Generator Condition Assessment Through EMI Diagnostics

EMI (electromagnetic interference) Diagnostics is an on-line test that can detect a wide variety of defects in generators and associated electrical systems. Trending data is not necessary to develop maintenance recommendations. This paper provides examples of generators in good condition as well as some that need maintenance. Verification of generator maintenance is also presented. Photo 1 shows the preferred RFCT (radio frequency current transformer) location to collect generator data. This conduit goes from the stator winding neutral to a grounding transformer. The split core RFCT is temporally placed around the conduit while data is collected and is then removed.