The IEEE 693: Recommended Practice for Seismic Design of Substations. [1] is a Institute of Electrical and Electronics Engineers standard. This standard is recognized also by American National Standards Institute, and is used mainly in the American Continent. [2]
The goal of the standard is to provide a single set of rules and regulations that cover the seismic design of both new and existing electrical substations, hence leading to standardization. [3] The standard provides the minimum requirements that the design of an electrical substation (except nuclear power plants) must adhere to. The norm includes the design of circuit breakers, transformers, disconnect and grounding switches, instrument transformers, circuit switches, surge arresters, and other equipment. [4]
The norm contains the 8 chapters named below: [5]
The norm specifies 3 seismic qualification levels (high, medium, low). [6] The Zero Period Acceleration (ZPA) (a.k.a. Peak Ground Acceleration) for the high and the medium qualifications levels are set to be 0.5g and 0.25 respectively (no calculation is required for equipment with "low" qualification), where g stands for acceleration due to gravity. The Peak Acceleration (i.e. the peak of the Response Spectrum) at 2% damping is lower than 1.65g and 0.85g for high and medium qualification respectively, with the cutoff frequency defined as 33Hz. [3]
The qualification is allowed through one of the following: [7]
The norm suggests that most equipment in the same area be given the same qualification level (for interchangeability and redundancy).
There are a total of 22 annexes in the standard, 19 of which are normative, and the other 3 are informative. [5]
The first version of the standard was released in 1997, with a revised version released in 2005 and later in 2018. [9]
The IEEE 693: Recommended Practice for Seismic Design of Substations. [1] is a Institute of Electrical and Electronics Engineers standard. This standard is recognized also by American National Standards Institute, and is used mainly in the American Continent. [2]
The goal of the standard is to provide a single set of rules and regulations that cover the seismic design of both new and existing electrical substations, hence leading to standardization. [3] The standard provides the minimum requirements that the design of an electrical substation (except nuclear power plants) must adhere to. The norm includes the design of circuit breakers, transformers, disconnect and grounding switches, instrument transformers, circuit switches, surge arresters, and other equipment. [4]
The norm contains the 8 chapters named below: [5]
The norm specifies 3 seismic qualification levels (high, medium, low). [6] The Zero Period Acceleration (ZPA) (a.k.a. Peak Ground Acceleration) for the high and the medium qualifications levels are set to be 0.5g and 0.25 respectively (no calculation is required for equipment with "low" qualification), where g stands for acceleration due to gravity. The Peak Acceleration (i.e. the peak of the Response Spectrum) at 2% damping is lower than 1.65g and 0.85g for high and medium qualification respectively, with the cutoff frequency defined as 33Hz. [3]
The qualification is allowed through one of the following: [7]
The norm suggests that most equipment in the same area be given the same qualification level (for interchangeability and redundancy).
There are a total of 22 annexes in the standard, 19 of which are normative, and the other 3 are informative. [5]
The first version of the standard was released in 1997, with a revised version released in 2005 and later in 2018. [9]