66kV 72.5kV | Power Cables Accessories for Offshore Windfarms

Published 08 Dec 2022

3M Scotchcast Resins – Powerful Cable Joints

Uploaded by Chris Dodds – Thorne & Derrick Sales & Marketing Manager

3M Scotchcast Resin Cable Joints

Selection Factors, Specification Considerations & Applications

Why risk your power supply by installing underspecified cable joints?

A Failed Cable Joint

Since 1985, Thorne & Derrick International have stocked and distributed 3M Scotchcast cable joints. These products have a strong field service record and provide dependable solutions for cable connection and repair.

Scotchcast joints can help repair damaged cables, extend existing circuits and connect new cable installations. They suit several cable insulation types, including XLPE, EPR and PILC.

The main purpose of an LV cable joint is to remove a damaged or faulty cable section. The joint then restores the electrical performance of the cable as closely as possible to its original manufactured condition.

However, choosing the correct low voltage resin cable joint requires careful consideration. Requirements vary between industries, cable types and installation environments.

Before selecting a cable joint, consider the following factors:

Cable function and application
Required cable reliability
Installation environment
Potential consequences of a power outage or downtime

Without the correct specification, standard resin cable joints can become weak points in industrial cable networks.

3M Scotchcast Cable Joints for Multiple Industries

Applications Across Land, Air and Sea

3M Scotchcast resin cable joints provide reliable performance across a wide range of industries. These include:

Construction and infrastructure
Rail and renewable energy
Airfield lighting and port authorities
Offshore and marine
Mining and utilities
Hazardous areas, including oil, gas and petrochemical facilities

The name Scotchcast has become synonymous with cable jointing. Its reputation is built on reliability, quality and dependable performance.

In addition, 3M has developed a comprehensive range of jointing resins for different installation conditions. Available resin properties include:

Fire resistance
Flame retardancy
Low Smoke Zero Halogen (LSZH) performance
Hydrocarbon resistance

Deep Underground: 3M 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.

The flexible design helps maintain the bend radius of cables that are frequently coiled. Furthermore, these submersible cable joints offer seawater resistance.

This makes them suitable for connecting cables to remotely operated underwater vehicles (ROVs), including applications where divers carry out the connection work.

Further reading: Top 10 Deepest Mines in the World

Deep Underground - 3M Mining Cable Joints

Seeing Beyond the Surface – Worker & Site Safety With 3M Cable Joints

The World’s Biggest Coal Mine: Peabody Energy’s operations in the Powder River Basin of Wyoming, USA. Photograph: Mae Ryan for The Guardian.

Offshore Cable Joints

Global oil and gas companies specify 3M Scotchcast resin cable joints for low voltage power, instrumentation and control cables.

The 3M LVI3 resin cable joints are designed for offshore and marine applications. They suit power, instrumentation and control cables, including BS6883, IEEE, UL, UK00A and NEK606 BFOU/RFOU types.

They also accommodate instrumentation cables in pair, triple and quad configurations.

These joints are typically used in Zone 1 and Zone 2 hazardous areas. They help connect low voltage cables used for electricity distribution, power and lighting in potentially explosive atmospheres.

The 3M LVI3 range uses hydrocarbon-resistant technology based on the performance specification of 3M Scotchcast 1402FR.

It also resists degradation from drilling fluids (mud). This resistance is important for offshore topside and shipboard installations, where hydrocarbons and drilling fluids can damage cable joints and contribute to cable faults.

3M: Specified by the Global Oil & Gas Industry

Repairing Damaged Offshore Cables

Offshore cables face demanding operating conditions. Vibration, shock and constant movement on oil and gas platforms can all contribute to cable damage.

Over time, EPR rubber cable sheaths can also deteriorate. In some installations, replacing the entire cable can prove too expensive or even impossible.

3M LVI cable joints offer a solution for repairing damaged offshore cables or creating a complete cable joint. They can help prevent downtime caused by cable faults.

Salt-laden marine atmospheres can also affect cable braiding and conductors, increasing the risk of short circuits.

Furthermore, the wraparound or snap-on two-part mould design allows mid-span cable repairs and joints without disconnecting the cable at the remote end.

For more information, read our guide to repairing damaged cables. It 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 involve difficult working conditions. Jointers may need to work in muddy trenches, restricted spaces and challenging weather.

In the UK, wet weather can make underground cable jointing even more demanding.

3M designs its cable joints with the needs of cable jointers in mind. The shell design provides practical working space and helps simplify installation.

For example, larger 3M cable joint shells allow access for crimping tools and can accommodate mechanical shearbolt connectors.

This can make cable jointing easier in restricted trenches and cable containment systems. The joints also support cross-core and transition jointing between multi-core XLPE and PILC cables.

In addition, the impact-resistant shells are designed to withstand trench backfill. This is useful because backfill materials can contain sharp stones, clay and organic matter.

3M cable joints are designed to cope with demanding installation conditions.

Why the Size of a Cable Joint Matters

The internal working space inside a cable joint shell can affect how comfortably and safely a jointer can complete the installation.

Ample working space helps jointers carry out several tasks, including:

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 are useful for imperial, metric and AWG connections. The additional space can also help when using hydraulic crimp tool heads in restricted working areas.

Is the cable joint shell large enough for crossing phased cores?

Is the Cable Joint Shell Large Enough for the Crossing of Phased Cores?

Performance in Challenging Weather

Offshore cable installations must withstand some of the harshest weather conditions. These can range from hurricanes in the Gulf of Mexico to powerful Atlantic nor’easters.

Closer to home, the UK continental shelf regularly experiences Force 10 storms. These conditions expose offshore assets to extreme wind and wave effects.

Why Choose 3M Scotchcast Cable Joints?

3M Scotchcast low voltage cable joints are designed to make installation simpler, quicker and safer.

When selecting a cable joint, consider the following features:

Safety: 3M’s Advanced Delivery system provides integrated resin pouring. This helps reduce the cable jointer’s exposure to resin vapours and direct skin contact.
Simplicity: The one-piece, wraparound cable joint shell supports straightforward installation. Fewer installation steps can reduce labour time and help improve productivity during scheduled shutdowns.
Reliability: Correct joint selection and installation help reduce the risk of cable faults.

Specify 3M Scotchcast cable joints with the right application, installation requirements and product performance in mind.

3M Scotchcast Resin Advanced Delivery

3M Scotchcast Cable Joint Design and Features

Single-Piece Cable Joint Mould Shell

The single-piece cable joint mould shell helps simplify installation. Jointers do not need to cut or saw the mould to size.

Range-taking foam seals at each end of the shell provide a tight seal around the cable. This adaptable design removes the need to cut and tape the joint shell to fit.

The folding cable mould meets at the top of the joint rather than along both sides. This design helps reduce potential resin leakage paths.

In addition, 3M cable joint moulds resist cracking and breaking at low temperatures. They are also suitable for direct burial.

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 accommodates 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 around cable support rings, particularly when armour wires need careful positioning.

To simplify this process, 3M uses constant force springs for earthing. These springs offer advantages over single-wire earth continuity systems, which can fail if they sit incorrectly within spread wire armour cores.

The flat, soft copper earth braid also helps maintain good electrical contact.

3M Scotchcast Low Voltage Resin Cable Joints

Safe & Sound With Constant Force Springs: Cable joints move and expand due to earth movement and heat from electrical current. Constant force springs respond to this movement and maintain an electrical connection between the steel wire armouring and the earth continuity braid.

Mechanical Connectors

Mechanical connectors provide fast and straightforward conductor connections. They accommodate copper and aluminium conductors in stranded, sectoral and solid constructions.

They also support metric, imperial and AWG conductor sizes.

3M Scotchcast Resin Options

3M supplies high-quality cable jointing resins with good moisture resistance. Each joint kit includes enough resin for the specified application, so there is no need for topping up.

Different resin formulations suit different operating 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 saltwater solution resistance to 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.

3M Scotchcast Premium Low Voltage Inline Resin Cable Joint

Thorne & Derrick: Specialist Electrical Distributor

Thorne & Derrick

LV ♦ MV ♦ HV

Thorne & Derrick distribute a wide range of low, medium and high voltage cable installation equipment. Our products support cable jointing, termination, pulling and installation work.

We serve UK and international customers working across: