The Siemens 3UG5625-2CW30 is a digital residual current monitoring relay designed for use with external current transformers (3UL23 series). It monitors leakage current in grounded AC systems and trips when the set threshold is exceeded, with independent ON and tripping delays adjustable from 0.1 to 999.9 seconds. The adjustment range covers 0.03 to 40 A, making it suitable for a wide variety of installation sizes — from sensitive equipment protection to main feeder monitoring. The universal supply voltage of 24 to 240 V AC/DC simplifies panel wiring across mixed-voltage control circuits.
RoHS compliance is effective from June 2023, and the product contains lead above the 0.1% threshold (CAS 7439-92-1) per REACH Article 33 — relevant for end-of-life reporting and waste handling in EU-regulated sites.
Integration Notes
The relay requires an external 3UL23 current transformer; verify the transformer window size fits the monitored conductor before mounting. Two changeover contacts (SPDT) provide independent alarm and trip outputs, or can be wired in series for fail-safe operation. The adjustable delays allow coordination with downstream protection devices to avoid nuisance tripping on transient leakage.