The SECAP-25 is a DIRECTIONAL earth fault relay with a Ø25 mm summation transformer built into the unit, intended for IT (isolated-neutral) networks. Direction is the point of it. In an IT system every feeder is galvanically connected to every other one and the whole network shares its capacitive leakage to earth, so an ordinary earth-leakage relay watching one feeder also registers faults that belong to somebody else's circuit and raises an alarm nobody can act on. A directional relay resolves which side of itself a fault lies on and responds only to faults within its own installation, which is what makes the alarm mean something and what makes it possible to find the fault instead of merely knowing the network has one. It provides a potential-free normally-open alarm contact and a 12 V output for remote annunciation, which drives the CU-12 indicator panel. This is the J variant: ADJUSTABLE sensitivity from 30 to 300 mA with a 1 second delay, supplied WITHOUT the CU-12 indicator panel. The adjustable setting is what allows the relay to be lifted above an installation's standing capacitive leakage — the usual cause of an earth fault alarm that cannot be cleared because nothing is actually wrong — while still detecting a genuine insulation failure. For local indication, order the CU-12 alongside it or specify the SECAP25JP, which is the same relay supplied with the panel. Manufactured in Spain and supplied under the Function brand. Supplied by cBallast on quote-to-invoice terms; lead time and freight are quoted per RFQ against the destination Incoterm.