33.71.00 Electrical Utility Transmission and Distribution
33.71.19.13 Electrical Manholes and Handholes
33.71.13 Electrical Utility Towers 33.71.13.13 Precast Concrete Electrical Utility Towers 33.71.13.23 Steel Electrical Utility Towers 33.71.13.33 Wood Electrical Utility Towers 33.71.16 Electrical Poles 33.71.16.13 Precast Concrete Electrical Utility Poles 33.71.16.23 Steel Electrical Utility Poles 33.71.16.33 Wood Electrical Utility Poles 33.71.19 Electrical Underground Ducts, Ductbanks,And Manholes 33.71.19.13 Electrical Manholes and Handholes 33.71.19.23 Trenched Electrical Underground Duct and Ductbanks 33.71.19.33 Trenchless Electrical Underground Duct and Ductbanks 33.71.23 Insulators and Fittings 33.71.23.13 Suspension Insulators 33.71.23.16 Post Insulators 33.71.23.23 Potheads 33.71.26 Transmission and Distribution Equipment 33.71.26.13 Capacitor Banks 33.71.26.16 Coupling Capacitors 33.71.26.23 Current Transformers 33.71.26.26 Potential Transformers 33.71.36 Extra-High-Voltage Transmission Wiring 33.71.36.13 Overhead Extra-High-Voltage Transmission Wiring 33.71.39 High-Voltage Transmission Wiring 33.71.39.13 Overhead High-Voltage Transmission Wiring 33.71.39.23 Underground High-Voltage Transmission Wiring 33.71.39.33 Underwater High-Voltage Transmission Wiring 33.71.49 Medium-Voltage Transmission Wiring 33.71.49.13 Overhead Medium-Voltage Transmission Wiring 33.71.49.23 Underground Medium-Voltage Transmission Wiring 33.71.49.33 Underwater Medium-Voltage Transmission Wiring 33.71.53 Direct-Current Transmission 33.71.73 Electrical Utility Services 33.71.83 Transmission and Distribution Specialties