Monitoring motor vibration is an important function in an industry as motors being the prime mover of the machineries, which either can drive a single unit like a gear box or a complex machinery like a centrifugal pipe casting machine, failure of the motors, in both type of equipments, can lead to the complete stoppage and loss of production. Abnormal high vibration in a motor is an effect caused by various factors, both electrical and mechanical such as electrical unbalance, mechanical unbalance of rotor, internal effects like looseness, rubbing, bearing problems and external effects like weak or cracked base, misalignment, resonance, critical speeds. etc. With proper knowledge and diagnostics procedures it is normally possible to quickly pinpoint the cause of vibration if the root cause is limited within one or few of the usual causes as listed but if another uncommon cause compounds with few of the common causes and leads to the high vibration of the motor then erroneous conclusions are reached as a consequence of not understanding the root cause of the abnormal vibration which results in trying to fix an incorrectly diagnosed problem. In this paper it has been shown, with a case study, how laying of the motor’s power supply cables, which is normally assumed not being a cause of motor vibration, played a significant role in contributing as one of the causes of abnormal vibration in a blower unit motor of a gas booster station and the same was finally detected after initial diagnosing & eliminating the usual causes for the abnormal vibrations and this resulted in spending a significant amount of time and money in the process
