C22.2 NO. 333-18

Preface This is the first edition of CAN/CSA-C22.2 No. 333, Electric motors for use in hazardous locations — Protection by maintaining the concentration of flammable fluids above the UFL (upper flammable limit). 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 This Standard applies to electric motors operating in flammable fluids that are maintained above the upper flammable limit (UFL), and the associated control systems to monitor and maintain the fluid concentration inside the motor above the UFL for use in hazardous locations in accordance with the Canadian Electrical Code, Part I. Notes: 1) This Standard is applicable for use only in industrial establishments with restricted public access, where the conditions of maintenance and supervision ensure that only qualified persons service the installation. 2) Motors can be used in a closed-loop such as in a refrigeration cycle or in an open line such as a natural gas pipeline. 1.2 This Standard is not applicable for use with material mixtures having a UFL greater than 90% (e.g., the UFL for acetylene is 99.9%). Note: Throughout this Standard, the UFL is expressed in terms of per cent by volume of the flammable fluid in the fluid volume in which the equipment is immersed. 1.3 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.