Ring Type Current Transformers

Ring type ( or rectangular type ) CT are normally preferred over other types of CT. because they are simple in construction, mechanically stronger and cheaper. In a ring type bar primary type CT the working ampere-turns are determined by the primary current and therefore necessarily, the accuracy that can be offered with these CT becomes progressively inferior as the rated primary current decreases.'-If higher accuracy and burdens are required for CT of low primary current wound types CT are used.