Many IT and telecommunications companies use fans to cool sensitive electronics in data centers or cellular network base stations to guarantee the desired availability for their customers. So they replace the fans at regular intervals with plenty of time to spare before the specified service life expires.
But hardly any fan operates constantly at its speed or temperature limit. They could work much longer than they actually do. ebm-papst’s FanCheck software resolves this dilemma and calculates the service life based on actual operation. This results in a considerable reduction in material and replacement costs.
A fan’s service life depends primarily on its bearing, which is the weakest link in the entire product. So FanCheck focuses on this component for its service life calculations.
The speed at which a fan’s bearings wear out depends primarily on its speed and operating temperature. Both values are recorded as standard for most ebm-papst products. The higher these parameters are over the entire service life, the faster the bearing will wear out.
At the beginning of its lifecycle, every fan gets service life points (credits). This figure (in the millions) varies depending on the size and design of the fan. The number of credits can also be adjusted during the fan’s design. For example, it can be reduced if the fan operates under especially hot or humid conditions.
FanCheck records the temperature and speed of a fan every second. A database in the microcontroller stores information about how many credits have to be deducted for each combination of speed and temperature values. This value is summed every second. After one minute, FanCheck subtracts the credits to be deducted from the remaining service life and writes the result to a non-volatile memory. The information from the database is based on experience gathered by ebm-papst over decades in the field and in endurance tests.
The customer can specify at which time and in which way the fan is to provide status information or warnings; it can closely monitor the remaining service life or trigger an alarm when it goes below a previously set value. In this way, FanCheck can be easily integrated into existing control systems.