Silicone Cold Shrink Tubing for MC4 Photovoltaic Connectors

Product Description

Silicone rubber cold shrink tube - special for photovoltaic connectors

Silicone rubber cold shrink tube, specifically designed for photovoltaic connectors, is an insulating sleeve made from special silicone rubber, pre-expanded over a removable support tube. Its very high expansion ratio allows it to accommodate the radial size differences between photovoltaic connectors and optical cables. When in use, simply position it and remove the support tube. It utilizes its radial shrinking force to form a tight encapsulation, providing insulation, dust prevention, waterproofing, and sealing effects

Support customization, ODM & OEM available

Applications for Offshore Photovoltaic MC4 Connectors-UV Resistant, Salt Spray Corrosion Resistant, Waterproof, Sealing

Features:

1. Continuous operating temperature: -55°C～180°C
2. Shrink Ratio : 6:1 or so. Suits for an extensive range of cable sizes because of the shrinkage
3. Retains its resiliency and pressure even after prolonged years of ageing and exposure, seals tight against moisture and water
4. Good weather resistance, ozone ageing, ultraviolet and salt mist corrosion resistance, performs stably under long-period exposure to the sun
5. Simple installation, requires no special heating tools, and adhesive to seal the connections
6. Standard color: black - Other colors can be customized

Click chat now to contact us for free samples

VR

Technical Performance

Properties	Typical Data	Test Method
Hardness	40±5	GB/T 531-2008
Tensile strength	≥7.0MPa	GB/T 528-2009
Tensile strength after aging MPa - 232℃×7 D	≥ 60% of initial value	/
Elongation at break	＞800%	GB/T 528-2009
Elongation at break after aging % - 232℃×7 D	≥25% of initial value	/
Tear strength	≥25kN/m	GB/T 529-2008
Volume resistivity	≥10 12Ω/m	/
Flammability	HB	UL 94
Requirements for UV/ light aging resistance test	Tensile strength ≥75% of initial value, no surface damage	/

Structure

Dimensions

Size	Inner Diameter - mm	Min Cable Outer Diameter - mm	Max Cable Outer Diameter - mm	Full Recovered Length - mm
VS-25*220	Ф25	6.0	20.0	220
	Ф25	6.0	20.0	175
Note: Special sizes & packing are available on request

Company Show

Suzhou Volsun Electronics Technology Co., Ltd. was founded in 2006. We keep focusing on the R&D, production and sales in insulation, sealing & protection solutions for over 20 years

Quality is our culture. Volsun has a modern quality management system, which has passed a series of quality system certification such as IATF16949, ISO9001 etc

Up to now, Volsun cooperated with customers from 88 countries, we offer suitable sealing, waterproof solutions for some well-know enterprises in communication, Automobile, Power industry etc

Quality Assurance

Our management and employees are committed to providing the highest quality products and services. This ongoing commitment is recognized through ISO9001, ISO14001, ISO45001, IATF16949, UL, ROHS, and REACH certifications. We employ rigorous quality assurance standards to guarantee our customers the highest quality standards

We also have the ability to be your just-in-time supplier. This helps you keep your production lines running and provides better cash flow management by eliminating inventory requirements

Because every manufacturer has different needs and challenges to overcome, we are committed to providing exceptional service to each of our customers. We will work with you to provide the best solution to meet your needs

Abroad Exhibition

Packing & Delivery

Trade terms	FOB, EXW, CIF, DDU, DDP, CFR
Payment terms	T/T, L/C, Negotiable
Supply capability	1,000,000 pieces per month
Lead time	Usually 2-3 working days
Shipment	Express, Air, Sea
Port	Shanghai, Ningbo, Shenzhen
Sample availability	Yes
Sample time	Usually 1-2 days
Packaging	Normal: Plastic bag & Carton & Pallet Special: Customized packing

FAQ

Q 1. How long is the payment term
A: We accept T/T 50% deposit and 50% balance against B/L or L/C copy at sight, also accept Western Union, VISA and Paypal

Q 2. What is the normal lead time for product orders
A: The average lead time for prototype/first piece is 7~10 days, if tooling is involved, the lead time for production tooling  is 10 days, and the average production time after sample approval is 2-3 weeks

Q 3. What is your standard packaging
A: All goods will be packed in cartons and loaded on pallets. Special packing methods are acceptable when needed

Q 4. Can you tell us the monthly production capacity of your products
A: It depends on the model, we produce more than 1500 tons of rubber materials per month

Q 5. What kind of certificates do you have
A1: We have ISO9001:2015, IATF16949:2016, ISO14001:2015, ISO45001:2018 certified
A2: We have various rubber compounds approved by UL, ROHS and REACH

Q6: How to check the quality of bulk order
A1: We provide pre-production samples to all customers before mass production if needed
A3: We accept third-party inspection, such as SGS, TUV, INTERTEK, BV, etc

Q 7: Can you provide customized service

A: Yes, we accept customization and can produce products in different sizes, packaging, colors according to requirements

Volsun presents an advanced silicone cold shrink tubing solution designed specifically for MC4 photovoltaic connectors, delivering robust protection and long-lasting performance for solar PV installations. As solar arrays expand in size and complexity, safeguarding every connection point is essential to maintain system efficiency and reliability. Our MC4 cold shrink tubing provides a focused, high-performance method for photovoltaic connector protection, ensuring that critical MC4 connections remain insulated, weather-proofed, and mechanically secure over the lifetime of a PV installation.

Product Overview and Purpose

Volsun’s silicone cold shrink tubing is engineered to fit MC4 photovoltaic connectors precisely, creating an immediate and durable seal without heat or special tools. The tubing is delivered in a pre-expanded state on a removable inner core; when the core is removed, the silicone elastomer contracts to form a tight, conformal jacket around the connector body and cable. This cold shrink approach eliminates the need for heat guns, ovens, or open flames on-site, reducing installation time and safety risks while delivering superior photovoltaic connector protection compared with traditional heat-shrink alternatives.

Key Features

- Precision fit for MC4 connectors: The geometry and elastomer formulation are optimized to conform to MC4 housings and cable transitions, ensuring consistent coverage and secure sealing for photovoltaic connectors.

- High-performance silicone elastomer: The silicone compound offers long-term elasticity and resilience, maintaining seal integrity under wide temperature ranges and repeated thermal cycling common in solar environments.

- Simple, tool-free installation: Cold shrink installation requires only removal of the core and placement over the connector, speeding up field operations and minimizing human error.

- Superior environmental resistance: The silicone tubing provides reliable defense against UV radiation, ozone, moisture, dust, and airborne contaminants, delivering comprehensive solar PV connector insulation and weatherproofing.

- Durable adhesion-free sealing: By relying on mechanical compression rather than adhesive tapes or mastic, the tubing avoids adhesive degradation and simplifies eventual removal for maintenance.

- Flexible sizing and lengths: Volsun offers multiple diameters and lengths to accommodate single and paired MC4 connectors, various cable gauges, and different array configurations.

Applications

Volsun’s silicone cold shrink tubing is ideally suited for a broad range of photovoltaic applications:

- Rooftop solar arrays on residential, commercial, and industrial buildings where MC4 connector protection is critical to maintain inverter input reliability.

- Utility-scale solar farms where rapid, repeatable photovoltaic connector insulation is required across thousands of interconnections.

- Off-grid and hybrid renewable systems where long-term durability and weather resistance are essential in remote or harsh climates.

- Maintenance and retrofit projects where installers seek a non-destructive, reversible way to upgrade connection protection without heat or adhesives.

- Marine and mobile solar applications where vibration resistance and moisture ingress prevention are crucial.

Innovation and Technical Advantages

Volsun’s silicone cold shrink tubing leverages material science and design innovations tailored to the demands of solar PV systems:

- Advanced silicone formulation: The tubing’s specialized silicone blends low-temperature flexibility with high-temperature stability, maintaining elasticity from frigid dawns to hot midday peaks. This mitigates micro-gapping and stress that can otherwise lead to moisture ingress and connector corrosion.

- Engineered compression memory: The elastomer exhibits high compression set resistance, preserving spring-back properties over many years and ensuring continuous photovoltaic connector protection without needing periodic re-tensioning.

- Optimized wall thickness and duro-meter: Volsun balances mechanical protection and flexibility by tuning wall thickness and hardness (duro-meter). The result is a tubing that cushions mechanical impacts while conforming to irregular surfaces and cable bends.

- UV and ozone stabilization: Stabilizers and antioxidants are integrated into the silicone compound to prevent surface cracking and oxidation, common failure modes for polymers exposed to intense sunlight and industrial environments.

- Non-migratory, non-staining composition: The tubing is formulated to avoid plasticizer migration or staining of connector housings, keeping MC4 connectors clean and ensuring no interference with contact surfaces or labels.

- Low outgassing and inertness: The silicone material is inert and low in volatile components, making it suitable for sensitive electronics and preventing contamination within sealed cable assemblies.

Installation Benefits and Field Considerations

Volsun’s MC4 cold shrink tubing is designed for ease of use on-site. Installers appreciate the predictable, repeatable process: slide the pre-expanded tubing over the MC4 connector assembly, remove the core, and allow the silicone to contract into place. No special training in heat-shrink techniques is required, and because no heat is used, there is no risk of overheating cable insulation or connector plastics. The cold shrink method also reduces labor time per joint, a significant advantage on large-scale projects.

Because the silicone tubing forms a mechanical seal rather than an adhesive bond, inspections and maintenance become straightforward. Technicians can remove and reapply tubing during component replacement without leaving adhesive residue or damaging connector housings. Volsun also supplies clear installation guidance, recommended lengths, and compatibility charts to ensure correct selection for different MC4 variants and cable sizes.

Reliability and Certifications

Volsun manufactures cold shrink tubing to meet rigorous quality standards and to perform under the demanding conditions typical of PV installations. Our product undergoes accelerated aging, UV exposure, thermal cycling, and salt-fog testing to validate long-term photovoltaic connector protection and solar PV connector insulation performance. These tests demonstrate that Volsun silicone cold shrink tubing preserves electrical integrity and prevents moisture ingress far longer than many conventional alternatives.

Environmental and Economic Advantages

By extending the service life of MC4 junctions and reducing maintenance cycles, Volsun’s cold shrink tubing contributes to lower lifecycle costs for solar arrays. The product helps avoid failures that can lead to energy yield losses, inverter faults, or costly field interventions. The non-adhesive, recyclable silicone formulation also aligns with sustainability goals by minimizing contaminant waste and enabling easier component recycling during end-of-life decommissioning.

Why Choose Volsun

Volsun combines material expertise and field-focused design to produce a cold shrink solution that addresses real-world photovoltaic installation challenges. Our silicone cold shrink tubing for MC4 connectors delivers dependable photovoltaic connector protection, efficient solar PV connector insulation, and resilient silicone weatherproof tubing properties in one easy-to-install package. For installers, EPCs, and asset owners seeking to improve uptime, reduce maintenance, and protect PV investments, Volsun’s product offers a practical, long-lasting answer.

For any solar PV project where reliable MC4 connector protection is a priority, Volsun’s silicone cold shrink tubing is an effective, installer-friendly choice. It streamlines installation, resists environmental stressors, maintains durable insulation, and simplifies maintenance operations—resulting in safer, more reliable photovoltaic systems. Choose Volsun’s MC4 cold shrink tubing to ensure your photovoltaic connector protection strategy is robust, long-lasting, and optimized for real-world solar condition