Under continuous current conditions greater than specified values, how long does it take for the copper in a cable to fuse?

The fusing time for copper in a cable under continuous current conditions greater than specified values can vary depending on several factors, such as the gauge of the wire, the temperature rating of the insulation, and the specific current being applied.

When the current exceeds the safe limit for an extended period, heat generated by the electrical resistance of the copper can cause the material to reach its melting point, leading to a situation known as fusing. Typically, under these conditions, fusing occurs within a specified time frame that can be around 3 minutes.

This time allows for the buildup of sufficient heat to exceed the melting threshold of copper while considering factors such as heats capacity and the environment around the cable. Therefore, the answer aligns with commonly accepted electrical safety standards and guidelines regarding the performance of copper conductors under continuous overload conditions.