Motor field protection and recommended settings and monitoring

Proper alarm and trip settings of induction motors may not be as obvious or as straightforward as one would believe.. Motor manufacturers can provide recommended control settings, but these settings may not be truly right for generic applications and typical conditions. There are many reasons why a particular operating condition (whether load related or environmental) may be different than the generic one. In certain situations, typical recommended settings might be too high to warn the user of a potential problem, while in others, the settings may be too low, causing nuisance trips. Trending will provide much more insight than relying solely on setting absolute values. It is important to understand any changes that go on within the motor, which could point to a potential on-coming problem. If an alarming trend is identified that cannot be associated with a change in operating conditions, then the motor condition can be better understood.