Frequently asked questions (FAQ)
- All
- About Lovink Enertech
- High Temperature Cycling
- Renewable Energy
- Transition Connections
- Waterlogged Areas
A PILC to XLPE transition cable joint is a medium voltage joint used to connect paper‑insulated lead‑covered (PILC) cables to modern XLPE cables within the same network. It is typically applied during phased cable replacement or network upgrades. The joint must bridge insulation systems with very different electrical and ageing behaviour, which makes correct selection and installation critical.
Incorrect identification of cable type, insulation system or construction can result in the selection of an unsuitable transition joint and increased failure risk.
A transition joint is required whenever two cable systems differ in insulation technology, construction, generation or material characteristics.
That they are “just another cable connection.” In reality, they are often the most technically demanding connection points in mixed-generation MV networks.
They allow utilities to continue using healthy legacy assets while gradually integrating newer cable technologies, helping balance investment and reliability.
Not always. Reliability also depends on how the new cable is connected to the existing network. Poor transition interfaces can introduce new failure risks.
Absolutely. Every phased cable replacement project creates transition points that can influence long-term network reliability.
Potential indicators include:
- Increasing diagnostic activity
- Partial discharge measurements
- Insulation performance changes
- Repeating faults at the same location
Many issues, however, remain hidden until failure occurs.
Because they connect two different cable systems in one location. A failure can interrupt power supply even when the connected cable sections remain intact.
By selecting proven jointing systems, ensuring proper installation training, applying consistent procedures and validating solutions for the actual operating environment.
Laboratory testing validates technical compliance under controlled conditions. Field performance reflects how a transition joint behaves over decades under real operating conditions.
Key considerations include:
- Long-term reliability
- Sealing performance
- Electrical stress control
- Installation consistency
- Proven field performance
No. Transition joints can also be used to connect other cable types that differ in construction, insulation technology or generation.
As utilities replace old cable sections step-by-step, transition joints become essential connection points between legacy and modern infrastructure.
When properly selected and correctly installed, transition joints can deliver a service life that aligns with the remaining life expectancy of the connected cable systems.
Long-term sealing prevents moisture from entering the joint throughout its service life. Once moisture penetrates critical interfaces, degradation may start.
Yes. Transition joints are commonly installed in buried medium-voltage networks and are designed to operate reliably after installation without direct access.
Partial discharge is a localized electrical phenomenon that can slowly damage insulation materials and eventually lead to cable joint failure.
Moisture can reduce insulation performance, initiate electrical degradation and create conditions for partial discharge within the joint.
Important factors include:
- Groundwater exposure
- Soil conditions
- Flooding risk
- Temperature variations
- Accessibility after installation
Yes. Field investigations frequently identify installation-related issues as a significant contributor to long-term transition joint failures.
Installation quality is one of the most important success factors. Even a well-designed joint can underperform if installation procedures are not followed correctly.
Many degradation mechanisms develop gradually. Moisture ingress or insulation deterioration may progress internally long before an outage becomes visible.
Yes. Because the insulation systems differ significantly, moisture can influence the two cable types differently. The transition joint must account for these differences.
Yes. Straight-through joints connect similar cable types, while transition joints must accommodate different insulation systems, materials and ageing mechanisms.
Yes. In many cases both connected cables remain fully functional while failure develops inside the transition joint itself.
Stress control manages the electric field around the connection area. Proper stress control prevents local electrical stress concentrations that can lead to insulation breakdown.
Interfaces combine different materials and electrical characteristics. If sealing, insulation or stress control is compromised, the interface becomes a natural weak point for degradation.
The main risks are:
- Moisture ingress
- Interface degradation
- Insufficient stress control
- Installation errors
- Long-term ageing effects
These risks are concentrated at the transition between cable technologies.
Yes. Many utilities operate mixed networks where older PILC cables remain in service alongside newer XLPE installations. Transition joints enable phased replacement without renewing the entire cable route.
PILC and XLPE cables have different electrical properties, moisture behaviour and ageing characteristics. A transition joint must safely manage these differences within one connection.
A transition cable joint is required when two cable types with different insulation systems, constructions or generations need to be connected within the same medium-voltage network.
In ageing MV networks, transition cable joints are often among the most critical points, because they combine different materials and ageing mechanisms. While cables themselves can have long service lives, failures frequently originate at transition interfaces. This makes transition joints a key focus area for improving long‑term network reliability.
A straight‑through joint connects similar cable types, with the same insulation system and construction. A transition cable joint connects different cable generations or insulation systems, such as PILC and XLPE. Transition joints are more complex because they must manage differences in electrical behaviour, ageing and moisture sensitivity within one joint.
The service life of a medium voltage transition cable joint depends on joint design, installation quality and environmental conditions. When correctly selected and installed, transition cable joints are expected to perform reliably for several decades, often matching the remaining life of the connected cables. Installation quality and long‑term sealing are decisive factors.
Transition cable joints usually fail due to interface‑related issues rather than conductor problems. Common causes include moisture ingress, insufficient stress control and installation errors at the transition between different cable types. These effects often develop over time, which is why failures can occur years after installation.
High temperature cycling refers to the repeated heating and cooling of cable systems caused by changing electrical loads.
Common causes include intermittent renewable energy generation, load variability and grid switching operations.
Modern grids experience more variable load patterns than traditional networks due to renewable energy integration and changing electricity demand.
A thermal cycle is a complete sequence of heating and cooling within a cable system caused by fluctuating electrical loads.
Thermal cycling has become a structural characteristic of modern grids and can influence the long-term performance of cable systems and accessories.
Thermal cycling causes repeated expansion and contraction of materials, creating mechanical and thermal stresses within the system.
Temperature fluctuations can create stress at material interfaces, influencing insulation performance and long-term reliability.
Research shows that the interaction between thermal variation, mechanical stress and material behaviour determines how cable joints degrade over time.
Differences in expansion and contraction can create internal mechanical stresses, particularly at critical interfaces within a cable joint.
Yes. Over time, thermal cycling can contribute to insulation degradation and the development of voids within the system.
Material interfaces are locations where mechanical and thermal forces interact, making them important factors in cable joint performance.
Research shows that repeated temperature fluctuations can contribute to degradation mechanisms that affect long-term cable joint performance.
Thermo-mechanical stress is the combination of thermal expansion, contraction and the resulting mechanical forces within a cable system.
Repeated thermal variation can increase internal stresses, influence interface behaviour and contribute to ageing processes.
Void formation refers to the development of small gaps within a cable joint, which may occur as materials respond to repeated thermal cycling.
Research has shown that pressure at material interfaces changes during thermal cycling, influencing long-term joint performance.
Accelerated ageing refers to degradation processes that occur more rapidly due to repeated operational stresses such as thermal cycling.
Traditional testing methods are often based on steady-state conditions and may not fully represent modern dynamic load profiles.
Thermal cycling can be assessed through extended cycling tests, combined stress testing and long-term ageing simulations.
They provide a more representative view of how cable systems perform under variable operating conditions.
Testing that resembles real-world grid behaviour provides a more accurate understanding of long-term system performance.
Many traditional jointing concepts were developed around assumptions of stable loads and predictable operating conditions.
Temperature distribution influences thermal gradients, mechanical stress levels and long-term degradation behaviour.
Thermal gradients are temperature differences within a cable joint or cable system that can contribute to internal stress development.
Insulation plays a key role in determining how heat is distributed and how the system responds to thermal variation.
Key factors include thermal gradients, internal stresses and long-term material behaviour.
Cable joint performance is influenced not only by the joint itself, but also by cable design, load profiles and operating conditions.
Important factors include cable construction, installation environment, load profile and overall network operation.
As electrical networks become more dynamic, managing temperature variation within cable systems is increasingly important for reliable operation.
Renewable energy is electricity generated from sources such as wind and solar power and supplied to the electricity grid through dedicated energy infrastructure.
Renewable energy projects are installations such as wind farms, solar parks and Battery Energy Storage Systems (BESS) that generate or store electricity and connect to the electricity grid.
A renewable energy grid connection links generation assets such as wind farms, solar parks and BESS installations to substations and distribution grids.
A Battery Energy Storage System (BESS) is an energy storage installation connected to the electricity grid through dedicated electrical infrastructure.
Grid reinforcement refers to upgrading or expanding electricity networks to accommodate increasing renewable energy generation and growing demand for grid capacity.
A collector network gathers electricity from multiple generation assets and transports it to a substation or grid connection point.
Renewable energy projects depend on grid access before electricity can be delivered. Delays in grid capacity or connection approvals can impact project timelines.
Cable joints are critical connection points within the grid. A failure can delay energisation, commissioning and project handover.
Reliable grid infrastructure ensures electricity can be transmitted safely and continuously from renewable energy assets to the electricity network.
Growing renewable generation increases electrical loads, grid connection requirements and the need for network expansion.
Increasing grid congestion, decentralised generation and expanding electricity networks make grid connections more challenging.
Cable joints provide electrical continuity, insulation performance and mechanical protection between cable sections.
Underground cable networks connect turbines to collector systems, substations and grid connection points.
Onshore wind farms often involve long cable routes, fluctuating generation profiles and network expansion requirements.
Cable joints can facilitate new connections, network upgrades and the integration of additional generation assets.
Branch joints connect multiple generation units to a shared feeder or collector cable within the wind farm network.
Large solar parks contain extensive medium-voltage cable networks that require multiple cable connections across the installation.
Fast construction schedules and a high volume of cable connections make reliable project execution essential.
Reliable cable jointing solutions help minimise connection-related issues during testing, energisation and grid connection.
Reliable cable joints help maintain continuous power transmission between the storage system and the electricity grid.
BESS projects often involve compact layouts, varying load profiles and space-restricted installation environments.
Cable joint failures can interrupt the connection between storage assets and the electricity grid, limiting system availability.
Increasing renewable generation creates demand for additional network capacity, infrastructure upgrades and new grid connections.
Cable joints connect new and existing cable infrastructure during network expansion and reinforcement projects.
Cable joints enable renewable assets and network infrastructure to be connected in multiple project phases.
Challenges include grid congestion, limited network capacity and the integration of new infrastructure into existing networks.
Developers can reduce risks through proper planning, suitable cable jointing solutions and validation before commissioning.
Failures can lead to downtime, delayed project handover, repair costs and reduced power generation.
Reliable cable joints help reduce commissioning risks, avoid costly corrective work and support consistent network performance.
Trials allow project teams to validate cable jointing solutions and installation procedures under actual project conditions before full deployment.
Renewable energy assets can only deliver electricity when they are successfully connected to the grid and operating as intended.
Developers can reduce commissioning risks through proper planning, validated solutions and a structured approach to grid connection activities.
Assuming standard installation conditions while overlooking permanent moisture exposure, poor drainage or elevated groundwater pressure.
Not always. If the cable joint remains the weakest link, the overall network reliability may still be limited.
When cable joints are installed in areas with high groundwater levels, recurring flooding, saturated soils or limited accessibility after installation.
Yes. Fewer failures result in lower repair costs, reduced excavation work, fewer outages and more predictable maintenance expenditure.
It refers to cable joints designed to resist moisture ingress and maintain reliable long-term performance under flooded or waterlogged conditions.
Because they are exposed to continuous moisture and may experience hydrostatic pressure while remaining difficult and costly to access after installation.
Installer-friendly designs reduce dependence on perfect installation conditions and help minimise the effect of small installation deviations.
Yes. Issues such as incomplete filling, contamination or insufficient sealing may not become visible until long-term moisture exposure triggers degradation.
Real-world conditions combine moisture, hydrostatic pressure, ageing, temperature variation and installation influences that are difficult to replicate fully in laboratory testing.
Temporary submersion is short-term exposure to water. Permanent moisture exposure means the cable joint remains exposed to groundwater or wet soil conditions for many years.
No. They are also important in areas with high groundwater levels, flood-prone regions, saturated soils, flooded trenches and poor drainage conditions.
Water typically migrates along interfaces rather than through solid materials. Strong adhesion helps prevent moisture from travelling along these pathways.
Air pockets can create moisture pathways and local electrical stress concentrations. This increases the risk of partial discharge and long-term insulation degradation.
Yes. Small defects can create pathways for moisture ingress. In wet environments, water can slowly migrate towards critical interfaces within the cable joint.
A pressure of 2 bar is equivalent to approximately 20 metres of water head. It represents severe underground conditions where water continuously acts on sealing interfaces.
Key considerations include long-term moisture exposure, hydrostatic pressure, interface adhesion, void-free encapsulation, installation conditions and proven field performance.
Not always. Water-resistant may refer to temporary moisture exposure, while flood-resistant implies long-term performance under continuous water exposure and hydrostatic pressure.
Common methods include partial discharge measurements, insulation resistance testing and tan delta measurements. The most suitable method depends on the network and asset-management strategy.
Moisture can migrate slowly along interfaces and gradually degrade insulation performance. A cable joint may continue operating normally while internal degradation develops over time.
Not necessarily. However, it is important to assess whether moisture has reached the sealing system, interfaces or insulation. Because moisture-related damage can be delayed, further inspection or diagnostics may be required.
That the cable itself is usually responsible. In reality, most flooding-related failures originate at joints, terminations and other accessory systems.
Yes. Rising groundwater levels, soil saturation and extreme weather events are increasingly viewed as structural operating conditions rather than exceptional events.
Reliable sealing combined with consistent installation quality. The strongest design can still fail if execution is inconsistent.
By testing performance under realistic site conditions, conducting pilot installations and verifying installation procedures before large-scale deployment.
In many underground installations, joints become difficult or expensive to access after commissioning. Reliability therefore needs to be built in from the start.
Consider:
- Groundwater levels
- Flooding frequency
- Installation environment
- Hydrostatic pressure
- Accessibility after installation
- Long-term sealing performance
Yes. Moisture-driven degradation may spread to adjacent cable sections, potentially shortening the effective lifetime of surrounding assets.
Because joints are buried underground, repairs are costly and disruptive. Reducing joint failures lowers maintenance costs and improves long-term asset performance.
The main benefits are:
- Fewer outages
- Lower repair costs
- Reduced excavation work
- Longer asset life
- More predictable operational expenditure
By preventing water ingress and maintaining sealing integrity, they reduce the likelihood of both immediate and delayed failures.
The degradation process often occurs internally and remains hidden until insulation performance has deteriorated enough to cause an outage.
Continuous moisture exposure accelerates degradation processes, increasing the likelihood of insulation breakdown and reducing long-term reliability if sealing integrity is compromised.
Failure analyses consistently show that joints are the most critical weak point during flooding events. Improving joint reliability often provides a greater resilience benefit than replacing the cable itself.
Differences are often caused by variation in installation methods, site conditions, contractor experience and project execution rather than the jointing technology itself.
An installer-forgiving design reduces dependency on perfect installation conditions and helps lower the risk of failure caused by small installation deviations.
Common issues include:
- Installing in uncontrolled wet conditions
- Incomplete encapsulation
- Poor site preparation
- Using solutions not suited for groundwater exposure
- Inconsistent installation practices
Even the best jointing solution can fail if installation conditions are poorly controlled or critical installation steps are not followed correctly.
Studies show that a significant share of failures is linked to installation issues, moisture ingress and mechanical damage rather than the cable joint design alone.
Lab-proof products meet standard test requirements. Field-proof solutions continue to perform under real-world conditions such as groundwater exposure, mechanical stress and installation variability.
Not always. Laboratory testing cannot fully replicate real-world conditions such as soil movement, fluctuating groundwater levels, contamination and long-term ageing.
By focusing on cable joint reliability, selecting solutions designed for long-term moisture exposure, and validating performance under realistic field conditions.
Typical applications include:
- High groundwater areas
- Flood-prone regions
- Water-saturated soil
- Flooded cable trenches
- Water-filled manholes
Strong adhesion between the joint materials and cable surfaces prevents moisture from travelling along interfaces, which is one of the most common routes for water ingress.
Even small air pockets can become pathways for moisture migration and increase the risk of partial discharge. Complete, void-free filling reduces long-term failure risk.
A water pressure of 2 bar is comparable to approximately 20 metres of water head. It represents severe underground conditions where sealing performance becomes critical.
A joint can be designed to resist long-term water ingress, but performance depends on the complete sealing system, installation quality and long-term ageing behaviour.
Hydrostatic pressure is the continuous force exerted by groundwater or standing water. It pushes moisture into the smallest gaps and weak points in a cable joint over long periods.
Water typically migrates through material interfaces, micro-voids, imperfect seals or installation defects. Once inside, it can gradually reduce insulation performance.
Not always. Moisture-related degradation can develop over months or even years before an outage occurs, making failures difficult to trace back to the original flooding event.
The most common causes are water ingress, insulation degradation, partial discharge, poor sealing, installation defects and long-term ageing under wet conditions.
In many cases, yes. Modern MV cables can tolerate prolonged moisture exposure. Outages during flooding events are typically linked to joints, terminations and other accessories rather than the cable itself.
Medium-voltage cables are designed as continuous insulation systems. Cable joints contain multiple materials, interfaces and sealing points, creating potential pathways for moisture ingress. In flooded conditions, failures therefore occur more often in joints than in cables.
Our mission is to develop cable connections that go further: reliable, easy to install and designed to last for generations. The vision is to strengthen energy networks worldwide with solutions that are ready for heavier loads, climate change and the energy transition.
Lovink Enertech is a Dutch manufacturer and specialist in cable fittings for medium-voltage networks. The company was founded in 1911 and has more than 100 years of experience in developing, manufacturing and supplying innovative and reliable cable connections.
A liquid silicone insulation that provides a homogeneous electric field, excellent moisture protection and a lifespan of at least 40 years.
We offer a wide range of cable joints and accessories for medium voltage (up to 36kV), including: connection joints, transition sleeves, cross-bonding sleeves, branch joints, repair sleeves and end sleeves.
Resin focuses on outer encapsulation and sealing; cold‑shrink focuses on radial pressure insulation without flame. Some joint systems combine multiple protection layers.
Our cable joints can be used up to 36kV.
A resin joint is a cable joint where a two‑component resin is cast into a housing/mould to seal and protect the connection against moisture and mechanical stress.
An innovative cable sleeve with cold-shrink inner sleeve and ABS outer shell, combined with resin for mechanical strength and waterproofing.
On average, the installation of a LoviSil® cable joint takes 45 to 60 minutes, depending on cable type and conditions. Thanks to liquid silicone insulation, no shrinkage or heating process is required.
In MV applications, waterproof performance depends on resin chemistry, interface adhesion, void‑free casting and system validation. Protolin® is designed as a system‑critical sealing barrier in Lovink MV joints.
No, LoviX® R is designed for installation without special tools. Only standard cable tools are required.
Our sleeves are compatible with plastic cables: XLPE, EPR, HPTE and paper insulated cables (GPLK) up to 36kV.
This depends on the type of joint – each joint comes with a pre-measured amount of LoviSil® liquid and Protolin resin.
Yes, our technologies are waterproof and can withstand water pressure up to 2 bar (20 meters) – ideal for wet soil and underground applications.
Yes, provided that the screen wires are correctly connected and shielded according to the installation instructions.
Yes, our solutions are widely used in wind and solar farms and are resistant to common influences and challenges in this market.
Yes, thanks to LoviSil® and Protolin® resins, our joints are resistant to chemicals.
Yes, via Lovink Academy: practical training, video instructions and certification.
Lovink Enertech serves energy companies, industry and renewable energy projects. The largest customers in this are network operators, project developers and contractors.
