Siemens 3UA12 Relay

Siemens 3UA12 thermal overload relay (model 3UA1202) provides motor protection by monitoring main-circuit current and tripping when the load exceeds its 16–32 A rating. The device supports a maximum operating voltage of 500 V, making it suitable for standard industrial motor circuits up to that voltage. Part of the Siemens 3UA overload relay family, the 3UA12 variant is identified by the 3UA1202 code and is designed for integration in panel-mounted motor protection schemes alongside compatible Siemens equipment. In practical terms, it protects motors from overload and overheating in applications such as pumps, fans, conveyors, and compressors by interrupting the circuit when current draw is too high. When selecting this relay, confirm that the motor’s full-load current lies within the 16–32 A range and that the system voltage aligns with the relay’s 500 V maximum. The compact form factor and Siemens engineering support typical HVAC, process, and manufacturing environments where reliable thermal protection is required.