How to size conduit for cable

Calculating conduit fill is an essential part of any large-scale electrical installation – Essentra Components offers a guide to assist installers, accessible free HERE.

The Essentra Components guide explains that conduit fill, also known as raceway fill, is the amount of a conduit’s cross-sectional area occupied, or filled, by a cable or multiple cables. The fill is based on the cable outside diameter (O.D.) and the conduit inside diameter (I.D.).

Determining cable conduit fill is said to be critical in order to comply with the requirements of the National Electrical Code (NEC). 

Failing to do this correctly it is stated can lead to expensive and time-consuming rewiring at the very least, and at most, an electrical installation that’s dangerous.

Other important factors to consider for a safety and best practice include conduit material choice, conduit size, calculating a cross section and more, all covered in the guide.