This recommended practice is for new substations and planned additions or improvements to existing substations. It is not intended that existing substations must be retrofitted to these recommended practices. For instruction on how to include this recommended practice in specifications, refer to 5.2. IEEE Std 693 is designed as an integrated set of requirements for the seismic qualification of electrical power equipment. Users should use IEEE Std 693 as a whole. Do not modify or remove any requirement,except as allowed herein.