Under continuous current conditions greater than specified values, how long does it take for cable jackets to melt?

The duration it takes for cable jackets to melt under continuous current conditions greater than specified values can often be cited around 1 minute. This timeframe aligns with standard assessments of cable performance under overload conditions, where thermal effects become significant. When cables carry current beyond their rated capacity, they generate excess heat due to resistance. The materials used for cable jackets, typically made from plastics or other thermosetting compounds, have specific thermal thresholds.

In many practical scenarios, prolonged exposure to temperatures exceeding these limits will lead to a rapid degradation of the jacket material, with melting generally occurring around the one-minute mark in situations of continuous overload. Understanding this is crucial for safety and maintenance practices in electrical installations.