Here at FDB Electrical we have a wide range of core-balance transformers (CTs) for use in monitoring supply conductors together with with earth leakage relays (ELRs and ELCBs) and MCCBs where the CT provides a warning signal from the incoming cable, giving advance information to the trip device so ensuring greater safety for personnel and equipment.
We have these available from our online store from 16mm up to 240mm to accommodate most cable sizes.