CONTROLLING METHOD FOR AIR FLOW RATE OF MOTOR COOLING FAN

摘要

PURPOSE:To save electric power by cooling a motor with air flow rate corresponding to the variation in atmospheric temperature. CONSTITUTION:The atmospheric temperature at the periphery of a motor detected by an atmospheric temperature sensor 2 is converted by a temperature indicating regulator 3 into a voltage. This voltage is converted by a function generator 4 into the prescribed voltage, and inputted to a variable voltage to variable frequency converter 6 through an automatic-manual switch 5. The converter 6 converts the input voltage into a frequency on the basis of the relationship between the predetermined atmospheric temperature and the air flow rate, and controls a motor 7 for a cooling fan on the basis of this frequency.