Selecting the correct cold shrink tube is just as important as choosing the right MC4 connector. Even a high-quality sealing product may not deliver reliable performance if the size does not match the cable and connector properly.
Here we’d like to explain the key factors to consider when selecting a cold shrink tube for photovoltaic applications.
Start with the Cable Diameter
The first step is to confirm the outer diameter of the solar cable after the connector has been assembled.
A common mistake is selecting the tube based only on the cable size. However, once the MC4 connector is installed, the sealing sleeve must fit over both the connector body during installation and recover tightly around the cable entry after the support core is removed.
For this reason, manufacturers usually specify a recommended cable diameter range rather than a single cable size.
For example, Volsun's VS-25×175 mm silicone cold shrink tube is designed for cable outer diameters from 6 mm to 20 mm, making it suitable for many standard photovoltaic cable assemblies.
Consider the Connector Structure
Although MC4 connectors follow similar design principles, dimensions can vary slightly between manufacturers.
Before selecting a cold shrink tube, it is helpful to confirm:
- Connector body diameter
- Cable outlet diameter
- Length of the area requiring protection
- Whether additional accessories are installed
Choose a Material Designed for Outdoor Use
Photovoltaic systems operate in environments where electrical accessories are exposed to sunlight, rain, dust, and changing temperatures year after year.
When selecting a cold shrink tube, material performance is often more important than price alone.
A silicone rubber cold shrink tube offers several advantages for outdoor solar applications, including:
- Continuous operating temperature from -55°C to 180°C
- Excellent resistance to ultraviolet radiation
- Good ozone aging resistance
- Salt mist resistance for demanding environments
- Reliable waterproof sealing
- Long-term elasticity without requiring heat during installation
Don't Ignore Installation Efficiency
Large photovoltaic projects often involve hundreds or even thousands of cable connections. A sealing solution that saves time on every installation can significantly improve overall project efficiency.
Unlike heat shrink tubing, silicone cold shrink tubes are supplied pre-expanded on a removable support core. Installers simply position the tube and pull out the support core. The tube immediately shrinks to create a secure seal around the cable and connector, without using a heat gun or adhesive.
A Real-World Applications
In one recent photovoltaic project, an EPC contractor in Israel selected Volsun's VS-25×175 mm black silicone cold shrink tube to protect MC4 connector cable entries.
The customer needed a sealing solution that could withstand outdoor exposure while remaining easy to install across numerous cable connections. After reviewing the project requirements, the selected model provided the required cable coverage and simplified installation without the need for heating equipment.
A Simple Selection Checklist
Before ordering a cold shrink tube for your next solar project, check the following:
✔ Confirm the cable outer diameter after connector assembly.
✔ Measure the length of the area that requires sealing.
✔ Select a tube with an appropriate expansion range.
✔ Choose a material suitable for long-term outdoor exposure.
✔ Consider installation efficiency for large-scale projects.
✔ Consult the supplier if your connector design is customized.
Spending a few extra minutes on product selection can help avoid installation issues and improve the long-term reliability of the entire PV system.
Need Help Selecting the Right Cold Shrink Tube?
Volsun offers silicone cold shrink tubes designed specifically for photovoltaic connector protection. If you are unsure which model best fits your application, our engineering team can recommend a suitable solution based on your connector dimensions and project requirements.
- CONTACT TEL: +86-512-66386808
- SALES CONTACT: volsun2006@szvolsun.com