International Journal of Engineering Research in Electronics and Communication Engineering

Establishing a Diagnostic Technique for Identification of a Problematic Foundation

Author : Lokesh N Rai ¹ Awtar Narain Mathur ²

Date of Publication :7th February 2017

Abstract: Diagnosis of a vibration problem when the machine has been assembled completely is often tedious. In fact there are several rotating components in a motor assembly which may be responsible for high amplitude of vibrations. In addition, any static component can also generate vibrations. When a rotating machine exhibit large vibrations, often the doubt goes to moving components or the bearings. Efforts are carried out to identify a problem in one of these components, but sometimes it may so happen that no fault is identified in rotating parts or bearings and still the vibrations become uncontrollable. This is exactly what happened in a motor in a Nuclear Power Station having 2 machines each of 236 MW rating. In place dynamic balancing was carried out but it did not help. Frequency analysis revealed some looseness in nuts and bolts but controlling them also could not reduce the vibrations. Ultimately, the recently developed technique of phase measurement and analysis was applied and the problem was diagnosed to be that of faulty foundation system. Appropriate corrections were then made and vibrations were brought down to permissible limits. This paper presents the methodology used in establishing the technique for identification of a problematic foundation, which can be used in case of motors, turbines, generators and alternators et

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