Geritel Wire's THHN Wire Has Passed UL Certification

Our THHN wires have successfully obtained UL certification, which is the internationally recognized highest standard for electrical product safety and quality.

UL (Underwriters Laboratories) certification is one of the most recognized safety marks globally, especially in North America, where it is often a mandatory requirement for electrical components used in residential, commercial, and industrial installations.

With this certification, our THHN wires officially comply with UL safety standards (UL 83), meeting the stringent standards of the North American and South American markets.

1. Understanding UL Certification 

UL (Underwriters Laboratories) is a globally recognized independent organization based in the United States that conducts rigorous safety testing and certification for electrical, electronic, and mechanical products.
Earning UL Certification means that a product has been independently tested and verified to meet established safety and performance standards, protecting users from electrical hazards and ensuring long-term reliability.

For electrical cables, UL certification focuses on multiple dimensions of compliance, including:

• Electrical Safety: Ensures insulation integrity, voltage endurance, and resistance to overloads and short circuits.
• Thermal Performance: Evaluates the cable’s ability to withstand continuous operating temperatures (up to 90°C dry / 75°C wet for THHN wire).
• Flame Resistance: Verifies the product’s fire-retardant properties through vertical flame tests and heat distortion analysis.
• Mechanical Strength: Tests the cable’s flexibility, abrasion resistance, and tensile strength to ensure stable performance during installation and use.
• Material Composition: Confirms compliance with environmental directives such as RoHS and REACH, ensuring eco-friendly and non-toxic materials.

By receiving UL certification, our THHN wire is now officially approved for installation in accordance with the U.S. National Electrical Code (NEC) — a major advantage for distributors, contractors, and OEMs operating in North America.

2. About THHN Cables

Our THHN (Thermoplastic High-Temperature Coated Nylon) cables combine superior materials, advanced extrusion technology, and precision manufacturing processes to maintain stable performance even in high-temperature and harsh environments.

Key Features of THHN Cables:

• High Temperature Resistance — Rated at 90°C in dry environments and 75°C in humid environments, ensuring long-term reliable operation in a variety of installation environments.
• Nylon Sheath Protection — The tough nylon outer layer provides excellent abrasion resistance and moisture protection, simplifying conduit installation and extending cable life.
• Excellent Conductivity — Utilizes high-purity copper conductors for maximum efficiency and minimal voltage drop.
• Chemical and Oil Resistance — Reliable operation in industrial environments exposed to lubricants, fuels, and cleaning agents.
• Color Coding and Identification — Offers multiple colors for easy phase sequence identification and complies with National Electrical Code (NEC) wiring standards.

THHN wires are suitable for applications such as conduit wiring, control panels, lighting circuits, mechanical equipment, and building infrastructure, serving both residential, commercial, and industrial markets.

3. THHN Wire Certification Process

THHN wire undergoes a multi-stage certification process involving product testing, documentation, and factory assessment. The certification process includes:

• Prototype Design and Internal Testing: Initial verification of insulation performance, conductor purity, and temperature performance.
• UL Third-Party Assessment: Submission of samples for flame retardancy, tensile strength, dielectric properties, and heat distortion testing according to UL 83 standards.
• Production Process Audit: On-site factory inspection to verify the quality control system, traceability, and material consistency.
• Final Certification and Listing: Upon successful certification, UL issues a formal certification number and authorizes the printing of the UL mark on our product sheaths.

Obtaining UL certification not only enhances the market reputation of THHN wires but also demonstrates our ability to integrate innovation, safety, and compliance into every stage of product development.

4. Geritel Wire's Unwavering Pursuit of Excellence in Wires and Cables

UL certification, while a significant milestone, is not our end goal, but rather the cornerstone of our continuous progress. Our company is committed to product innovation, process optimization, and environmental sustainability. We are expanding our UL-certified product line to include MTW, XHHW, and photovoltaic wires, among other categories. We are dedicated to smart manufacturing technologies to enhance traceability and accuracy. We are strengthening materials research and development to create cables with higher temperature resistance and lower carbon footprints. We are enhancing our global after-sales service and technical support to maximize customer satisfaction.

The successful UL certification of our THHN wire is not merely a technological achievement but a strategic advancement that enables us to serve the global market with greater confidence, enhanced compliance, and a stronger reputation.