A tool used to determine the allowable number and size of conductors that can be installed in a specific size of electrical conduit, based on the National Electrical Code (NEC). It simplifies the complex calculations required to ensure compliance with safety standards. For example, one might use this tool to determine if seven #12 AWG THHN conductors can be safely installed in a 3/4″ EMT conduit.
Correctly calculating raceway capacity is essential for electrical system safety and performance. Overfilling raceways can lead to overheating of conductors, insulation breakdown, and potential fire hazards. Furthermore, exceeding the fill limits impedes the ability to pull conductors, increasing installation time and costs. Historically, electricians relied on manual calculations using tables and formulas within the NEC. This process was prone to error and time-consuming. Modern tools automate this process, ensuring accuracy and efficiency.