What is the ratio of voltage transformers VT) in Schneider recloser/ sectionaliser for measurement and protection functions?
Unlike traditional winding voltage transformer, Schneider reclosers/ sectionaliser utilise special voltage sensors for voltage measurement. They are called CVT (Capacitive Voltage Transformer) for N, U, W, RL series and RVD (Resistive Voltage Divider) for E series.
These sensors are molded in the epoxy bushings. Signals from these CVTs are modulated, digitalised before being converted through firmware algorithm into primary voltage reading and shown on controller panel.
Therefore there is no ratio which can be used to directly convert signals from CVT secondary circuits into primary voltage readings. Neither there is any access to secondary of CVTs or RVDs for users to measure so-called secondary signals or use them for a third party device.