3M Scotchcast Cable Joints – Your Cable Circuit Is Only As Strong As Its Weakest Link
Published 25 May 2018
3M Scotchcast Resins – Powerful Cable Joints
Uploaded by Chris Dodds – Thorne & Derrick Sales & Marketing Manager
Selection factors, specification considerations and application notes
Why Choose the Right Cable Joint?
A Failed Cable Joint
Since 1985, Thorne & Derrick International have stocked and distributed 3M Scotchcast cable joints. These joints have a strong field service record and are used to connect, repair and extend existing cable installations.
Scotchcast joints suit a range of cable types, including XLPE, EPR and PILC. They are also used for low voltage (LV) power, instrumentation and control cables.
The main purpose of an LV cable joint is to remove a damaged or faulty section of cable. The joint then restores the cable’s electrical performance as closely as possible to its original manufactured condition.
However, choosing and installing a low voltage resin cable joint requires careful consideration. The right specification depends on the industry, cable type and installation conditions.
Before selecting a cable joint, consider these key factors:
- Cable function and application
- Required cable reliability
- Installation environment
- The potential cost of power outages or downtime
Standard resin cable joints can create weak points in industrial cable networks if the specification does not match the application. Therefore, selecting the correct joint is essential for reliable cable connections.
3M Scotchcast Cable Joints
Applications Across Land, Air and Sea
3M Scotchcast resin cable joints provide reliable performance across a wide range of industries. These include construction, rail, renewable energy, airfield lighting, ports, offshore, marine, mining and utilities.
They are also used in hazardous areas, including oil, gas and petrochemical facilities.
The name Scotchcast has become widely recognised in cable jointing. 3M has developed a range of jointing resins to meet different installation needs.
Depending on the resin selected, the range offers properties such as:
- Fire resistance
- Flame retardancy
- Low smoke zero halogen (LSZH) performance
- Hydrocarbon resistance
As a result, installers can select a suitable resin for above-ground and underground cable applications.
Deep Underground: Mining Cable Joints
3M Scotchcast 82-F cable joints are designed for straight and branch connections on flexible mining and trailing cables. They use flexible, flame-retardant 3M Scotchcast 2131 resin, which carries Mine Safety and Health Administration (MSHA) Acceptance 07-KA060002-MSHA.
These flexible cable joints do not impair the bend radius of cables that are regularly coiled. In addition, the submersible cable joints offer seawater resistance.
This makes them suitable for connecting cables used by divers and remotely operated underwater vehicles (ROVs).
Further reading: Top 10 Deepest Mines in the World
Seeing Beyond The Surface – Worker & Site Safety With 3M Cable Joints
The World’s Biggest Coalmine: Peabody Energy’s operations in the Powder River Basin of Wyoming, USA. 40% of America’s coal comes out of the North Antelope Rochelle Mine. Photograph: Mae Ryan for the Guardian
Offshore Cable Joints
Global oil and gas companies use 3M Scotchcast resin cable joints to connect low voltage power, instrumentation and control cables offshore.
3M LVI3 resin cable joints suit offshore and marine applications. They are designed for power, instrumentation and control cables, including BS6883, IEEE, UL, UK00A and NEK606 BFOU/RFOU types.
They also suit instrumentation cables in pair, triple and quad configurations. Installers typically use these joints to connect cables in Zone 1 and Zone 2 hazardous areas, where they support low voltage power distribution for lighting and other equipment in potentially explosive atmospheres.
3M LVI3 joints offer hydrocarbon resistance based on the specification performance of 3M Scotchcast 1402FR. They also resist degradation from drilling fluids (mud).
This resistance is important for offshore topside and shipboard installations. Hydrocarbons and drilling mud can damage cable joints over time, increasing the risk of cable faults.
3M: Specified By Global Oil & Gas Industry
Repairing Damaged Offshore Cables
Offshore cables face demanding conditions. Vibration, shock and movement on oil and gas platforms can all cause mechanical damage.
Over time, EPR rubber cable sheaths can also degrade. In some installations, replacing the entire cable can prove too costly or may not be practical.
In these situations, 3M LVI cable joints provide a repair or jointing solution for damaged offshore cables. They help restore the cable connection and reduce the risk of downtime caused by cable failure.
Saltwater atmospheres can react with cable braiding and conductors. This can lead to damage and short circuits if the cable does not have suitable protection.
The wraparound or snap-on, two-part joint moulds allow installers to repair or joint cables mid-span. They do not require disconnection from the remote end of the cable.
For more information about cable repair options, read our guide to repairing damaged cables. This also covers solutions such as Cold Shrink tubes.
3M Cable Joints are installed on offshore oil and gas platforms, FPSOs, FPSs, oil tankers and carriers
Designed for Cable Jointers
Image: Lovink.
Cable jointing can be physically demanding, especially in underground trenches and difficult site conditions. Installers may need to work in confined spaces, handle heavy cables and deal with poor weather.
In the UK, wet weather can make these tasks even more challenging. That’s why practical joint design matters.
3M cable joints are designed with cable jointers in mind. For example, large-shell designs provide more room to work and can improve access during installation.
They also allow access for crimping tools and can accommodate mechanical shearbolt connectors.
In addition, the joints support cross-core and transition jointing between multi-core XLPE and PILC cables.
Their impact-resistant shells can withstand trench backfill. This is important because backfill may contain sharp stones, clay and organic material.
Working Space Inside the Cable Joint
The space inside a cable joint shell affects how comfortably and safely an LV cable jointer can work. This is particularly important on demanding sites where access may be restricted.
A larger working area gives installers more room to complete tasks such as:
- Armour bonding
- Cross-core jointing
- Transition jointing
- Conductor connections
Large cable joint shells can also accommodate mechanical shearbolt connectors, such as Pfisterer Sicon. These connectors suit imperial, metric and AWG connections.
Furthermore, the additional space can help installers use hydraulic crimp tool heads in close working areas.
Watch: Is the cable joint shell large enough for crossing phased cores?
Reliable Performance in Tough Weather
Offshore cables must withstand harsh weather and demanding operating conditions. On oil and gas platforms, vibration, shock and movement can place extra strain on cable installations.
Weather conditions can also vary widely. Offshore assets may face hurricanes in the Gulf of Mexico or powerful Atlantic storms.
Closer to home, the UK continental shelf regularly experiences severe North Sea weather, including Force 10 storms with strong winds and waves.
Why Choose 3M Scotchcast Cable Joints?
3M Scotchcast low voltage cable joints are designed to make installation simpler, quicker and safer.
When selecting and specifying a cable joint, consider the following features:
- Safety: 3M’s Advanced Delivery system provides an integrated resin pour. This helps the cable jointer avoid vapour inhalation and direct skin contact with the resin.
- Simplicity: The one-piece, wraparound cable joint shell supports a straightforward installation process. It can also reduce installation time and labour costs during planned shutdowns.
- Reliability: Selecting the correct cable joint helps reduce the risk of cable faults.
Choose and specify 3M Scotchcast cable joints to support safe installation and reliable cable connections.
3M Scotchcast Resin Advanced Delivery
How 3M Scotchcast Cable Joints Are Designed
One-Piece Cable Joint Mould Shell
The single-piece cable joint mould shell helps simplify installation. Installers do not need to cut or saw the mould to size.
Instead, range-taking foam seals at each end of the shell provide a tight seal around the cable. This adaptable sealing system removes the need to cut and tape the shell to fit.
The folding mould meets at the top of the cable joint rather than along both sides. This design reduces potential paths for resin leakage.
In addition, 3M cable joint moulds resist cracks and breaks, even at low temperatures. They are also suitable for direct burial.
Watch: Why don’t I need to cut a 3M cable joint shell to fit the cable?
Armour Continuity and Earthing
3M’s armour continuity earthing system suits several cable constructions, including:
- Aluminium wire armoured (AWA) single-core cables
- Steel wire armoured (SWA) multi-core cables
- Copper and phosphor bronze wire-braided cables
- Lead-sheathed cables
Traditional worm-drive clips can be difficult to fit when armour wires spread around the cable. To make installation easier, 3M uses constant force springs for earthing.
These springs offer advantages over single-wire earth continuity systems. For example, a single-wire system can fail if the wire sits incorrectly among spread armour cores.
Meanwhile, the flat, soft copper earth braid helps maintain good electrical contact.
Safe & Sound With Constant Force Springs: Cable joints can move and expand due to ground movement and heat from electrical current. Constant force springs respond to this movement and maintain a sound electrical connection between the steel wire armouring and the earth continuity braid
Mechanical Connectors
Mechanical connectors provide a fast and simple way to join copper and aluminium conductors. They suit stranded, sectoral and solid conductors.
They also support connections across metric, imperial and AWG conductor sizes.
Resin Selection
3M Scotchcast cable joint kits include high-quality resin with good moisture resistance. Each kit contains enough resin for the specified application, so installers do not need to top up the joint.
Different resins offer properties for specific installation environments:
- Scotchcast 1402FR Resin – Halogen Free: Suitable for public areas where fire, smoke and toxic fumes could threaten people and equipment.
- Scotchcast 1402FR Resin – Hydrocarbon Resistant: Suitable for air-exposed and contaminated ground installations.
- Scotchcast 2131 Resin – Seawater Resistant: Offers resistance to salt water solution in accordance with ISO 175.
Did You Know?
3M Scotchcast resin cable joints are typically used for 600/1000V cables. However, they can be up-rated for 3.3kV cable jointing.
Watch: 3M Scotchcast Premium Low Voltage Inline Resin Cable Joint
Thorne & Derrick – Specialist Electrical Distributor
LV ♦ MV ♦ HV
Thorne & Derrick distribute a wide range of LV, MV and HV cable jointing, terminating, pulling and installation equipment. We support customers across the UK and worldwide.
Our customers work on underground cables, overhead lines, substations, switchgear and electrical construction projects. We supply equipment for LV, 11kV, 33kV and EHV transmission and distribution applications.
Key Products
- MV-HV Cable Joints & Terminations
- Cable cleats and cable transits
- Duct seals and underground cable protection
- Cable jointing tools
- Feeder pillars and cable ducting
- Earthing and lightning protection
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- Arc flash protection and fusegear
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We distribute products from leading manufacturers, including 3M, ABB, Alroc, Band-It, Catu, Cembre, Centriforce, CMP, Elastimold, Ellis Patents, Emtelle, Furse, Lucy Zodion, Nexans Euromold, Pfisterer, Polypipe, Prysmian and Roxtec.
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