A particular area of the plant has a high rate of motor failure. The repair techs have noted problems such as burned windings or the grease baked into a fairly hard cake. The plant engineer says heat is the common denominator in most of these motor failures. He wants you to determine the root cause and identify a means to monitor and prevent it in the future.
He said he suspected voltage imbalance, and sent the electrical drawings to an engineering firm; this outside firm confirmed