Preface 

This is the third edition of CSA C802.1, Minimum efficiency values for liquid-filled distribution transformers. It supersedes the previous editions published in 2013 and 2000. Major changes to this edition include the following: a) The minimum individual values of efficiency in Table 1 have been calculated to reflect the minimum average values required by 10 CFR 431 efficiency values. b) A range of impedance has been added to Table 1. c) An explanation as to how harmonization has been achieved is given in Annex A. CSA Group acknowledges that the development of this Standard was made possible, in part, by the financial support of BC Hydro, Hydro Québec, Electricity Canada, Fortis BC Electric, and Natural Resources Canada. This Standard is considered suitable for use for conformity assessment within the stated scope of the standard. This Standard was prepared by the Subcommittee on Liquid-Filled Distribution Transformer Efficiency, under the jurisdiction of the Technical Committee on Industrial Equipment and the Strategic Steering Committee on Performance, Energy Efficiency, and Renewables, and has been formally approved by the Technical Committee. This Standard has been approved as a National Standard of Canada by the Standards Council of Canada. This Standard has been developed in compliance with Standards Council of Canada requirements for National Standards of Canada. It has been published as a National Standard of Canada by CSA Group. 

Scope 

1.1 General 

This Standard specifies energy efficiencies for liquid-filled distribution transformers. The total ownership cost (TOC) methodology is recommended as the means for achieving these energy efficiencies, particularly for use by electric utilities. This Standard also specifies an optimal method for non-utility users, based on a modified TOC methodology that meets the conditions of energy cost. 

1.2 Application 

The transformers to which this Standard applies are single-phase and three-phase, 60 Hz, liquid-filled distribution transformers, rated at 10 to 833 kVA for single-phase and at 15 to 3000 kVA for three- phase, insulation class 34.5 kV and less, and low-voltage windings of 600 V or less. 

1.3 Efficiency modification 

This Standard describes special features that influence efficiency, and provides for the necessary modifications to the tabulated efficiency values. 

1.4 Content 

This Standard addresses the test methods and procedures for determining the transformer efficiencies. 

1.5 Exclusions 

This Standard does not apply to a) autotransformers; b) testing transformers; c) welding transformers; d) furnace transformers; e) rectifier transformers; f) network transformers; g) grounding transformers; h) a transformer with a nominal low-voltage winding line current of 4000 A or more at base kVA; i) special impedance transformers; j) transformers with special core/coil designs required by dimensional constraints; k) transformers with tap ranges greater than 20%; l) transformers with frequencies other than 60 Hz; or m) step-voltage regulators. 

1.6 Terminology 

In this Standard, "shall" is used to express a requirement, i.e., a provision that the user is obliged to satisfy in order to comply with the Standard; "should" is used to express a recommendation or that which is advised but not required; and "may" is used to express an option or that which is permissible within the limits of the Standard. Notes accompanying clauses do not include requirements or alternative requirements; the purpose of a note accompanying a clause is to separate from the text explanatory or informative material. Notes to tables and figures are considered part of the table or figure and may be written as requirements. Annexes are designated normative (mandatory) or informative (non-mandatory) to define their application.