ABB 1SDA053681R1 is a SOR-C shunt release for SACE Tmax T breakers, frames T1, T2, T3. It trips on 110...127 V AC or 110...125 V DC. Active lifecycle status, no last-time-buy notice.
On the AC side, the lower bound of 110 V accommodates a sagging 120 V control bus under load; the 127 V ceiling covers a nominal 120 V +10 % tolerance. On the DC side, 110-125 V covers standard station battery ranges. The release is IEC-listed, which means it meets the performance and safety requirements of the International Electrotechnical Commission — the default standard for global panel builds outside North America (where UL 489 also applies, and the order code KT3S4 covers the UL/CSA variant).
This release mounts into the breaker's accessory slot on the Tmax T1, T2, or T3 frame — no additional DIN-rail space needed. The coil draws from the control circuit, not the main power path, so it's wired separately through the breaker's auxiliary terminal block. Verify the free-wheel diode polarity on the DC side before energizing; reversed polarity on a DC shunt release can weld the plunger.