Instrument transformer ASB series

currentencapsulatedlow-voltage

Mainly are used where it is imposible or difficult to measure currents directly. They are special configurations of transformers which transform the primary current into a (mostly) lower secondary current and which separete (galvanicaly) both circuits. By means of the physical principle of saturation of the core material additional a protection of the secondary circuit from high currents produced in the event of system fault is enable. Generally current transformers are distinguished for measuring purpose and protection purposes. Instrument transformers are assigned for connection direct reading, writing and counting measuring equipment and protecting these additional from overcurrent. Protection transformers are assigned for connecting plants protection equipment. Fundamentally can be distinguished between single conductor current trasformers and wound primary current transformers. The most important type of single conductor CTs is the window type CT which is designed to be pushed onto the primary conductor. Together with this conductor a special transformer with one primary turn is built. The power performance of a current transformer depends on the transformation atio and on the cross-section of the iron core. If the primary current is too low a single conductor CT with a higher transmission is to be used. To simulate the higher current (corresponding to the higher transmission) the primary conductor is put through the single conductor CT for a several times. In this way a wound primary current transformer is constructed.