Description
The 3TB40 22-0XM0 is a 3-pole AC contactor from the Siemens 3TB4 series, rated at 9 A (AC-3, 400 V) / 25 A (AC-1, ≤60 °C) with a 4 kW motor-power rating at 400 V three-phase. The “22” denotes 1 normally-open + 1 normally-closed auxiliary contact built into the Size S00 frame, and the “0XM0” coil code specifies AC 50 Hz / 220 V control voltage with screw-terminal connection. Engineered for motor starting, stopping, and reversing duties in IEC 60947-4-1 compliant panels, it serves as the workhorse switching element in pump starters, conveyor drives, fan circuits, and HVAC compressor contactor panels where a compact 9 A frame and 10-million mechanical-life durability matter more than raw ampacity.
h2 Application Scenarios
In a regional water-treatment plant’s lift-pump MCC, the #2 raw-water pump (4 kW / 400 V IE3 motor) was originally switched by a 15-year-old 3TF40 clone that had begun buzzing at coil pick-up and occasionally welded on drop-out during weekend storm surges. The plant’s I&C tech noted that the old contactor’s arc chute had carbon-tracked to the point where the “contactor chattered” whenever the 220 V AC coil supply sagged 8 % during a neighboring 45 kW VFD start. The retrofit dropped in a 3TB40 22-0XM0 — identical DIN-footprint (Size S00), same 220 V AC 50 Hz coil, same screw-terminal landing, but with Siemens’ unsaturated-resin closed arc chute and fully enclosed conductive parts. The aux contacts (1NO+1NC) wired straight into the ET 200SP DI card for “contactor picked up” and “thermal-alarm” feedback, replacing a separate aux-block that had worked loose on the old 3TF. Post-swap, the #2 pump logged zero chatter events through the next monsoon season, and the stores team standardized the 3TB40 22-0XM0 across all five lift-pump starters — one SKU covers the 3 kW, 4 kW, and 5.5 kW pumps in the same MCC row (all within the 9 A AC-3 envelope at 400 V).
h2 Parameter
| Main Parameters | Value/Description |
|---|---|
| Product Model | 3TB40 22-0XM0 (3TB40220XM0) |
| Manufacturer | Siemens |
| Product Category | AC Contactor (3-pole) |
| Rated Operating Current | 9 A (AC-3, 400 V); 25 A (AC-1, ≤60 °C) |
| Motor Power Rating | 4 kW @ AC-3 400 V (3-phase) |
| Coil Voltage / Frequency | AC 220 V / 50 Hz |
| Auxiliary Contacts | 1 NO + 1 NC (built-in) |
| Size / Frame | Size S00 (compact, 45 mm width class) |
| Connection Type | Screw terminals |
| Rated Insulation Voltage | 690–1000 V |
| Mechanical / Electrical Life | 10 million / 1 million operations |
| Mounting | DIN rail 35 mm or screw-fix (panel) |
| Standards | IEC 947 / VDE 0660 / GB 14048 |
| Net Weight | ~0.445 kg |
h2 Technical Principles and Innovative Values
Innovation Point 1: Closed Arc Chute in Unsaturated Resin. The 3TB40 22-0XM0 uses an unsaturated thermoset resin arc-chute housing with enclosed conductive parts — no live metal visible from the front, and the arc chamber is a sealed pocket that confines flash to < 5 mm “fly arc” distance. That lets MCC builders shrink compartment depth by ~20 mm versus older 3TF clones with open-top chutes, and it keeps carbon tracking off the coil housing during the 1-million-operation electrical-life window.
Innovation Point 2: Size S00 Footprint with 1NO+1NC Factory-Built. Many 9 A contactors in this class either skip aux contacts (forcing a front-mount Z-block) or only give you 1NO. The 3TB40 22-0XM0 integrates 1NO+1NC into the molded frame — one contact for “motor running” lamp / DI feedback, one for “thermal trip” or “reverse-interlock” logic — without adding width. In a packed MCC bucket where three starters share one 200 mm DIN row, that saved 18 mm per bucket versus a +Z-block config.
Innovation Point 3: 10 M / 1 M Life Tuned for AC-3 Motor Duty. The 3TB4 series mechanical life (10 million ops) and electrical life (1 million at AC-3) are spec’d for motor-starting profiles — high inrush (6× rated) at make, inductive-decay at break. The 3TB40 22-0XM0‘s silver-cadmium oxide (AgCdO) tips and spring-assisted closing mechanism hold contact resistance stable through the first 500 k cycles, which is why a 4 kW pump starter on 8-hour duty can run 5–7 years before tip inspection.
Innovation Point 4: 220 V AC 50 Hz “XM” Coil with Hum Suppression. The 0XM0 coil is AC 50 Hz / 220 V (not the 50/60 Hz universal), meaning the laminated EI core and shading coil are tuned for 50 Hz hum minima. In a control-panel where the coil supply shares a 220 V transformer with other contactors, the 3TB40 22-0XM0 picks up clean at 0.85 × Us (187 V) and holds through 0.7 × Us (154 V) — important when the MCC’s control-transformer sags during a big-motor DOL start on the same incomer.
h2 Application Cases and Industry Value
A food-processing chill-room running four 4 kW ammonia-pump motors had its original 3-pole contactors (non-Siemens brand) failing every 14–18 months — the combination of 4 °C ambient, periodic defrost-cycle humidity spikes, and the pumps’ 7× inrush was pitting the tips faster than the 1 M spec. The retrofit swapped all four to Siemens 3TB40 22-0XM0, reusing the existing 220 V AC 50 Hz control wiring and the DIN-rail mounting holes. Eighteen months later, contact resistance checks on all four units showed < 0.8 mΩ (vs. original’s 2.1–3.4 mΩ at pull-out), and the chill-room’s “pump starter alarm” tickets dropped from ~6 per year to zero. The plant’s electrician noted two gains: first, the enclosed conductive parts meant no stray condensation paths to the coil terminals (the old open-frame units had corroded screw heads); second, the 1NO+1NC aux let them land “pump running” DI and “thermal OL trip” DI on the same contactor without an add-on block that used to vibrate loose on the old units. The stores team subsequently dropped the old contactor SKU and standardized 3TB40 22-0XM0 for every ≤5.5 kW pump/fan starter in the facility.
