3-Phase SSR for Heater Control
The Omron G3PE-545B-2N is a 3-phase solid state relay designed specifically for heater control, rated at 45 A load current at 40 °C and capable of switching loads up to 37.4 kW at 480 VAC. The output handles line voltages from 200 to 480 VAC (operating range 180 to 528 VAC), making it a direct fit for standard 3-phase heater banks in injection molding barrel zones, packaging seal bars, or industrial ovens. The zero-cross function (equipped) turns on near the voltage zero point, which minimizes inrush current and reduces electrical noise — a practical advantage when the SSR is switching resistive heater loads where clean switching extends heater life and cuts harmonic injection into the line. Input side accepts a 12 to 24 VDC control signal (operating range 9.6 to 30 VDC) with a maximum draw of 10 mA at 24 VDC. The release voltage is 1 VDC minimum, so the relay drops out cleanly when the control signal falls below that threshold. Isolation is via phototriac, which provides galvanic separation between the low-voltage PLC or temperature controller output and the power circuit.
Duty Cycle and Inrush Handling
The SSR is rated for inrush current resistivity of 440 A (60 Hz, 1 cycle) and a permissible I²t of 1260 A²s. This matters when the heater elements are cold — tungsten or ceramic heaters draw a brief surge on startup. The G3PE-545B-2N can absorb that surge without weld-failure of the output triac. Minimum load current is 0.5 A, so it will not drop out on lightly loaded phases. Screw terminals simplify panel wiring; no special crimp tooling needed.