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  • On-line partial discharge
  • Electromagnetic interference survey
  • Iso-phase bus condition assessment
  • Generator condition assessment
  • Motor condition assessment
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Iso-Phase Bus Condition Assessment

What is the condition of your isolated phase bus that delivers power from your generator to transformers? Consider the consequences to your plant operation if your bus fails.

Identify loose bolted connections in your bus duct with EMI Diagnostics^SM.

An Electromagnetic Interference (EMI) Diagnostics survey from Doble is an on-line,non-invasive test that can detect a wide variety of defects in isolated phase bus duct, transformers, generators, motors and associated electrical system components that other technologies are unable to detect.

Phase 1: Loose Connections
Problems with iso-phase frequently begin with loose bolted connections which causes pitting and discoloration due to heating and arcing in the early stages of the developing problem. At this point, heat generated is not likely to heat the bus duct enclosure, but the defect will produce an electromagnetic field which can be detected by EMI Diagnostics.

Phase 2: Melting of the Metal
If allowed to continue, heating will melt the metal. Current is still flowing and at this point discharge activity would be obvious on the EMI Diagnostic survey. You may be able to detect the problem with infrared scanning techniques at this point. Do you want to wait until the problem reaches this point before detection? Even now, time consuming and costly repairs are needed.

Phase 3: Failure
It does not take long to get from phase 2 to complete failure. At this point, a forced
outage will shut down the generating unit and the cost will include lost production
as well as the cost of replacing the iso-phase bus connection. This could have been prevented with an annual EMI Diagnostics survey from Doble.