Detecting electrical and mechanical system component problems
Isolated phase bus ducts systems are vital components in power plants that are often overlooked. These iso-phase bus duct systems are the only critical components within the plant that have no redundancy and no quick replacement solutions. On-line, non-invasive diagnostic solutions can be very useful in helping asset owners identify issues before outages, allowing for more efficient outage planning and prioritization of needed repairs.
EMI Diagnostics is a non-invasive, on-line electromagnetic interference survey which provides a broader system view of defects, including partial discharge, and can detect a wide variety of electrical and mechanical system component problems in isolated phase bus, generators, motors, transformers, cables, switchgear and associated electrical system components.
- Performed on-line while plant is in service
- No permanent high-voltage connections
- Detects the radio frequency emissions resulting from partial discharge and arcing
- Maintenance recommendation can be provided upon completion of first test
- Over 8,000 tests conducted since 1980 on over 500 different designs from 25hp to 1400 MW.
- Technology used at nuclear, fossil, hydro, gas turbines, diesel, petrochemical and refineries
EMI data is collected from the temporary placement of a split core radio frequency current transformer around the power conduit, safety ground or neutral lead of the component being tested. No hot connection is required to any energized conductor or hardware installation modifications are required. The acquired radio frequency spectrum, or EMI signature, is unique for each location and type of component. Each defect yields a specific frequency and amplitude that allows Doble to determine the type of anomaly present.
EMI Diagnostics is a proven technology which is a useful and cost-effective way to identify electrical asset issues as well as assets where maintenance is not required – all while the equipment is in-service.
Typical isolated phase bus conditions detected with EMI Diagnostics:
- Loose or broken support insulators
- Loose or corroded hardware
- Defective insulation
- Stray circulating currents
- Foreign material or objects inside bus
- Defective bus PT connections
- Open PT high-voltage fuses
- Contaminated insulators (dirt, dust or water)