Scope 1.1 This Standard applies to: (a) heater elements for use in equipment that is intended to be connected to a supply of nominal system voltage of 600 V or less; and (b) those heater elements that are installed in accordance with the Rules of the Canadian Electrical Code, Part I. 1.2 This Standard applies to the following types of heater elements: a) open wire (including wire, ribbon, and expanded metal) b) metal sheathed (including removable-type range surface and grounded plug-in type) c) variable resistance/temperature (VR/T) and d) special (e.g., quartz tube, woven mat, parallel circuit mat, rope, cartridge, and strip). 1.3 This Standard does not apply to the following: a) heating cables b) electric duct heaters and c) uninsulated heater elements used in bare element water heaters. 1.4 In CSA standards, "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.