⚡ Smart Solar Wiring Starts with Smarter Temperature Design.

⚡ Smart Solar Wiring Starts with Smarter Temperature Design

Why Designing for 55°C Conductor Temperature Protects Your System—and Your Switchgear

In Gauteng’s intense summer heat, solar systems face more than just load stress—they face thermal stress. Many installations still rely on older copper cables rated for 70°C, and even newer 90°C-rated cables can cause excessive heating in switchgear when not properly derated.

🔍 Real-World Scenario

• Cable: 25 mm² insulated copper

• Ambient Temperature: 30°C

• Current: 100 A continuous

• Temperature Rise: ~40°C

• Conductor Temperature: ~70°C

This setup is already at the maximum safe limit for older cables. But what happens when ambient temperature rises?

🌡️ At 40°C Ambient

• Conductor temp = 40°C + 40°C rise = 80°C

• That’s too hot for 70°C-rated cables

• Even 90°C-rated cables can overheat switchgear terminals, causing:

  • 🔥 Terminal damage

  • ⚠️ Breaker malfunction

  • 💡 Insulation degradation

📉 Safer Design: Target 55°C Conductor Temperature

To protect both cables and switchgear, we recommend designing for a maximum conductor temperature of 55°C. This gives a 15°C safety buffer, especially in:

• 🔌 Enclosed DBs

• ☀️ Rooftop conduits

• 🔧 Older reticulation networks

✅ Best Practices for Installers & Engineers

• Use XLPE or higher-rated insulation, but design conservatively

• Apply temperature correction factors during cable sizing

• Avoid tight enclosures or direct sun exposure without ventilation

• Use thermal imaging during commissioning

• Educate clients on the long-term risks of thermal creep

💬 Why It Matters

Designing for 55°C isn’t just conservative—it’s covenantally responsible. It reflects a commitment to systems that endure, protect, and serve faithfully.

📍 Serving Johannesburg & surrounds | 🌐 [www.alwaysonenergy.co.za]📞 0824442347] ✉️ [cobus@alwaysonenergy.co.za]