The **MAH28FAX-R** is an industrial-grade, high-performance DC fan manufactured by **Sanyo Denki** (San Ace). It is part of the Long Life fan series, designed for applications requiring high reliability and continuous operation. --- ### 1. Key Technical Specifications The electronics of this part are engineered for high-static pressure and durability. | Feature | Specification | | :--- | :--- | | **Input Voltage** | 24V DC | | **Operating Voltage Range** | 20.4V to 27.6V | | **Rated Current** | 1.8A | | **Rated Input Power** | 43.2W | | **Rated Speed** | 6,400 RPM | | **Maximum Airflow** | 275.4 CFM (7.8 m³/min) | | **Max Static Pressure** | 400 Pa | | **Sound Pressure Level** | 64 dB(A) | --- ### 2. Electronic Component Details #### A. Motor Construction * **Brushless DC (BLDC) Design:** The fan uses a 3-phase brushless motor, which reduces mechanical wear and electromagnetic interference (EMI). * **Drive Circuitry:** Integrated electronics handle the commutation of the motor, eliminating the need for an external motor controller. #### B. Bearings and Longevity * **Dual Ball Bearings:** The "Long Life" designation comes from high-precision dual ball bearings. * **Expected Life:** Rated for approximately **100,000 to 180,000 hours** at 40°C (depending on the specific sub-model environment), which is significantly higher than standard consumer fans. #### C. Control and Monitoring (Wiring) Typically, the MAH28FAX-R features a 3-wire or 4-wire lead system: 1. **Red (+):** Positive power supply (24V). 2. **Black (-):** Ground/GND. 3. **Yellow (Sensor):** Tachometer (FG) signal. This outputs a square wave that allows the system to monitor the actual RPM of the fan. 4. **Brown (Control):** In PWM models, this allows for external speed control. --- ### 3. Protection Features The internal PCB includes several protective electronic circuits: * **Locked Rotor Protection:** Prevents the motor from burning out if the blades are physically obstructed. It automatically attempts to restart once the obstruction is removed. * **Reverse Polarity Protection:** Prevents damage if the positive and negative wires are accidentally swapped during installation. * **Thermal Protection:** Sensors on the PCB reduce power if the internal temperature exceeds safe operating limits. --- ### 4. Typical Applications Due to its high static pressure and reliability, it is commonly used in: * **Server Racks:** High-density cooling for data centers. * **Industrial Inverters:** Cooling power electronics in manufacturing. * **Telecom Base Stations:** Outdoor enclosures where long-term maintenance-free operation is required.