CTSCMWH120/0.333V Split Core Circuit Transformer 120A Input, 333 mV Output. A range of mV split core current transformers are designed to fit into confined spaces while the primary conductor is still live. The current transformers are made in a compact design with a mechanical hinge for multiples opening and closing action. For connection into existing networks, they are often for use with multi function meters that have 0.333 V input.