Calculations of power cable load capability on a desktop computer: a review

This paper describes a user oriented computer program for power cable load capability (ampacity) calculations developed in Ontario Hydro. The program is based on the IEC Standard, Publication 287 and Neher-McGrath procedure and is implemented in a user friendly form for desktop computer. Power cable load capabilities for a wide range of conditions can be calculated with a minimum of input data using this program aimed at regular as well as casual users. The program is further enhanced by its ability to retain reference files of previous calculations and compare alternative solutions. The initial library of 47 distribution cables, included in the database, eliminates the need for time consuming input procedures. The computerised algorithms of the program also contain further enhancements to the IEC method which allow it to deal effectively with the special nature of modern distribution cables. The program has been presented and demonstrated to Canadian utilities and power cable manufacturers in several seminars sponsored by the Canadian Electrical Association (CEA) and has had a very favourable reception. An application of the program for ampacity calculations of six cables in a duct bank is shown as an illustration.