The Siemens 3RF3340-3AA45 is a 1-pole SIRIUS 3RF33 solid-state contactor rated for 40 A in AC-1 duty (resistive load) at a 40 °C ambient. The supply voltage range covers 48 to 600 V AC, and the control input accepts 4 to 30 V DC, making it compatible with standard 24 V DC PLC outputs or relay logic. The blocking voltage is 1200 V, giving headroom against line transients on a 480 V or 600 V system.
Deployment context: panel integration and wiring
The 3RF3340-3AA45 uses ring cable lug connection — expect to crimp ring terminals rather than push a wire into a cage clamp. That is common for higher-current solid-state contactors where the lug provides a vibration-resistant, high-contact-force termination. The package dimensions (105 x 27 x 122 mm) are sized for a standard DIN rail enclosure; the 27 mm width fits alongside a motor starter or a compact PLC in a control panel. No auxiliary contact block is built in, so if you need a feedback signal to the controller, plan for a separate interface relay or a stackable SIRIUS accessory.