1.1 This standard recommends procedures and practices for the control of external corrosion on buried or submerged metallic components of residential electrical distribution systems, to be referred to in this standard as URD systems. This standard discusses the corrosion control factors that should be considered in designing components in URD systems, discusses the handling, storage, and installation practices of URD components to prevent damage that may permit corrosion to occur, stipulates the design, installation, operation, and maintenance of cathodic protection systems for submersible and direct buried transformers and equipment, and suggests a system of corrosion control records that will document data pertinent to corrosion control on URD systems.  1.2 This standard is intended to serve as a guide for establishing minimum requirements for control of corrosion on URD equipment.  1.3 This standard is intended for underground electrical distribution systems designed for residential service (see Figure 1). 1.4 The recommended practices given in this standard, including those for the design, installation, operation, and maintenance of cathodic protection systems, should be applied by or under the direction of a person qualified by experience and training in corrosion control methods.  1.5 This standard presents the basic considerations that should be given to prevent corrosion on URD equipment. Because of the complexities of environmental conditions in which URD equipment is buried, this standard does not designate all the detailed practices that may be required for specific applications.