By Eileen Harvey
Tray cables play a crucial role in the infrastructure of commercial, industrial and utility settings, serving as essential conduits for power, control and instrumentation wiring. Given the widespread application of these products, a pertinent question arises among electrical engineers, installers and project owners regarding the suitability of tray cables for environments exposed to direct sunlight. The concise answer is affirmative; however, it is imperative that these cables are not only rated for outdoor use but also manufactured with materials that possess inherent UV resistance. This article delves into the technical aspects surrounding the exposure of tray cables to sunlight, elucidating the materials and certifications that ensure their longevity and performance under such conditions.
Proper installation can mitigate the risks of environmental exposure and extend the lifespan and reliability of the cable. This discourse also answers frequently asked questions, providing clarity on common concerns and helping stakeholders make informed decisions when selecting tray cables. By taking into account the technical specifications and installation guidelines outlined herein, professionals can ensure that their wiring systems remain robust and operational, even in challenging outdoor environments.
Why Sunlight Resistance Matters for Tray Cables
Tray cables are engineered for installation within cable trays or raceways. This makes them ideal for organizing and managing extensive bundles of electrical cables throughout buildings and industrial facilities. These configurations are particularly advantageous in environments that require the seamless integration of multiple cable types while ensuring ease of maintenance and safety. The robust nature of tray cables allows them to withstand physical stress and environmental factors, but their performance can be severely compromised when exposed to harsh conditions. One significant concern arises when these cables are situated outdoors or in partially covered areas where they are subjected to prolonged exposure to direct sunlight. This exposure can lead to detrimental effects on the cables’ materials, primarily due to the ultraviolet (UV) radiation present in sunlight.
Without proper sunlight resistance, cables face three main risks. First is loss of flexibilityꟷsun damage often results in stiff, brittle cables that are hard to install and maintain. The second risk is deteriorated electrical insulation, which can lead to electrical failures, short circuits and fire hazards. The third risk is premature agingꟷsunlight accelerates the breakdown of cable materials, shortening overall cable lifespan and increasing maintenance costs.
Using cables not rated for sunlight outdoors or in exposed areas leads to frequent replacements and unsafe conditions. Therefore, selecting sunlight-resistant tray cables that meet industry standards is critical.
Materials and Ratings for Sunlight-Resistant Tray Cables
Common Sunlight-Resistant Materials
Tray cables designed for prolonged sunlight exposure are built with jackets and insulation made from materials that resist UV damage. Common options include cross-linked polyethylene (XLPE), which provides strong resistance to UV and heat; PVC with UV stabilizers, which incorporates additives to improve outdoor durability; and fluoropolymers such as FEP and PTFE, which deliver superior protection against both UV and chemicals. Some manufacturers also use proprietary UV-resistant compounds formulated to meet UL and NEC sunlight resistance standards. Black jackets are frequently preferred, since carbon black additives naturally enhance UV protection.
Important Industry Standards
Sunlight-resistant tray cables are designed to meet strict industry standards that ensure safe and reliable outdoor performance. Key certifications include UL 1277 (Type TC/TC-ER), which requires jackets marked for sunlight resistance and in some cases direct burial; NEC Article 310.10(C), which specifies environmental and sunlight exposure guidelines for cable installation; and UL 1685, the Vertical Tray Flame Test that verifies flame resistance for tray applications, even in exposed conditions. These cables are typically marked with SUN RESISTANT or SUNLIGHT RESISTANT labels. Leading products such as Okonite’s Type TC cables and SAB Bröckskes TR 600 cables carry these ratings along with additional approvals for oil resistance, direct burial and wet locations.
Installation Considerations for Sunlight-Exposed Tray Cables
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Always verify that the manufacturer has marked the tray cable for sunlight resistance.
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Inspect installation surroundings to assess if UV exposure is intermittent or continuous.
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Use proper cable support and spacing to prevent overheating due to bundling.
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For direct burial, ensure cables are rated accordingly. In necessary, consider additional mechanical protection.
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Follow local electrical codes and AHJ (Authority Having Jurisdiction) requirements.
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Avoid unnecessary exposure by placing cables under covers or conduit where practical.
Frequently Asked Questions (FAQs)
Q1. Can all tray cables be used in direct sunlight?
A. No. Only tray cables specifically rated and marked as sunlight resistant should be used in direct sunlight exposure. Standard tray cables without this rating are likely to degrade rapidly.
Q2. What materials provide sunlight resistance in tray cables?
A. Common sunlight-resistant materials include XLPE insulation, PVC jackets with UV stabilizers and high-performance fluoropolymer jackets (FEP, PTFE). Black jackets often indicate UV protection due to carbon black content.
Q3. Does sunlight resistance mean the cable is also suitable for direct burial?
A. Often cables rated for sunlight resistance are also direct burial rated, but this is not always the case. Confirm the specific cable’s direct burial rating from manufacturer specifications before underground or buried use.
Q4. How does UV exposure affect cable lifespan?
A. UV exposure causes the insulation and jacketing to become brittle, crack and lose protective properties, which may shorten cable life drastically if not rated for sunlight or protected.
Q5: Are there installation best practices for tray cables outdoors?
A. Yes. Even with sunlight-resistant cables, proper cable tray design, spacing and mechanical protection improve performance and safety.
Tray cables can be suitable for direct sunlight exposure, but only if they are explicitly designed, tested and marked for sunlight resistance. Using cables with UV-resistant jackets such as XLPE, UV-stabilized PVC or fluoropolymers ensures durability, safety and compliance in outdoor and exposed installations.
By selecting the right sunlight-resistant tray cable—such as TKD Kabel’s industrial-grade tray cable line—you protect your electrical infrastructure from premature failure and costly downtime caused by harsh environmental exposure.
