What size should electrical conduit be in relation to the maximum diameter of a cable bundle?

When selecting the size of electrical conduit in relation to the maximum diameter of a cable bundle, it is crucial to ensure that the conduit provides enough space for the cables while allowing for proper installation and heat dissipation. The guideline to use a conduit that is 25% larger than the maximum diameter of the cable bundle is based on the National Electrical Code (NEC) and industry best practices.

Choosing a conduit that is larger than the maximum diameter ensures that there is sufficient room for the cables to be installed without excessive bending or pinching, which could damage the cables or impede their performance. Additionally, the extra space helps in minimizing the risk of overheating, as cables generate heat during operation and need adequate ventilation.

This practice adds a margin for error in case the cables have irregular shapes, or if there may be variations in the size of the cables being used. Therefore, selecting a conduit that is 25% larger than the maximum diameter effectively promotes safety, functionality, and compliance with regulatory standards in electrical installations.