Preface:

This is the second edition of CSA C22.2 No. 0.2, Insulation coordination, one of a series of Standards issued by CSA Group under Part II of the Canadian Electrical Code. It supersedes the previous edition published in 1993.

The requirements of this Standard are intended to harmonize with the IEC 60664 series, Insulation coordination for equipment within low-voltage systems.

The IEC database provides clearance values, which can be used for product evaluation, that were developed based on particular overvoltages and inhomogenous fields. The object of this Standard is to guide Technical Committees in the development of alternative requirements and to establish a common basis to address clearance and creepage distances when the concept of insulation coordination is employed. This Standard provides information necessary to give guidance to Technical Committees when specifying clearances in air, creepage distances, and solid insulation for equipment in which the concept of insulation coordination is used.

Scope:

1.1
This Standard uses principles of insulation coordination in specifying through-air and over-surface spacing requirements for electrical equipment used in accordance with the Rules of the Canadian Electrical Code, Part I.

1.2
The complete principles of insulation coordination involve consideration of a combination of clearances, creepage distances, and properties of solid insulation used to constitute an insulation system. This Standard includes considerations for clearances and creepage distances.
Note: The empirical data gathered thus far have been used to develop requirements for clearances and creepage distances as presented in this Standard. Data required to develop an evaluation procedure for solid insulation are still being compiled. When available, this evaluation procedure will be added to this Standard. It is anticipated that the evaluation procedure will not affect the requirements for clearances and creepage distances.

1.3
These requirements are intended to be used only where specifically referenced by other Standards of the Canadian Electrical Code, Part II.
Note: These requirements may be used as an alternative to required spacings when referenced by an end-product standard.

1.4
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.