubber that are stretched onto a spiral core.

The benefits of cold shrink tubes clear a long-term environmental seal that has high performance even in extreme conditions.  The tool-free installation reduces downtime, installation time and training requirements.

3M Cold Shrink End Caps

Cold Shrink Applications

• Electrical insulation up to 1000 volts
• Insulation of low voltage joints for electrical cables
• Cold Shrink is suitable for indoor and outdoor use
• Mechanical protection of installation
• Cable jacket repair
• Protecting and sealing non-electric applications

Silicone

Cold Shrink Advantages

• Easy and safe installation
• High reliability
• High shrink ratio
• Compressive environmental seal
• Tool-less installation of Cold Shrink
• Reduced contractor training requirement
• Reduced installation time compared to heat shrink
• High performing in extreme conditions

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THORNE & DERRICK are national distributors of LV, MV & HV Cable Installation, Jointing, Duct Sealing, Substation & Electrical Equipment – we service UK and global businesses involved in cable installations, cable jointing, substation earthing, overhead line and electrical construction at LV, 11kV, 33kV and EHV.

Since 1985, T&D have established an international reputation based on SERVICE | INTEGRITY | TRUST.

Contact us for 3M Electrical, ABB, Alroc, AN Wallis, CATU Electrical, Cembre, Centriforce, CMP, CSD, Elastimold, Ellis Patents, Emtelle, Euromold, Filoform , Furse, Lucy Electric & Zodion, Nexans, Pfisterer, Polypipe, Prysmian, Roxtec, Sicame, WT Henley.

3M™ Scotchcast™ Resin 4 GS with Colour Indicator and 92 GS Series Resin Kits

3M 92 GS Series Kits – Mould Body and Connection

3M™ Scotchcast™ Resin 4 GS with Colour Indicator

Professional Cable Jointing Solutions

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The new 3M™ Scotchcast™ Resin 4 GS is a CMR (Carcinogenic, Mutagenic, Reprotoxic) free electrical cable jointing resin has a unique colour mixing indicator to show installers when the resin is correctly mixed by the cable jointer.

Scotchcast™ Resin 4 GS comes in a 2-part transparent bag with integrated pouring spout, ensuring mess-free effortless application. The high-performing formulation means the resin will cure to joint or repair the cable, even in the presence of water.

These 3M Scotchcast resin kits are tested according to EN 50393, CMR-Free substance, compatible with EU Directive 2002/95 / EC (RoHS) and EU regulation 1907/2007/ EC (REACH).

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What is 3M Scotchcast Resin 4 GS?

• A unique electrical jointing resin from 3M
• Newly designed formulation provides colour change indicator for mixing
• Free of CMR substances, Isocyanate, Halogens and SVHC
• Enhanced water and humidity resistance during curing
• Mess free, rapid installation of the cable joints for low voltage cables
• Supplied as bags or as part of the Scotchcast 92 GS Series Resin Kits

Simple, colour indicating mixing

Through a colour change indicator, the 3M Scotchcast resin will turn green when properly mixed by the installer, engineer or cable jointer.

• Newly designed CMR-free formulation
• Unique colour change indicator
• Enhanced water and humidity resistance
• Fully integrated mess-free delivery spout
• Immediate power-up
• Choice of bag sizes to suit your application

*Gel time at 23°C for 92-NBA 3 GS

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3M Scotchcast 92 GS Series

Resin Kits

3M Scotchcast 92 GS Series Resin Joint Kits with Resin 4 GS are easy to install, mess-free applications with 3M professional cable jointing solutions.

Transparent two-chamber bag with an integrated spout ensures no contact with resin during pouring.
Open the seam between the two chambers to mix the resin and hardener.
In approx. 2 minutes the resin will turn green to indicate it is thoroughly mixed.
A visible colour change indicates the mixture is ready to pour.
Place the spout on the mould body, quarter turn to release the resin and fill the kit.
Resin colour changes into darker green as the curing proceeds.

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3M – DISTRIBUTORS, STOCKISTS & SUPPLIERS

Thorne & Derrick provide competitive prices and fast delivery from stock for the complete range of 3M Scotchcast and Cold Shrink cable joints, terminations, resins and Scotch electrical tapes – we stock high voltage cable joints and terminations manufactured from 3M using Cold Shrink for 11kV and 33kV cables.

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LV, MV & HV Jointing, Earthing, Substation & Electrical Eqpt

Thorne & Derrick International are specialist distributors of LV, MV & HV Cable Installation, Jointing, Duct Sealing, Substation & Electrical Equipment – servicing UK and global businesses involved in cable installations, cable jointing, substation, overhead line and electrical construction at LV, 11kV, 33kV and EHV.

THORNE & DERRICK Product Categories: Duct Seals | Cable Cleats | Cable Glands | Electrical Safety | Arc Flash Protection | Cable Jointing Tools | Cable Pulling | Earthing | Feeder Pillars | Cable Joints LV | Joints & Terminations MV HV 

MV & HV Cold Shrink | Cable Accessory Failure Modes

MV & HV Cold Shrink | Cable Accessory Failure Modes

MV & HV cold Shrink

What is Cold Shrink for Medium and High Voltage Cables?

Developed in the 1970’s by 3M, MV & HV Cold Shrink technology has been found to be safer, more reliable and easier to install for the jointing, terminating and abandoning of power cables.

3M Cold Shrink is made from either EPDM (Ethylene-Propylene-Diene-Monomer) or silicone rubber, that is expanded onto a spiral core. After the cold shrink tube has been placed over the joint or cable termination end, this inner spiral is pulled out. The insulating tube then contracts to its pre-stretched size and shrinks onto the cable, exerting constant radial pressure for the lifetime of the joint or termination.

Cold Shrink Offers the Maximum Mechanical Protection

Cold shrink products have a 45+ year track record of performing exceptionally well in indoor and outdoor environments, including under harsh conditions.

The silicone material conforms well to cable bends, which ensures long term reliability against moisture ingress, or voids within the installation. It is shows excellent performance in the following environments:

• Refineries
• Coastal environments
• Altitude
• Dusty environments eg. solar power plants, wind farms
• Vibrations eg. railroad, subway
• Underwater environments
• Overhead joint applications

Cold shrink

Cable Accessory Reliability

There are a variety of issues that can impact on the reliability of MV & HV cable accessories.

These issues include:

• Improper Accessory Selection
• Difficult to Follow Instructions
• Workmanship
• Number of Installation Steps
• How the Accessory is Delivered to the Cable
• Materials Used to Manufacture the Accessory
• Tolerances & Product Design
• Environment Factors
• Training & Support

Medium Voltage cable accessories

3M Electrical manufacture a range of cable accessories for medium and high voltage cables, including cold shrink, which enable quick and easy installation and efficient operation.

Further Reading

• 66kV Terminations | NEW Stock Introduction for 3M Cold Shrink Cable Terminations
• Stress Control | MV Cable Terminations by 3M Electrical
• Cable Jacket Repair | 3M Electrical Webinar

3M – DISTRIBUTORS, STOCKISTS & SUPPLIERS

Thorne & Derrick provide competitive prices and fast delivery from stock for the complete range of 3M Scotchcast and Cold Shrink cable joints, terminations, resins and Scotch electrical tapes – we stock high voltage cable joints and terminations manufactured from 3M using Cold Shrink for 11kV and 33kV cables.

Thorne & Derrick

LV, MV & HV Jointing, Earthing, Substation & Electrical Eqpt

Thorne & Derrick International are specialist distributors of LV, MV & HV Cable Installation, Jointing, Duct Sealing, Substation & Electrical Equipment – servicing UK and global businesses involved in cable installations, cable jointing, substation, overhead line and electrical construction at LV, 11kV, 33kV and EHV.

THORNE & DERRICK Product Categories: Duct Seals | Cable Cleats | Cable Glands | Electrical Safety | Arc Flash Protection | Cable Jointing Tools | Cable Pulling | Earthing | Feeder Pillars | Cable Joints LV | Joints & Terminations MV HV