Outdoor Oil Immersed CT Pt Combined Metering Unit

Current and potential transformers are usually used as single phase units. However nowadays, combined ct-pt units are the most commonly used variant of current and potential transformers, especially while being used for metering purposes for single or multiple ratios. At times, an additional core is provided too for protection purpose.
The combined ct-pt units is used for - 3 phase 3 wire metering system or for 3 phase 4 wire metering system. In case of combined ct-pt units we use a single unit consisting of 23 single phase cts and one 3 phase pt in place of 23 single phase cts and 3 single phase pts.