Siemens 3RT2038-1NB34 — SIRIUS Size S2 Power Contactor
The coil accepts 20-33 VAC/DC, with a pick-up threshold at 0.8x rated and drop-out at 1.1x full-scale value — meaning it holds in reliably down to about 16 V and releases cleanly above 36 V. Main contacts are configured as 3-pole normally open (3 NO), rated for AC-1, AC-2, AC-3, and AC-4 duty cycles. At AC-3 (motor switching), the maximum operating rate is 500 cycles per hour; at AC-4 (inching/jogging), it drops to 150 cycles per hour due to higher arc stress.
These spacings ensure adequate arc-quenching and heat dissipation in a crowded panel.
Coil terminals are screw-type, accepting 2x 0.5 to 2.5 mm² solid or stranded wire. At 24 V rated value, holding current is 6 A; at 48 V it drops to 2 A, and at 220 V to 0.3 A. These timing figures matter for coordination with upstream short-circuit protection devices — the arc must clear before the breaker's magnetic trip reacts.
The SIRIUS series typically carries UL, CSA, and CE certifications (confirm specific marks with the factory datasheet). RoHS and REACH compliance documentation is available from the manufacturer.