What it is and what it handles
The Siemens SIRIUS 3RT2038-1AB04 is a Size S2 power contactor built for motor switching in industrial control panels. Its headline AC-3 rating of 65 A at 480 V means it can handle a 3-phase induction motor drawing that current under starting and running conditions — the duty cycle that governs most conveyor, pump, and fan loads. At 230 V it's rated for 15 hp, which aligns with common North American motor frames in the 10–15 hp range. The coil pulls 24 V at 50 Hz, and the main contacts are configured as 3-pole normally open. There's no built-in auxiliary switch block — you'll add a separate SIRIUS auxiliary contactor or side-mount block if you need status feedback or interlocking.
Mechanical fit and panel integration
Mounts via screw or snap-on onto 35 mm DIN rail per DIN EN 60715. The S2 footprint is 55 mm wide, 114 mm tall, and 174 mm deep — that depth includes the arc chamber and coil overhang, so watch the gland plate clearance when you slide it into a shallow enclosure. Clearance spacing: 10 mm upwards and forwards, 10 mm downwards, 6 mm at the sides. The mounting position is flexible — ±180° rotation on a vertical surface, and ±22.5° tilt forward/backward — which helps in tight retrofit panels.
Switching duty and thermal limits
This contactor is rated for different switching frequencies depending on the duty category: 700 operations per hour at AC-1 (resistive loads), 500/h at AC-3 (motor starting/running), and 150/h at AC-4 (plugging/reversing/inching). The AC-4 limit is the one that bites if you're doing frequent reversing — 150 ops/h means about one every 24 seconds, which is fine for most jogging but not for high-cycle indexing. Mechanical life is 10 million operations typical. Operating temperature range is -25 to +60 °C; storage range is -55 to +80 °C.
Lifecycle and sourcing
The lifecycle stage is marked as current, meaning Siemens still lists it as an active catalog number. No successor order code is indicated — this is the current production variant. For a BOM line that calls out 3RT2038-1AB04, fit is confirmed by the AC-3 current rating and the S2 frame size. Sourced and quoted to order against an RFQ through independent distribution; availability and current pricing confirmed at quote time.