SIRIUS Size S2 Power Contactor — 65 A at 480 V
The Siemens SIRIUS 3RT2038-3AL20-ZW97 is a Size S2 power contactor rated 65 A at 480 V, meaning it handles motor loads up to 65 A in AC-3 duty — the standard induction-motor switching category — without derating at that voltage. The 230 V 50 Hz coil pulls 0.36 VA at 50 Hz and 0.39 VA at 60 Hz, a light control-circuit load that leaves headroom on a 24 VDC or 230 VAC transformer. Spring-type terminals on the coil speed wiring: no screwdriver needed for the control wires. The main contact configuration is 18 N/O and 1 N/C, giving you 18 normally-open power poles and one normally-closed auxiliary — enough to switch a three-phase motor plus a holding circuit without an add-on block. Side clearance is only 6 mm; upward, downward, and forward clearances are 10 mm each.
Duty Ratings and Mechanical Life
The 3RT2038-3AL20-ZW97 carries separate maximum operating rates per duty class: 700 operations/hour in AC-1 (resistive loads), 500 ops/h in AC-3 (squirrel-cage motors, starting and running), and 150 ops/h in AC-4 (plugging, inching, reversing). AC-3e, the energy-efficient motor variant, also maxes at 500 ops/h. These aren't continuous ratings — they're the maximum switching frequency the contactor can sustain without exceeding thermal limits. For a conveyor running one start/stop per minute, AC-3 at 60 ops/h is well within the 500 ops/h ceiling; a reversing application at 2 reversals per minute hits 120 ops/h and stays under the AC-4 limit of 150 ops/h. Mechanical life is 10 million cycles typical, so the contactor outlasts most panel designs.
Auxiliary Contact Ratings and Wiring
The built-in auxiliary switch is rated across multiple voltage levels: 10 A at 24 V, 2 A at 48 V and 60 V, 1 A at 110 V, 0.9 A at 125 V, 0.3 A at 220 V, and 3 A at 400 V (-). At 230 V the auxiliary carries 15 hp — a motor-starting rating, not a continuous thermal current. The wire range for the main and auxiliary terminals is 2x 0.5 to 2.5 mm² solid or stranded. That's a standard 1.5 mm² or 2.5 mm² control wire; no ferrule needed for the spring-type coil terminals. Arcing time spans 10 to 20 ms, and the contactor operates across -25 to +60 °C ambient, with storage from -55 to +80 °C.