The **W2AC-AA4A-R2/Q** is a specific high-performance industrial cooling fan assembly, typically manufactured by brands like **Sanyo Denki** (San Ace line). This model is a 120mm AC-powered axial fan designed for reliability in server racks, industrial control panels, and telecommunications equipment. --- ### 1. Technical Specifications Below are the primary electronic and mechanical characteristics of the unit: | Parameter | Specification | | :--- | :--- | | **Input Voltage** | 100V - 115V AC (Single Phase) | | **Frequency** | 50 / 60 Hz | | **Frame Size** | 120mm x 120mm x 38mm | | **Bearing Type** | Dual Ball Bearing | | **Material** | Aluminum Frame / Plastic Impeller (UL94V-0) | | **Termination** | Lead Wires (typically 2-wire for standard AC) | | **Operating Temp** | -30°C to +70°C | --- ### 2. Key Electronic Components & Features #### A. The Induction Motor Unlike DC fans that use brushless electronic commutation, the W2AC series utilizes an **AC Induction Motor**. * **Stator:** Consists of copper windings that create a rotating magnetic field when connected to the AC line. * **Rotor:** A permanent magnet or squirrel-cage rotor that follows the stator's magnetic field. * **Insulation:** The windings are Class E or Class B insulated to prevent short-circuiting under high thermal stress. #### B. Bearing System (Dual Ball) The "/Q" or "R2" suffixes often denote specific revisions or bearing upgrades. Dual ball bearings are used to: * Support high-speed rotation (approx. 2600–3000 RPM). * Ensure a long service life (MTBF of ~40,000 to 70,000 hours). * Allow the fan to be mounted in any orientation (vertical or horizontal) without leaking lubricant. #### C. Burn-out Protection The electronics include **Impedance Protection**. In the event the fan blades are locked (prevented from spinning), the impedance of the motor windings is high enough to limit the current, preventing the coils from overheating and catching fire. --- ### 3. Part Number Breakdown (General) While specific to Sanyo Denki/San Ace nomenclature, the code generally follows this logic: * **W2AC:** AC series axial fan. * **AA4A:** Dimensional and performance code (120x38mm). * **R2/Q:** Revision markers indicating specific airflow curves, noise optimizations, or environmental ratings (like moisture resistance). --- ### 4. Application Use-Cases 1. **Industrial Cabinets:** Exhausting heat from PLCs and Power Supplies. 2. **Server Enclosures:** Providing constant airflow in AC-fed rack environments. 3. **Vending Machines:** Reliability in environments with variable ambient temperatures.