3PH 277 480 CT PT cabinet 201 to 1201amp.pdf

This is an Instrument Transformer installation service manual document from Ameren Illinois providing technical specifications for CT/PT rated meter installation at 600 volts, 480Y/277 volts, three-phase, four-wire service for electric systems rated between 201 and 1200 amperes. The document outlines construction requirements and installation guidelines for current transformer (CT) and potential transformer (PT) equipment positioning, including mandatory placement heights of 36 inches minimum to 66 inches maximum above final grade. The specifications require bar-type CTs, galvanized steel or aluminum rigid metal conduit (RMC), EMT, or Schedule 40 piping, with neutral conductor termination along the enclosure side and ground-level conduit runs of minimum 24 inches if duct-run or 30 inches if direct-buried cable. A warning label indicating that meter removal does not de-energize service must be affixed to the CT enclosure lid, and 480-volt stickers are required. Indoor CT installations require prior approval from both the Field Metering Supervisor and Field Supervising Engineer.

This technical document directly supports the EV Charging Station Installation project at the Microtel Inn by Wyndham in Champaign, Illinois, which requires substantial electrical infrastructure including a 750kVA utility transformer, 1200A main switchboard, and CT/PT metering cabinet to support four Tesla V4 Superchargers with 625kVA power cabinet specifications operating at 480V AC input. The project requires coordination with Ameren Illinois utility services, Illinois electrical licensure, and EVITP certification for installation personnel, with completion of civil work, signage, permits, inspections, and all regulatory approvals.