| 摘要 |
<p>PURPOSE:To prevent a motor from being exothermic and damaged by executing the motor overload cutout process when the frequency of the motor current maximum value of every first unit time exceeding the first reference value exceeds the second reference value. CONSTITUTION:The motor current maximum value within the first unit time is obtained on the basis of the motor current value every fixed first unit time, and the motor current maximum value is discriminated whether or not it exceeds the first reference value. The frequency of the motor current maximum value of every first unit time exceeding the first reference value is calculated every second unit time which is longer than the first unit time, and this frequency is discriminated whether or not it exceeds the fixed second reference value. When the calculated value is discriminated to exceed the second reference value, the motor overload cutout process is executed. As a result, even in case the motor current varies periodically at the shorter cycle than the second unit time and such as to exceed the first reference value, the motor 1 is surely prevented from being exothermic and damaged.</p> |
