SIRIUS S2 Power Contactor, Spring-Terminal, 20-33 VDC Coil
The Siemens 3RT2036-3NB34-3MA0 is a SIRIUS-branded Size S2 power contactor, built for switching motor loads and resistive circuits in industrial control panels. Its coil is rated for 20 to 33 VDC, and the terminals on the magnet coil are spring-type — tool-free wiring on the control side, which saves time during panel build and commissioning. It mounts via screw and snap-on onto 35 mm DIN rail per DIN EN 60715, with the mounting position allowing ±180° rotation on a vertical surface and ±22.5° tilt forward or backward. That flexibility helps when you're shoehorning it into a crowded enclosure.
Mechanical Fit and Panel Clearances
The 3RT2036-3NB34-3MA0 measures 55 mm wide, 114 mm high, and 178 mm deep. For side-by-side mounting, allow 6 mm clearance at the side, 10 mm upwards, 10 mm forwards, and 10 mm downwards. Those gaps are tight enough for dense rail layouts but worth checking if you're retrofitting into an existing panel with fixed barriers.
Switching Performance and Duty Cycles
This contactor handles 1 000 operations per hour at AC-1 (resistive load), 800 ops/h at AC-3 (standard motor starting), and 250 ops/h at AC-4 (plugging/inching). For AC-3e it also rates 800 ops/h. The arcing time sits between 10 and 20 ms, and the opening/closing times are 30 to 55 ms for both AC and DC coils — consistent, predictable switching for sequencing logic. Coil inrush peaks at 3 A, then holds at 6 A at 24 V rated value, dropping to 0.3 A at 220 V rated value. The holding power draw is 2 VA at both 50 Hz and 60 Hz, so the control transformer sizing is straightforward.
Environmental Range and Wiring Details
Operating temperature spans -25 to +60 °C; storage range is -55 to +80 °C. The main contact wiring accepts 2x (0.5 to 2.5 mm²) solid or stranded conductors — spring-type terminals on the coil side, screw-type on the main contacts. No auxiliary switch is included on this variant (the -3MA0 suffix indicates a specific auxiliary configuration), so add a separate auxiliary contact block if you need feedback.
Sourcing and Availability
This is a current-production part with no end-of-life notice. It's sourced through independent distribution and quoted to order against an RFQ. For a BOM freeze or a replacement order, the supply posture is stable — no last-time-buy pressure.