Siemens 3WL1225-2CB31-1AA4-Z

The 3WL1225-2CB31-1AA4-Z is a fixed-mounted air circuit breaker from Siemens SENTRON 3WL series, frame size II, rated at 2500A and 690V AC for low voltage power distribution. This 3WL1225-2CB31-1AA4-Z is equipped with ETU electronic trip unit with adjustable LSI protection functions, covering overload, short-circuit instantaneous and short-time delay protection for transformers, main incoming feeders and bus tie circuits. The 3WL1225-2CB31-1AA4-Z adopts rear horizontal busbar connection layout and solid fixed mounting structure without withdrawable cradle.

This 3WL1225-2CB31-1AA4-Z supports optional communication modules for Modbus, enabling remote monitoring, power measurement and fault event upload to SCADA and energy management platforms. The 3WL1225-2CB31-1AA4-Z comes with spring stored-energy operating mechanism, supporting local manual operation and remote electrical closing and tripping. Built-in diagnostic functions record trip history and fault codes to accelerate troubleshooting after electrical faults. The suffix Z indicates custom optional accessories configured according to the original order specification.

The 3WL1225-2CB31-1AA4-Z is widely used as main incoming or bus coupler breaker in industrial substations, power plants, data centers and large commercial distribution switchboards. The SENTRON 3WL platform has been superseded by the newer 3WA series, and original production of this 3WL1225-2CB31-1AA4-Z is discontinued. Most available units are tested surplus spare parts for retrofit and emergency replacement of existing SIVACON low voltage panels.