Abstract: A waterproof current transformer for supplying current to electrical cable monitoring devices includes a core assembly for attaching a remote circuit module to a monitored conductor and provides a concentrated magnetic flux indicative of the current level in the conductor. To facilitate installation and removal of the current transformer from the conductor, the core assembly is formed by a plurality of laminations served together and arranged in a generally rectangular configuration and joined with a magnetically conductive interlocking connecting means. A means for resisting moisture is disposed about the transformer to enable an indefinite submersion time span.