3M Cable Joints & Terminations
Cable Sealing with 3M Scotchcast Resin
February 14th, 2025
Cable Sealing with 3M Scotchcast Resin
3M Electrical Liquid Resin 2123
3M Scotchcast Resin 2123 is a two-part, unfilled polybutadiene resin designed for temperature curing – the resin from 3M Electrical offers the following features, consistent across the full range of 3M Scotchcast Electrical Liquid Resins: this re-enterable resin is ideal for low voltage cable sealing and insulation in electrical boxes. It comes with the Easy Dispenser 250, ensuring a cleaner application with reduced waste.
The 2123 Resin is formulated for virtually every electrical application requiring a soft, re-enterable resin with good handling and performance characteristics up to 1000 Volts.
Contact us for 3M Electrical technical support, specification guidance or assistance on the selection of electrical insulating resins for all LV MV HV applications.

3M 2123
Scotchcast Electrical Liquid Resins
Typical Property Data – Room Cures
- Polymer Cure/Cured Form/ Filler/Colour – Polybutadiene Room-Temperature Soft, re-enterable Unfilled Translucent Amber
- Temperature Class – 0
- 3M Electrical Liquid Resin Product Number – 2123
- Mixing Ratio – Wt 1:1 Vol (%) 48:52
- Viscosity at 23°C (73°F) (Centipoise) – A = 350-750* B = 700-1400*
- Cure Schedules (Temp/Time) – 21°C (70°F) 24 hrs.
- Gel Time – 62 min
3M Scotchcast Re-Enterable Electrical Insulating Resin 2123 is a soft, two-part polybutadiene resin designed for cable splice protection. It offers excellent handling and performance features and is formulated to be re-enterable for splice sealing. This versatile resin bonds effectively to most cable jackets while providing moisture sealing.
The resin is characterised by good wetting properties and low viscosity, ensuring ease of application. It cures at room temperature and functions as an insulating material for cable splices up to 1 kV. Its flexible, soft nature allows it to flow smoothly, even at low temperatures, filling enclosures and reducing voids. It is tested in accordance with CENELEC HD 623.S1 (EN50393) standards and complies with 2011/65/EU (RoHS) and 1907/2007/EC (REACH) regulations.
3M Scotchcast Resin Features
- Re-accessibility of the cable connection
- Homogeneous and reliable insulation
- Good adhesion of the resin on cables and on itself
- Excellent protection against water
- Low exothermic reaction temperature (0,6 K raise from 24° C)
- Continuous operating temperature of the resin at 90° C, emergencies up to 130° C
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.
3M Terminations | Surface Tracking on Medium Voltage Cable Terminations
October 4th, 2024Surface Tracking – 3M Medium Voltage Cable Terminations
Surface Tracking on Cable Terminations
Surface tracking is the irreversible damage and degradation on the surface of a medium or high voltage cable accessory or insulative material, such as a cable termination, due to the formation of conductive, carbonized paths.
Tracking results when discharges cause carbon to be left on an insulating surface as a result of the degradation caused by the heat of the discharge. This carbon deposit will grow to eventually create a continuous conducting path, which will lead to catastrophic failure.
Cold Shrink & Condensation In Medium Voltage Switchgear & Cable Terminations
Hydrophobic silicone Cold Shrink terminations provide excellent performance in Medium Voltage electrical equipment, such as switchgear, where cables endure temperature fluctuations caused by thermal cycling when under load – this “heating and cooling” effect condensates potentially causing premature partial discharge at the cable termination point. 3M Cold Shrink technology has a material tendency to reject and repel moisture accumulation and thereby reducing the probability for discharge-initiated erosion and tracking on medium/high voltage cable terminations.
N2XS(F)2Y Cable Terminations 12/20 22kV 24kV
Energising Data Centres | The QTIII range of MV Terminations are approved and in widespread service throughout the data centre sector for 12/20 (24)kV connection of N2XS(F)2Y Medium Voltage Cables with XLPE Insulation, Copper Wire Screen and Stranded Copper Conductor to BS EN 60228 into electrical switchgear equipment.

Surface Tracking Causes
Carbonized paths can occur from the dielectric breakdown of insulation, and/or by the introduction of contaminants on the surface that allow for electrical discharges across the surface.
The 3 factors that enable surface tracking to occur on cable terminations (MV HV):
Contamination |
Moisture |
Voltage |
| Dirt/Dust | Rain/Mist/Snow | Electrical Stress |
| Salt | Condensation | |
| Chemicals | Fog | |
| Pollutants | Humidity | |
| Other particulates |
Hydrophobicity
3M Terminations | Protecting Against Tracking
Tracking is defined as a process that produces localised irreversible deterioration on the surface of an insulator, resulting in the loss of the insulating function by the formation of a conductive path on the surface of the insulator.
Silicone is an excellent track resistant material and is hydrophobic, repelling water and making the insulator self-cleaning which results in a dryer surface and lower leakage currents. 3M outdoor cable terminations include 3M rain sheds which disrupt any wet leakage paths that occur in industrial environments and also allows the creepage distance of the termination to be much shorter.
Insulator Skirts
Use of skirts on cable terminations increases the creepage distance (leakage distance) between the voltage source and ground plane. The undercut skirts disrupt wet leakage paths that occur in outdoor environments.
![]()
Advanced Materials
Insulators and skirted assemblies are made of formulated silicone rubber, which has excellent tracking resistance and hydrophobic properties. Special High K materials formulated to effectively control electrical stress.
![]()
Effective Stress Control
Electric field stresses are distributed in a controlled manner along the entire termination length. Voltage stress concentrations on the insulator surface are kept below 15 V/mil at rated voltage.
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.

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
Thorne & Derrick Certificated by 3M for Medium Voltage Training & Product Familiarisation
August 20th, 2024
Thorne & Derrick have successfully hosted the 3M Electrical “Train the Trainer” Programme and are now the first Certificated UK Distributor for this innovative scheme introduced to support MV Cold Shrink Cable Accessory installation competency.
T-t-T has been conceived by 3M to empower their Approved UK Distributors to deliver Product Training and Demonstrations to customers and ensure the highest levels of installation quality and safety are achieved – reducing cable failures, increasing reliability and securing both the revenue and reputation of asset managers and owners.
We had the privilege of welcoming industry expert Allan Russell (Application Engineering Specialist at 3M United Kingdom) who provided excellent tuition and guidance to our team of Technical Sales Engineers on the installation process of 11/33/66kV Cold Shrink Joints and Terminations.
The focus for the 2 days intensive session was the advancement of education, skills and technical knowledge for our Sales Team to best support the Medium Voltage Cable Accessory requirements of all industries – we covered all practical aspects of Cable Preparation & Accessory Installation for the 3M Cold Shrink ranges of Joints & Terminations covering voltage classes 11kV, 33kV and 66kV.
“The Train-the-Trainer concept enables Thorne & Derrick, as a Specialist Distributor for 3M Electrical since 1985, to bolster our customer service and field support to clients and is the perfect complement to our recent appointment as Approved 3M Electrical Kitting Partners – this is a further formidable personal achievement for Jonny Hewitt and another business accolade for Thorne & Derrick,” comments Chris Dodds (Sales & Marketing Manager – Thorne & Derrick).


Rail Electrification Innovation | The next-generation of 25/45/52kV Network Rail PADS ColdShrink Joints with Concentric Neutral, stocking at Thorne & Derrick.


Further Reading
- Thorne & Derrick Electrifying Industry With 3M
- Thorne & Derrick Appointed 3M Electrical Kitting Partners

Thorne & Derrick are Specialist Distributors to EPC’s & Contractors working on the design, construction and maintenance of UK, European and international projects supplying an extensive range of LV HV Cables, Accessories Jointing, Substation & Electrical Eqpt – this includes Hazardous Area (ATEX & IECEx Certified) Equipment to provide Power, Heating & Lighting to the Potentially Explosive Atmospheres industries.
Based in the UK, we are highly customer responsive and absolutely committed to providing a world-class service.
Since 1985, we have provided expert technical support and express delivery from extensive UK stocks to world-wide destinations.
Renewable Energy Energisations at Medium Voltage with 3M Electrical
July 30th, 2024MV Power
Reliable Solutions for Renewable Electrical System Installations
Since 1985, Thorne & Derrick have been Authorised Distributors for the 3M Electrical range of Low, Medium & High Voltage Cable Accessories for the insulation, connection, repair and provision of reliable electrical power up to 66kV utilising Cold Shrink, heat shrink, Scotch Tape and Scotchcast Resin technologies.
For more than 30 years, 3M Electrical has been committed to delivering comprehensive solutions tailored to the needs of challenging renewable energy projects, including wind farms, solar farms, and battery energy storage systems.

3M understands the pivotal role that well-designed and dependable electrical installations play in maximising the benefits of renewable energy sources. As energy demands increase and circuits operate at high capacities, minimising downtime becomes essential for maintaining efficiency and productivity.
To address these challenges, 3M offers a comprehensive range of easy-to-install and reliable electrical solutions across Low, Medium, and High Voltage applications. Their products are designed to withstand the rigours of modern energy systems while ensuring optimal performance.
Together, we can collaborate with you to provide strong technical support, training and customised product kits to help you keep your system running.
Power Cable Accessories
Easy-to-install, reliable solutions

3M™ Cold Shrink Medium Voltage splice kit QS200 12-36 kV |
Designed from the ground up, these medium voltage cable splices are one of the pinnacles of 3M’s performance, quality and reliability these kits are used with 1-core and 3-core cables, armoured or non armoured. No special cable jointing tools, torches or other heat sources needed. |
| Designed using a unique Cold Shrink delivery system. Products are supplied pre-stretched on a removable core for efficiency and ease of installation. Electrical field control device pre-installed in the insulation body help to avoid complexity during the installation. The specific properties of the insulating silicon body allow to terminate wide range of cable cross sections.
3M™ MV termination kits are available both with and without mechanical lugs included. 3M™ QT-III Termination is a further development of the QT-II. It has similar functionality but offers additional advantages for the end user. The main advantages of the QT-III Termination are that it contain fewer individual components. This eliminates time-consuming installation steps, which leads to fewer chances of error. |
![]() 3M™ Cold Shrink Medium Voltage Termination QT-II 3M™ Cold Shrink QT-III Termination Kit 12-36 kV |
![]() 3M™ Separable Connector Kit 12-36 kV |
The Separable Connector is used to establish the connection between the cable and switchgear, transformer or other equipment. Products are moulded using high quality EPDM and sold in packs of 3 phases and they come with stress control element, earthing set, mechanical cable lug and assembly instructions. The straight, elbow and T-plug connectors cover a wide range of cable cross sections. All kits are fully type tested to Cenelec HD 629.1 (DIN VDE 0278). |
| 3M™ Cold Shrink Connector Insulators are useful as primary electrical insulation for all solid dielectric (rubber and plastic) insulated wire and cable splicing rated to 1000 V, both indoor and outdoor. They are often good in providing physical protection and environmental sealing for communication and other non-electrical applications, including sheath repairs. Operating temperature range is -40°C to 90°C. In applications where the product is continuously exposed to UV radiation it is good to overwrap with e.g. Scotch® Super 33+™ Vinyl Electrical Tape or Scotch® Self-Fusing Silicone Rubber Electrical Tape 70. |
![]() 3M™ Cold Shrink Connector Insulators 1000 V |
![]() 3M™ Cold Shrink High Voltage Splice kit QS3000 72.5 kV |
3M™ Cold Shrink High Voltage Splice QS3000 Series Kits are designed for inline splicing up to 72.5 kV Umax Voltage class, 1-core XLPE Crossed Linked Polyethylene cables systems with copper wire screen, lead sheath or aluminium sheath according to IEC 60840. |
| 3M™ Cold Shrink High Voltage Termination QTEN Series Kits. 1-core copper wire, lead sheath or aluminium sheath screened cables. The product options cover power cables up to 2500 mm² in size. The QTEN series, is designed for XLPE Crossed Linked Polyethylene cables up to 72.5 kV (U_max) according to IEC 60840. The kit includes silicone Cold Shrink body with integrated silicone rain sheds with a separate Cold Shrink stress control tube. Silicone Cold Shrink tubes are included to seal on cable lug and cable sheath. The creepage current collector is included for a defined earth potential at the end of the rain sheds. | ![]() Cold Shrink High Voltage Termination kit QTEN Series 72.5 kV |
3M™ Sensored Cable Accessories (SCA) |
3M™ Sensored Cable Accessories (SCA) are Medium voltage cable accessories including accurate current and voltage sensors to support the grid automation. It provides high accuracy voltage, current and phase angle with real time measurements when connected to secondary equipment, like RTUs or protection relays, at the medium voltage secondary substation. Moreover with a capacitive voltage sensor, the accessories provide reliable measurements over a wide temperature range and capable to capture up to the 50th harmonic (2500 Hz), offering a unique way to measure key parameters on the grid for use in prominent use-cases such as Real time monitoring, Fault detection and location, Voltage regulation and volt-var optimisation, Power quality management and Asset health. |

Insulation, Connection and Termination Solutions for Renewable Electrical System Installations
3M™ Locating and Marking System
3M™ Locators and Markers provide a complete system for locating, marking and mapping vital underground assets. From markers that give an exact path and estimated depth of underground utilities, to markers that store information, to utility locators that interface with GPS/GIS field mapping instruments, 3M offers the precision tools needed to manage your assets.
![]() |
![]() |
![]() |
| 3M™ Path Marking Tape | 3M™ EMS and iD Ball Marker | 3M™ Dynatel™ Locator XE Series |
Cable Jacket Repair
![]() |
![]() |
| Scotch® Cable Jacket Repair Tape | 3M™ Heat Shrink Tubing HDCW |
Other Supplies
![]() |
![]() |
![]() |
| Vinyl Electrical Tape | Rubber Electrical Tape | 3M™ Scotchflex™ Cable Tie |

Thorne & Derrick are Specialist Distributors to Solar EPC’s & High Voltage Jointing Contractors working on the design, construction and maintenance of UK, European and international projects supplying an extensive range of LV HV Solar Cables, Jointing, Substation & Electrical Eqpt. Based in the UK, we are highly customer responsive and absolutely committed to providing a world-class service.
We stock LV HV Cables, Accessories & Electrical Equipment to enable the construction, maintenance and operation of utility-scale PV installations – our products connect 600V/1500V solar cables into combiner boxes, inverters, transformers and energise switchgear up to 33kV/132kV for high voltage grid connections. Since 1985, we have provided expert technical support and express delivery from extensive UK stocks to world-wide destinations.

Thorne & Derrick Appointed 3M Electrical Kitting Partners
July 30th, 2024
PR | Uploaded 18.7.2024 by Chris Dodds - Sales Marketing Manager at Thorne & Derrick
Thorne & Derrick have been appointed as the Approved Medium Voltage Kitting Partner for 3M Electrical – this significantly strengthens our ability to lead the market through the innovation and delivery of cable-customised Joints & Terminations for MV applications.
Our Kitting Partnership facilitates the design and distribution to customers on short lead-times of 11kV, 33kV and 66kV Cable Accessories, utilising Cold Shrink Technology developed by 3M Electrical over 40 years ago.
Cold Shrink Technology is track-record proven to deliver the highest levels of electrical reliability and safety for the jointing, termination, abandonment and repair of Low, Medium & High Voltage Cables – ensuring optimum uptime through resilient power cable systems with a safe flame-free installation and a component design that reduces the scope for installer error to the absolute minimum.
“We are delighted to welcome Thorne & Derrick as a new kitting partner and look forward to continued joint success and growth. Being a kitting partner enables tailored solutions for our end customers, which allows us all to meet demands for specifications and react more quickly to dynamic timeframes” Jenny Swindells | Regional Division Leader, Northern Europe
Customisation, As Standard
As a leading UK Specialist Distributor of MV Cable Accessories, Thorne & Derrick deliver from stock the most extensive range of industry standard Joints & Terminations to connect and energise cables to oil, air or gas insulated switchgear, transformers, motors and overhead lines up to 66kV.
The Renewable Revolution and Digital Economy have accelerated pressure on industry to develop project specific Cable Accessories compatible with diverse and evolving cable specifications – our Kitting Partnership with 3M empowers Thorne & Derrick to design tailored MV Connection solutions to the electrical power industry.
This includes customer specific MV Joints & Terminations to UK DNO, National Grid, TfL and Network Rail engineering requirements.
You can now work with us to overcome challenging supply-chain bottlenecks; we keep pace with your project programme and connection commitments so together we energise on-time, everytime.
Resilient & Reliable HV Power Systems

Thorne & Derrick’s EPC Framework Agreements and our Approved Vendor Listing with major project delivery contractors has led to outstanding growth in the Renewables, BESS, Rail, Data-Centre and Explosive Atmosphere sectors.


Pictured | Jonny Hewitt (Sales Engineer | Medium & High Voltage Projects) pictured with Allan Russell (3M Trainer) having successfully completed and achieved 3M Authorised Trainer Certification up to 66kV.

Kitting & Stocking Commitment | Thorne & Derrick have expanded existing stock lines and introduced products into stock across the 3M Electrical Product range from LV to HV. From Scotch Tapes for 600V repair to QTEN for 66kV termination – we hold the deepest and broadest selection of 3M Scotch, Scotchcast and ColdShrink cable accessories in UK stock.

Rail Electrification Innovation | The next-generation of 25/45/52kV Network Rail PADS ColdShrink Joints with Concentric Neutral, stocking at Thorne & Derrick.
5 Steps
Thorne & Derrick with 3M Electrical have identified and introduced 5 Steps to the industry to redefine customer-service excellence.
Our shared objective is a “best-in-industry” service provision to customers.
We are Electrifying your Power.

Thorne & Derrick are Specialist Distributors to EPC’s & Contractors working on the design, construction and maintenance of UK, European and international projects supplying an extensive range of LV HV Cables, Accessories Jointing, Substation & Electrical Eqpt – this includes Hazardous Area (ATEX & IECEx Certified) Equipment to provide Power, Heating & Lighting to the Potentially Explosive Atmospheres industries.
Based in the UK, we are highly customer responsive and absolutely committed to providing a world-class service.
Since 1985, we have provided expert technical support and express delivery from extensive UK stocks to world-wide destinations.

Did you know 3M has some of the industry’s most outstanding performance metrics? Cold Shrink Reliability Record Low Failure Rates*: – 0.067% for Cold Shrink Cable Joints/Splices – 0.022% for Cold Shrink Terminations. *Data based upon U.S. failure data of U.S. manufactured 3M Cold Shrink MV HV Cable Accessories between 2009 and 2012.

Kitting Partner | 3M Medium Voltage Cable Joints & Terminations

















