IEEE C37.95-2014 IEEE Guide for Protective Relaying of Utility-Consumer Interconnections.
4. Establishing consumer service requirements and supply methods 4.1 General design approach The supply that is selected should satisfy the consumer’s load requirements. Available utility supply options in the area as well as the utility s design standards and operation and maintenance practices should also be considered. 4.1.1 Consumer’s load requirements Prior to meeting with utility personnel, the consumer should define the present and future load requirements including the connected kVA, the average load, and peak demand power requirements (both real and reactive). The effect of interruptions and voltage dips on plant operation, the required dependability and security of the utility’ s electrical service, and any other needs that may be unique to the operation should be determined. The consumer’s engineer should be prepared to discuss these requirements in detail with utility engineers to ensure that there is a clear understanding of the consumer’s requirements. 4.1.2 Utility service availability The utility should describe the supply voltages available in the area and estimate the initial and total costs of the various alternatives. Most utilities establish nominal limits on the load that can be supplied at different voltage levels. The number of utility supply lines available and the performance level of each line should be discussed in detail. In addition, the utility should inform the consumer of any required studies, unusual problems, or future plans that may affect the quality or continuity of service. Some utilities publish standard information booklets detailing the requirements for service.
4.2.3 Future utility system changes The utility should inform the consumer of any substantial utility system changes. For example, the installation of a large transformer that alters short-circuit currents at the supply point may affect the consumer’ s power system or protection coordination. 4.3 Specific supply considerations In determining the final supply method, consideration should be given to the design of the interconnection, the arrangement of the utility’s supply system, its protective relaying requirements, and its maintenance requirements and responsibilities. 4.3.1 Division of ownership Individual operating and maintenance philosophies of the consumer and utility may impact electric system design. Regardless of ownership, however, the protective equipment should be specified and designed to provide a coordinated system. Proper engineering design must not be compromised, but the protection of the utility-consumer interconnection facilities should satisfy the objectives of both parties. In all cases, the protection requirements, equipment specifications, relay settings, fuse ratings, station battery requirements, and testing procedures should be discussed and agreed upon by both parties.
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