What is the minimum length of conductor that must be left in a box for making connections?

In electrical installations, it is crucial to leave sufficient length of conductor within boxes to ensure safe and accessible connections. The minimum length of 150mm (6 inches) is stipulated in the electrical code to provide enough wire for making connections without straining or damaging the conductors. This length allows electricians to effectively work with the wires, facilitating twists, splices, or terminal connections, while also considering factors like wire tension and termination methods.

Leaving conductors that are too short can hinder secure connections and might lead to issues such as pull-outs, overheating, or the inability to make necessary adjustments during installation or maintenance. Therefore, adhering to the requirement of 150mm ensures not only compliance with safety standards but also longevity and reliability in electrical systems.