Preface
This is the fourth edition of CSA Standard C88, Power Transformers and Reactors. It supersedes the previous editions published in 1947, 1968, and 1979.
This revision of the Standard includes several significant changes including general reorganization and rearrangement. Major changes include the addition of external air clearances, the elimination of base MVA limits for induced, applied, and impulse tests, and the elimination of chopped wave tests. A requirement for measurements of apparent charge in addition to RIV measurements has been added for transformers over 245 kV. This Standard recognizes a transformer with forced directed oil flow and permits an average winding temperature rise of 70°C for these transformers. A requirement for thermally upgraded paper has been added. Clauses referring to prefault operating voltage and external short—circuit withstand requirements have been clarified.
This Standard was prepared by the Technical Committee on Power Transformers under the jurisdiction of the Standards Steering Committee on Electrical Engineering, and was formally approved by these Committees. It has been approved as a National Standard by the Standards Council of Canada.
Scope
1.1
This Standard, except as noted in Clause 1.2, applies to all liquid-filled transformers, auto transformers, booster transformers, load-tap-changing transformers, grounding transformers, phase-shifting transformers, series-voltage regulators, and shunt reactors.
Notes:
(1) The term transformer(s) in this Standard refers to the overall unit and not just to the electrical components implied by the definition.
(2) In general this Standard is written in reference to two winding transformers, although many requirements will be recognized to be common to multi winding transformers, auto transformers, load-tap-changing transformers, shunt reactors, and series-voltage regulators. Where there are special requirements for these (other) transformers, there are sections contained herein specifically addressed to them.
1.2
This Standard does not apply to the following:
(a) distribution transformers (CSA Standard C2, Single-Phase and Three-Phase Distribution Transformers, Types ONAN and LNAN);
(b) instrument transformers (CSA Standard C13, Instrument Transformers);
(c) dry-type transformers (CSA Standard C9, Dry-Type Transformers);
(d) pad-mounted transformers (CSA Standard C227 Series of Standards);
(e) submersible transformers (CSA Standard C301 Series of Standards);
(f) three-phase network transformers (CSA Standard C199, Three-Phase Network Transformers);
(g) rectifier transformers, welding transformers, furnace transformers, starting transformers, testing transformers, or current-limiting reactors.
Note: In the above list the pertinent CSA Standard number has been noted where such exists. Where no CSA Standard exists, this Standard may be used insofar as it applies.
