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 The transformer consists of primary and secondary coils that are wound upon a core, the assembly being enclosed in a waterproof case. The primary coil is connected into the series circuit and the secondary coil to the light fixture lead, by means of plug/receptacle connectors. The receptacle portion of the connector is provided with the transfomer to mate with the plug portion on the series circuit and light fixture cables. The transformer receptacle portion may be either built into the transformer body or moulded into the ends of transfomer leads. 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.