Safety CTs can be installed in systems were lethal voltages are present. CTs should only be installed or maintained by competent individuals. After reviewing the risk for any particular installation all required precautions should be taken. CTs can produce high voltages on the secondary terminals if power is applied to the primary whilst they are… Read More »

Polarity Markings   Most Hobut CTs are labelled as per IEC61869-2 using the P1 – P2: S1 – S2 nomenclature, the table below gives cross reference to some common alternative terminal marking standards. Standard Primary Secondary IEC61869-2 P1 P2 S1 S2 IEEE C57.13 H1 H2 X1 X2 K L k l   CTs with multiple… Read More »

The diagrams below show the typical wiring schematic for various types of CT, Always follow the schematics and drawings issued for your particular installation Always observe the polarity of the device that the CT is wired to Measurement or Protection CT Only a single phase can be measured by each CT Core Balance or Earth… Read More »