Calculate the Current Carrying Capacity of RADOX® Cables

Knowing the current carrying capacity of a cable is essential for selecting the right one for your application and for building safe, reliable electrical equipment without incurring unnecessary costs.
If you are using or considering adopting RADOX® cables (renowned for their performance in critical environments), this guide will help you correctly calculate the maximum allowable current and understand which parameters to monitor.

What is current carrying capacity calculation and why is it important?

Knowing the voltage or cross-section of a cable is not enough to determine how much current it can handle: a thermal calculation is required.

Every electrical conductor—no matter how efficient—dissipates part of the energy as heat. This phenomenon, known as the Joule effect, is related to the resistance of the cable and the current flowing through it. The formula is simple:

P = R x I²
(where R is the cable’s resistance and I is the current)

The higher the current, the hotter the cable gets.
To prevent temperatures from exceeding the safety limits set by standards, it is necessary to know exactly how much current can flow without damaging the insulating material or causing malfunctions.

HUBER+SUHNER Current Rating Tables

HUBER+SUHNER, creator and manufacturer of RADOX® cables, provides technical departments with official current rating calculation tables, which include:

• Indicative maximum current values for each cable cross-section;
• Reference temperatures;
• Correction factors for various operating conditions (bundle installation, ambient temperature, insulation type, etc.).

These tables are the most authoritative reference for making your own calculations and choosing the most suitable cable.

If you’d like to explore further, you’ll find all available RADOX® cables in our catalog at this link.