Motor control apparatus with short term undervoltage motor mode saver

摘要

A microprocessor control motor starter is utilized in which a capacitor-backed random access memory is utilized to store certain critical data about the status of a motor so that if the power supply voltage temporarily drops below a certain value the critical information will not be lost. The microprocessor which controls the motor attempts to reinitialize itself as in the case long term power outage. A subroutine is provided which determines whether the motor can immediately be placed in the state it was in before the power outage occurred, or whether an automatic restart may take place, or whether the motor must be operator restarted manually.