ETAP calculates cable ampacity based on NEC and ICEA P.54-440 methods for U/G duct banks, U/G direct buried, A/G cable trays, A/G conduits, and air drops. The process is systematic and simple. For example, for A/G trays, simply enter the tray height, width, and percent fill, ETAP calculates the derated ampacity based on user specified ambient and conductor operating temperatures. For duct banks, specify the number of rows, columns, ambient temperature, and soil thermals resistivity, ETAP calculates the derated ampacity based on the hottest location not exceeding the maximum operating temperature. ETAP also calculates the current carrying capacity of cables under various cable installations and operating conditions based on the following standards:

ETAP provides optimal and alternative cable sizes based on voltage drop and load current requirements. Load current can be based on the full-load amp of any element on the one-line diagram or as a user-specified value. You can size cables (motor feeders, transformer cables, etc.) instantly based on the cable derated ampacity for any type of installation (direct banks, trays, conduit in air, etc.).

ETAP Cable Sizing provides various options which can be used as design requirements. These design requirements can be user-defined or automatically determined from load flow, short circuit, and protective device calculation results.