IEEE 605-2023

This design guide provides direction for the substation engineer in the design of air insulated substations. This guide provides users with information on typical bus arrangements, including various criteria necessary to develop bus arrangement decisions. The guide is applicable to both rigid bus and strain bus designs for outdoor and indoor, air insulated, ac substations. This guide includes a method to calculate ampacity for electrical bus and ampacity tables for typical bus types and sizes. This guide also provides design criteria and a method to calculate electromechanical forces on insulators and bus resulting from gravity, wind, ice, short-circuit forces, and thermal expansion. This guide does not consider the following: a) The electrical criteria for the selection of insulators (see IEEE Std 1313.2™ [B41]) b) The seismic forces to which the substation may be subjected (see IEEE Std 693™ and IEEE Std 1527™) c) The design of mounting structures (see ASCE 113 [B8]) d) Design considerations for contaminated environments (see IEEE Std 1313.2 [B41]) e) Installation methods f) Design of direct current bus g) Fault loads other than between conductors such as in the presence of other magnetic fields (e.g., air core reactors)

Substation rigid and strain bus structure design involves electrical, mechanical, and structural considerations. It is the purpose of this guide to integrate these considerations into one document. Special considerations are given to fault current force calculations.

Revision Standard - Active. A proper design of the substation bus is aimed towards a safe and reliable operation of the substation and the power system. Two different types of buses are used in substations: the rigid bus and the strain (cable). Information is provided by this guide on the different bus arrangements used in substations stating the advantages and disadvantages of each. Information as related to each bus type and construction is also provided. Once the bus type is selected, the calculation tools for each bus type are provided by this guide. Based on these calculations, the bus size, forces acting on the bus structure, the number of mounting structures required, and hardware requirements can be specified by the engineer.