3RT2024 (size S0, 12 A)
Siemens (SIRIUS) · SIRIUS S0
Siemens' SIRIUS S0 frame: 12 A AC-3 / 5.5 kW @ 400 V. Screw or spring terminals, compact 45 mm width, and the 3RT family runs to 250 kW with the same accessory logic.
Ratings
- AC-3 @ 400 V
- 12 A (5.5 kW)
- AC-1 (resistive)
- 40 A
- Hp (3Φ)
- ≈ 3 HP @ 230 V · 7.5 HP @ 460 V
- Three-phase HP
- ≈ 3 HP @ 230 V · 7.5 HP @ 460 V
Coil data
- Available coil voltages
- Coil code positions 11–12 of the MLFB: e.g. 1A… = 24 VAC, 1A P0 = 110 VAC, 1B… = 24 VDC
- Inrush VA
- ≈ 60–70 VA
- Sealed (holding) VA
- ≈ 8–9 VA
- Pickup voltage
- 0.8–1.1 × Us
- Dropout voltage
- 0.1–0.5 × Us
Typical measured coil resistance (±15%, ballpark)
24 VAC≈ 6–10 Ω
120 VAC≈ 130–230 Ω
230 VAC≈ 500–900 Ω
OL = open coil · near zero = shorted turns · coil-to-frame must read >1 MΩ.
Coil resistance checker
Pick the coil voltage, enter your meter reading across A1–A2 (coil disconnected), and compare it to the expected ballpark.
Ω
This model (24 VAC table value)6 Ω–10 Ω
Generic mid-frame 24 VAC4 Ω–9 Ω
OL = open coil. 0–2 Ω = shorted turns (often from a cooked transformer). Ballpark only (±15%+); electronic wide-range coils (e.g. ABB AF) read misleading values — test those at rated voltage instead. Always measure coil-to-frame too: must be >1 MΩ.
Terminals & accessories
Power/coil terminals: 1/3/5 in, 2/4/6 out; A1(+)/A2(-)
Auxiliary contacts: 1 NO integrated; 3RH29 auxiliary switch blocks snap on front
Companion overload: 3RU21 thermal relay mounts directly underneath
Cross-references
- Schneider LC1D12
- ABB A12 / AF12
- Allen-Bradley 100-C12
- Eaton XTCE012B
Field notes
- Spring-terminal versions are vibration-proof — worth the upgrade on reciprocating machines.
- MLFB decode matters: 3RT2024-1A… vs -2A… is screw vs spring terminal. Get the full part number off the side label.
Siemens (SIRIUS) resources
Links go to the manufacturer's current catalog or product page — model-specific pages are often retired, so these stay live.