Preface This is the ninth edition of CSA C22.2 No. 46, Electric air heaters, one of a series of Standards issued by CSA Group under Part II of the Canadian Electrical Code. It supersedes previous editions published in 1988, 1981, 1980, 1971, 1966, 1959, 1942, and 1938. This edition mainly serves to incorporate Updates 1 through 4 of the 1988 edition, modify the scope to clarify the products not covered by this Standard, and to update the reference publications. For general information on the Standards of the Canadian Electrical Code, Part II, see the preface of CAN/CSA-C22.2 No. 0. This Standard is considered suitable for use for conformity assessment within the stated scope of the Standard. Scope 1.1 This Standard applies to air heaters intended for use on nominal system voltages of 600 V or less and designed to be used in accordance with the Canadian Electrical Code, Part I. 1.2 This Standard applies to permanently connected and cord-connected air heaters for household, commercial, and industrial use in non-hazardous locations. 1.3 The term "air heater" includes the following types: (a) convection; (b) forced air; (c) radiation; (d) ceiling types, alone or in combination with lighting or ventilating components, or both; (e) liquid-filled radiator; and (f) combinations of (a), (b), or (c). Note: For convenience, except where distinctions are necessary, portable and stationary air heaters are referred to throughout this Standard as "heaters". 1.4 This Standard does not apply to (a) unit heaters involving only steam or hot-water heating with an electric air circulator; (b) electric duct heaters, as covered in CSA C22.2 No. 155; (c) central electric warm-air furnaces, as covered in CSA C22.2 No. 236; and (d) radiant space-heating panels    (i) installed below the subfloor;    (ii) mounted behind drywall or above plaster ceilings;    (iii) mounted above a suspended ceiling grid system;    (iv) forming all or part of a finished ceiling system; and    (v) dropped into a ceiling system in its final finished form. Requirements for cord-connected double-insulated electric air heaters are specified in Clause 8 of this Standard. 1.5 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 (nonmandatory) to define their application.