Fan speeds of 90 to 230 RPM are normal for cooling tower fans. In cooler climates, the fans can be reversing to prevent freeze during the winter. The most common Cooling Tower Fan failure involves the gearbox or fan blades and is catastrophic in nature. In many cases, this type of failure leaves the gearbox and fan blades lying in the cooling water pond at the bottom of the tower. Although questionable to start with for this application, over time most of these devices have quit working due to corrosion or neglect.
Permanent monitoring is the recommended solution for preventing cooling tower cell failures.
Periodic measurement programs rarely produce the desired result. In most cases, the location and environment discourages any attempts to take data or visually inspect the fan. Permanent monitoring of a cooling tower fan cell requires direct monitoring of the most important component by mounting a transducer directly on the gearbox. Additionally, knowledge of the expected vibration frequencies is important. Speed 90-300 RPM 2.