The Siemens 3RT2337-1DA40 is a SIRIUS S2-frame contactor with a 24 VDC coil, rated for 10 A at 230 V AC-1 (resistive load) and 10 A at 24 V DC. It mounts via screw or snap-on onto 35 mm standard mounting rail per DIN EN 60715, with a footprint of 75 mm width, 114 mm height, and 130 mm depth.
The 10 A AC-1 rating at 230 V covers resistive heating, lighting, and distribution loads; for motor starting (AC-3 duty) the main contact rating range is listed as 18 down to 1 A — the actual AC-3 current depends on the motor power and utilization category, so size the contactor to the motor full-load amps, not the AC-1 figure. The DC switching capability spans 10 A at 24 V down to 0.3 A at 220 V, with arcing time of 10–20 ms and operate times of 10–18 ms AC / 50–110 ms DC — useful for DC brake or control circuits. An auxiliary switch is included, saving a separate add-on block for basic status feedback. The terminal accepts solid conductors from 0.5 to 1.5 mm² and stranded from 0.75 to 2.5 mm² — standard for control wiring in a panel.
Mounting and spacing
The S2 frame size allows up to 2 auxiliary contact blocks attachable. Screw terminals are accessible from the front with IP00 protection at the connection point — plan for finger-safe shrouding or enclosure depth to maintain safe separation.