Full Description

Preface

This is the third edition of CSA C747, Energy efficiency test methods for small motors. It supersedes the previous edition published in 2009 and the 1994 Standard published under the title Energy Efficiency Test Methods for Single- and Three-Phase Small Motors. Changes in this edition include a) revision of scope to not limit the minimum rating (only stating a maximum); b) revision of the definition for thermal equilibrium; c) inclusion of frequency uncertainties; d) revision to air-over motor temperature measurement method; e) determining average full-load and nominal efficiency was added; and f) energy efficiency levels and tables were added. CSA Group acknowledges that the development of this Standard was made possible, in part, by the financial support of BC Hydro, Efficiency Manitoba, independent Electrical System Operator, Natural Resources Canada, and Northwest Energy Efficiency Alliance. 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 Small Motors, 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 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 Inclusions This Standard specifies the test methods to be used in measuring the energy efficiency of small direct- current (dc), and single- and small three-phase alternating-current (ac) motors. It includes the following motor types: a) capacitor, permanent-split; b) capacitor, capacitor-start or capacitor-run; c) split phase; d) split phase start, capacitor-run; e) shaded pole; f) reluctance*; g) polyphase induction; h) dc*; i) permanent magnet*; j) brushless dc*; k) converter driven*; and l) other single-phase motors suitable for output input test method.* * Where a motor requires a converter to operate on alternating current supply, the motor and converter are tested together.

1.2 Application This Standard applies to a) dc and three-phase ac motors with rated output power less than or equal to 0.746 kW; and b) single-phase ac motors of the type specified in Clause 1.1.

1.3 Marking and tolerance This Standard specifies marking methods and allowable tolerances on energy efficiency values.

1.4 Continuous duty This Standard applies only to motors rated for continuous duty.

1.5 SI units SI units of measurement should be used in the application of this Standard; however, other units may be used for testing provided that they are used consistently.

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.