Introduction to Low Voltage Gel Joints
What is a Gel?
A GEL is a solid, jelly-like material that can have properties ranging from soft and weak to hard and tough.
It is composed of polymers which are connected by chemical or physical cross-links. Gels do not no flow like liquids when in the steady-state.
Raychem low voltage gels are usually tacky and easy to deform. These properties help to create an environmental seal to protect electrical components from moisture and contamination.
Different gels are used depending on the requirements of their application
How does a Gel work?
- Wets the surface with a thin layer of oil that repels water
- No corrosion without water & oxygen on the contacts
- Is tacky, so it adheres to the contacts and provides an excellent seal against moisture and contaminants
- Can be removed easily if desired
What are the Requirements for LV Gels?
- Excellent sealing capabilities
- Electrically insulating
- Corrosion protection to metals
- Temperature resistant continuously up to 90 °C
- Compatible with used materials:
- Cable jacket and conductor insulation
- Metals of connectors
- Corrosion protection materials
What is Raychem “PowerGel”?
- Silicone oil, which is embedded in a cross-linked silicone matrix
- Combines the advantages of solid and liquid insulating materials
- Solid: Elastic memory
- Liquid: Wetting, conforms to surfaces
What is special about PowerGel?
- Unique tackiness and thermal long-term stability
- Extremely high elongation and elasticity
- Excellent moisture seal from -40 °C to over 90 °C
- Compatible with all common cable jacket materials
- Excellent insulating properties
- Chemical resistant to acids, bases, salt and pollution
- UV resistance
- Fungus resistant
- Excellent ageing properties
- No subject to labelling requirements
What is a Gel filled Cable Joint?
A joint in which the connected cable ends are fully encapsulated in a Gel
- Functions:
- Electrical insulation
- Mechanical protection
- Corrosion protection to metals
- Moisture exclusion
- Temperature resistance
- Components:
- Cable conductor connector
- Gel filled shells
- Tie wraps
- Installation instructions
What are the installation steps?
- Prepare cable and install connector
- osition the closure and snap-close the joint
- Install tie wrapsand switch on power
What can go wrong?
- Water entry (along the cable interface)
- Not enough pressure on the gel (gel needs to come out of the cable entries)
- Inadequate removal of conductor insulation
- Conductors not properly connected
- Joint not properly snap-closed
How are they tested?
Gel Joints are tested in accordance with the European Standard for LV cable accessories EN 50393 (VDE 278)
- Test program includes:
- AC voltage test – 4 kV
- Insulation resistance measurement – 50 MΩ
- Mechanical Impact test – 4 kg from 1m height
- Heating cycle test in air – 3 weeks
- Heating cycle test in water – 1 m for 3 weeks
- AC voltage and insulation resistance in water
- Examination of joint (water entry, cracks etc.)
What are the advantages of Gel Joints?
- Wide application range
- For all common cables
- Simple to install, high reliability
- No tools, no mixing, no pouring, no heat required
- No subject to labelling requirements
- Unlimited shelf life
- Range taking
- Environment-friendly
What can we offer in this market?
- A wide range of cold applied products for LV cable jointing applications
- Products to suit specific markets (e.g. for solar and wind applications)
- In-house design and product management capabilities:
- Gel (resin), enclosures (tools), connectors
Range of TE Products:
GelBox Product Family
GelBox 25 -PowerGel filled cable joints for polymeric cables 0.6/1 kV
- Straight connections
- Including one piece connector block
- Cross sections: 4-5 x 6-35 mm²
- Insulation piercing technology
- Shear bolt technology
GelBox 25 -PowerGel filled cable joints for polymeric cables 0.6/1 kV
- Straight connections
- Including one piece connector block
- Cross sections: 4-5 x 6-35 mm²
- Insulation piercing technology
- Shear bolt technology
GelWrap Product Family
GelWrap – PowerGel filled sleeve for LV applications
- Cable jacket repair
- Inline joint (with compression or mechanical connectors)
- Available in different length and sizes
- Application range:
- Diameter: 4-50 mm
- Cross section: 2,5-240 mm²
What are the installation steps?
- Clean cable and stretch GelWrap
- Position GelWrap and snap-close
- Secure with tie wrapand switch on power
CBO – Cable Breakouts
CBO – Elastomer Cable Breakouts
- Reliable termination of polymeric insulated cables in house connection boxes, lighting poles, switchgear and transformer stations
- Made from UV-stable, thermoplastic elastomer (TPE)
- Easy to install, no tools needed
- Available in different sizes for round and sector shaped conductors
- Application range:
- 3 x 1,5 – 4 x 185 mm²
CEC – Cable End Caps
CEC – Silicone Cable End Caps
- Protection of cable ends against humidity during transportation and outdoor storage
- Made from UV-stable and weatherproof silicon rubber
- Easy to install using lubricant and re-usable
- Available in different sizes
- Application range:
- 3 x 1,5 – 4 x 185 mm²
- 8-54 mm cable diameter
