Cable insulation and cable protection: properties of insulation and jacketing materials explained
Cable insulation is a decisive factor for the safety and service life of cables and wires in industrial, commercial, and private applications. It protects not only against electrical hazards, but also against mechanical, chemical, and thermal influences. In this article, you will learn everything about the most important properties, materials, and solutions for the insulation and protection of cables.
GOBA supplies insulation materials for cable insulation in electrical engineering and energy applications.
What are the most important cable insulation properties?
Effective cable insulation is characterised by the following properties:
- Electrical insulation: protection against short circuits and current loss
- Mechanical strength: resistance to abrasion, pressure, and tensile loads
- Temperature resistance: functionality at high and low temperatures (for example from -40 °C to 150 °C)
- Chemical resistance: protection against corrosion, moisture, and chemicals
- Flexibility: adaptability to various applications
Which materials are used for insulation?
The choice of material depends on the specific requirements of the application. Below are the most common materials:
1. Polyvinyl chloride (PVC)
Properties: flexible, cost-effective, chemically resistant. Use: electrical installations, household appliances.
2. Polyethylene (PE)
Properties: excellent electrical insulation, low moisture absorption. Use: telecommunications cables, high-voltage cables.
3. Silicone
Properties: heat-resistant up to 250 °C, flexible. Use: applications at high temperatures, machine wiring.
4. Polyurethane (PU)
Properties: mechanically robust, abrasion-resistant, chemically resistant. Use: cables for demanding environments, for example construction or agriculture.
5. Halogen-free materials
Properties: minimisation of smoke and gas generation in the event of fire. Use: public buildings, transport sector.
How does temperature influence the properties of insulation?
High temperatures can soften or decompose insulation materials, while low temperatures can make them brittle and prone to cracking. Materials such as silicone or PTFE remain stable even at extreme temperatures, making them ideal for industrial applications.
How is damage to cable insulation detected and repaired?
Signs of damage
- Visible cracks or abrasion on the cable sheath surface
- Discolouration from chemical exposure or UV radiation
- Exposed conductors indicating mechanical damage
Repair of cables
- Insulating tape: for small cracks and temporary repairs
- Heat-shrink tubing: permanent solution for restoring insulation
- Replacement of the damaged section: for larger damage
Suitable materials for repair
- Insulating tape made of PVC or PU
- Heat-shrink tubing with heat-resistant adhesive
Which solutions exist for special cable insulation applications?
Halogen-free insulations
Offer increased safety in fires because they release no toxic gases. Ideal for public buildings and transport systems.
UV-resistant insulations
Protect cables that are permanently installed outdoors against solar radiation and weather influences.
Chemically resistant materials
For environments with strong chemicals, for example in the chemical industry or agriculture.
Flexibility at low temperatures
Materials such as silicone remain flexible even at temperatures of -40 °C or lower.
Which cable protection measures are required against mechanical and chemical influences?
Mechanical protection
- Protective tubes: prevent abrasion and pressure damage
- Cable hoses: provide additional protection against impacts and mechanical stress
Chemical protection
- Special jacketing materials: such as PU or PTFE, which are corrosion-resistant
- Coatings: for cables in aggressive environments
Protection against UV radiation and corrosion
UV-resistant materials such as PE or special coatings extend the service life of cables outdoors.
How is cabling optimally planned and implemented?
Planning
- Selection of the right material based on environmental conditions
- Consideration of standards such as EN 50575 for fire behaviour of cables
- Definition of cable cross-sections based on current load
Implementation
- Use of cable ducts or protective tubes for mechanical protection
- Ensuring flexibility and correct fastening of the cables
Standards and regulations
Important standards such as DIN VDE 0298 govern the safe installation and selection of cables and wires.
GOBA Takeaway
Choosing the right cable insulation is essential for the safety, efficiency, and service life of cables. By selecting suitable materials, complying with standards, and implementing effective protection measures, you can achieve optimal results regardless of the environmental conditions.