Solid-state contactor for resistive loads
The Siemens 3RF3320-1AA65 is a 1-pole SIRIUS 3RF33 solid-state contactor rated for 20 A in AC-1 duty at 40 °C, with a blocking voltage of 1200 V and a control supply of 110 V DC. The AC-1 rating means it is sized for resistive loads — heaters, ovens, lighting banks — where the current waveform is sinusoidal and inrush is minimal. For motor or transformer loads (AC-3 or AC-4 duty), the same physical contactor must be derated; the 20 A AC-1 figure is the maximum continuous current the semiconductor junction can sustain under resistive switching.
The screw-terminal design suits panel wiring where ring or fork terminals are preferred over spring-cage. The 48-600 V operating range covers standard three-phase line voltages across global installations. The 110 V DC coil is common in North American control circuits; verify the control transformer secondary matches before wiring.