CSA C22.2 No. 180:25

1 Scope 1.1 This Standard applies to encapsulated isolating transformers for use as a circuit continuity device, intended to be installed in airport field lighting series circuits for use in nonhazardous locations in accordance with the Canadian Electrical Code, Part I. 1.2 This Standard applies to transformers that consist of electrically separated primary and secondary coils that are wound upon a core, the assembly being enclosed in a waterproof case with moulded-on lead connectors. The primary coil is connected into the series circuit and the secondary coil to the light fixture lead by means of plug/receptacle connectors. 1.3 Transformers constructed to meet the requirements of this Standard are suitable for continuous outdoor service in ambient temperatures from a minimum of –55 °C to a maximum of 65 °C and for direct earth burial or placement in a housing (junction box) of an airport lighting raceway system. 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.