33 Utilities
33.70.00 Electrical Utilities
33.71.00 Electrical Utility Transmission and Distribution 33.72.00 Utility Substations 33.73.00 Utility Transformers 33.74.00 Extra High Voltage (EHV) Switchgear and protection devices 33.75.00 High-Voltage Switchgear and Protection Devices 33.77.00 Medium-Voltage Utility Switchgear and Protection Devices 33.78.00 Substation Converter Stations 33.79.00 Site Grounding
