Many cooling towers in place today operate below their maximum capability due to a number of factors. When setting the blade pitch, it is common for the cooling tower manufacturer to set the pitch a little lower than the pitch which would result in full amp draw from the motor. This allows for some "extra" capability on days where the temperature and humidity of the air cause the load on the motor to increase. This paper discusses a control scheme by which real time motor temperature data is used to insure maximum output while simultaneously protecting the motor from an overheating condition.
10-11: A New Control Scheme Provides the Most Cooling for Your Money
Robbie McElveen, Baldor Electric Company and Mike Daley, Hudson Products Corporation