Eaton NSB C311CT4 Split Core Current Transformer

The Eaton NSB C311CT4 Split Core Current Transformer is a clamp-on sensing device that encircles a conductor to monitor current without disconnecting wiring. It provides a 500:1 A transformation ratio, delivering a 1 A secondary output for every 500 A of primary current. Its split-core construction enables installation around an existing conductor, making retrofits quick in panels or switchgear. This model is part of Eaton’s NSB current transformer family and is identified by the C311CT4 designation, offering a compact, non-invasive solution for current sensing in electrical installations. In operation, the transformer converts the measured primary current into a safe, standardized secondary current suitable for metering, monitoring, or protective relays that accept a 1 A input. The combination of a split-core design with a high primary current ratio makes it suitable for retrofits and retrofit monitoring projects where minimizing downtime is important.