Introduction
Choosing the right electrical wire for your project requires a clear understanding of certifications and performance. At JZD Cable (jzdcable.com), a UL and CSA-certified cable manufacturer, we produce premium THHN&THWN-2 nylon-coated wires. This article breaks down their differences in compliance with waterproof Ratings, temperature limits and applications to guide your selection.
1. Core Specifications of THHN and THWN-2
THHN (Thermoplastic High Heat-Resistant Nylon-Coated)
- Standards: Complies with UL 83 (US) and optionally CSA C22.2 No.75 (Canada) upon request.
- Temperature Rating:
- 90°C in dry conditions
- 75°C in wet conditions
- Construction:
- PVC insulation with heat-resistant additives.
- Outer nylon sheath for mechanical protection.
- Voltage Rating: Up to 600V.
- Applications: Ideal for dry or temporarily damp indoor environments (e.g., control panels, HVAC systems).
THWN-2 (Thermoplastic Heat and Water-Resistant Nylon-Coated)
- Standards: Complies with UL 83 (US) and optionally CSA C22.2 No.75 (Canada) upon request.
- Temperature Rating:
- 90°C in both dry and wet conditions
- Construction:
- PVC insulation with waterproofing additives.
- Thicker dual-layer nylon sheath for extreme moisture resistance.
- Voltage Rating: Up to 600V.
- Applications: Designed for harsh environments (e.g., underground conduits, chemical plants, coastal installations).
2. Key Differences: THHN vs. THWN-2
| Feature | THHN | THWN-2 |
|---|---|---|
| Certifications | UL 83 (CSA optional) | UL 83 (CSA optional) |
| Water Resistance | Suitable for damp locations | Submersion-tolerant |
| Temperature Range | 90°C (Dry) / 75°C (Wet) | 90°C (Dry & Wet) |
| Chemical Resistance | Moderate oil resistance | High resistance to oil, solvents, and UV |
| Ideal Use Case | Indoor machinery, lighting | Outdoor/industrial projects |
3. How to Choose Between THHN and THWN-2?
- For Cost-Effective Indoor Use: Choose THHN when moisture exposure is minimal (e.g., commercial buildings).
- For Harsh or Outdoor Environments: Opt for THWN-2 to meet stricter CSA C22.2 No.75 requirements in wet, oily, or freezing conditions (e.g., Canadian industrial sites).
4. Why Choose JZD Cable’s THHN&THWN-2 Wires?
- Dual-certified: Our THHN&THWN-2 wires not only exceed UL standards, but also can be customized for CSA certification.
- Dual-rated: Our THHN/THWN-2 wires is dual-rated, so you don’t even have to choose.
- Global Reach: Available in AWG 14–4/0 sizes, color-coded for easy identification in international projects.
Conclusion
Whether your project demands THHN for controlled settings or THWN-2 for rugged applications, JZD Cable delivers dual rated and UL/CSA-certified reliability. Browse our certified wire portfolio or contact our experts for tailored solutions.
