CSA Group CAN/CSA-C802.2-18 Test method and minimum efficiency values for dry-type transformers

Preface

This is the fourth edition of CAN/CSA-C802.2, Test method and minimum efficiency values for dry-type
transformers. It supersedes the previous editions published in 2012, 2006, and 2000 under the title
Minimum efficiency values for dry-type transformers.

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 Dry-Type 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.

CSA Group acknowledges that the development of this Standard was made possible in part by the
financial support of Natural Resources Canada (NRCan), Canadian Electricity Association (CEA),
Independent Electricity System Operator (IESO), and SaskPower.

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.
Notes:
1) Use of the singular does not exclude the plural (and vice versa) when the sense allows.
2) Although the intended primary application of this Standard is stated in its Scope, it is important to note that it
remains the responsibility of the users of the Standard to judge its suitability for their particular purpose.
3) This Standard was developed by consensus, which is defined by CSA Policy governing standardization — Code
of good practice for standardization as “substantial agreement. Consensus implies much more than a simple
majority, but not necessarily unanimity”. It is consistent with this definition that a member may be included in
the Technical Committee list and yet not be in full agreement with all clauses of this Standard.
4) To submit a request for interpretation of this Standard, please send the following information to
[email protected] and include “Request for interpretation” in the subject line:
a) define the problem, making reference to the specific clause, and, where appropriate, include an
illustrative sketch;
b) provide an explanation of circumstances surrounding the actual field condition; and
c) where possible, phrase the request in such a way that a specific “yes” or “no” answer will address the
issue.
Committee interpretations are processed in accordance with the CSA Directives and guidelines governing
standardization and are available on the Current Standards Activities page at
standardsactivities.csagroup.org.
5) This Standard is subject to review within five years from the date of publication. Suggestions for its
improvement will be referred to the appropriate committee. To submit a proposal for change, please send the
following information to [email protected] and include “Proposal for change” in the subject line:
a) Standard designation (number);
b) relevant clause, table, and/or figure number;
c) wording of the proposed change; and
d) rationale for the change.

1 Scope

1.1
This Standard specifies efficiency values for dry-type transformers. The total ownership cost (TOC)
methodology is recommended as the means for achieving these efficiencies, particularly for electric
utilities. This Standard also specifies an optimal method for users other than utilities, based on a
modified TOC methodology that meets the conditions of energy cost.
Note: See Table 1 for minimum efficiency values.

1.2
This Standard covers single-phase and three-phase self-contained units or components of larger
assemblies, nominal frequency of 60 Hz, having a high-voltage winding of 35 kV or less, ANN, rated
15 to 833 kVA for single-phase and 15 to 7500 kVA for three-phase.

1.3
This Standard describes the special features that influence efficiency and provides modifications to the
efficiency values specified in Table 1 where such modifications are necessary.

1.4
This Standard specifies the test methods and procedures for determining transformer efficiencies.

1.5
This Standard does not apply to
a) autotransformers;
b) grounding transformers;
c) rectifier transformers;
d) sealed transformers;
e) non-ventilated transformers (including encapsulated transformers);
f) testing transformers;
g) furnace transformers;
h) welding transformers;
i) drive (isolation) transformers with two or more output windings or a rated low-voltage line current
greater than 1500 A;
j) special impedance transformers;
k) transformers with a nominal low-voltage line current of 4000 A or more;
l) on-load regulating transformers;
m) resistance grounding transformers;
n) transformers with two or more independent secondary windings for more than one independent
output voltage for main power transformation. Any independent windings used to provide either
single-phase or three–phase power to auxiliary devices are not included in the count of the
CAN/CSA-C802.2-18 Test method and minimum efficiency values for dry-type transformers
October 2018 © 2018 Canadian Standards Association 8
number of independent windings when determining the type of transformer, and are completely
excluded from the kVA rating, testing, and calculations for energy efficiency purposes. Secondary
windings designed to be reconfigured in either series or parallel in order to provide two different
voltages are not considered independent windings.
o) transformers with a low-voltage winding BIL above 30 kV; and
p) transformers that are in a voltage class greater than 1.2 kV and that have a BIL of less than 20 kV
or more than 199 kV.

1.6
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.