Resolving rotating machinery asset signal issues detected by the Emerson’s 6500 ATG Protection System

A large public natural gas utility company using Emerson's advanced 6500 ATG Protection System installed on power generation units.

The customer has Emerson’s 6500 ATG Protection System installed on the generator and detected a signal issue which prompted a call to Novaspect, an Emerson Impact Partner, to investigate and provide actionable recommendations. Novaspect’s Reliability Services Specialists performed troubleshooting to diagnose the spiking vibration signal and determined it was coming from a poor connection at the velocity sensor. However, the system health check and service work needed to be postponed until the customer could schedule a shutdown for the affected unit and avoid a costly unplanned outage.

During the customer’s planned shutdown, Novaspect completed the system health check and discovered the velocity sensor cable connectors are a slip-on style environmental connector and the contact felt loose and weak on most of them. The technician performed a simple connection “wiggle” test while monitoring the 6500 ATG Machine Studio software which recorded approximately 120 mils on the sensor after an extremely light touch. This spike in energy would have resulted in a trip and shutdown of the generator.

Novaspect replaced the loose velocity sensor connector cables with screw-on style connectors which provide a positive electrical connection and have a low risk of accidental disconnection.





 

However, after further monitoring, a new erratic signal surfaced from the card, so the technician completed additional testing on the ATG rack and junction box and discovered a bad sensor and cable for the proximity probe and velocity sensor.

Novaspect’s technician inspected the back panel of the ATG and found loose wire connections at the phoenix connectors on 3 cards on a wire for the proximity probe sensors. The connection also had two wires utilizing the same terminal which easily pulled out of the phoenix connector after applying tension.



The sensors and cables on the back panel of the ATG were likely damaged due to excessive heat, so the technician replaced them with wire ferrules which are a reliable conductor and ensure a confident connection that is easier to insert, especially when spliced or when using multiple wires.

Because the customer had enabled Emerson’s 6500 ATG protection system, they could easily monitor their gas turbine generator and analyze its live waveform data in Machine Studio which helped them detect abnormalities and troubleshoot problems before any unplanned outages could occur.

Novaspect assisted by replacing connections and cables with equipment that is better suited for the customer’s operations.  Additionally, Novaspect’s Reliability Services Specialists perform Scheduled System Maintenance (SSM) on a regular basis to inspect and calibrate the 6500 ATG system and to update software and firmware while the unit is in shutdown or when the shutdown protection system is in bypass.

This comprehensive approach, from connector replacement to scheduled maintenance, demonstrates the importance of proactive measures in maintaining the health and performance of vital power generation systems.

Don't leave your plant's reliability to chance. Improve reliability by spotting problems with state-of-the-art technology before they affect your process. Contact the experts at Novaspect, your local Emerson Impact Partner, to learn more about how we can help.