Machinery protection solution passes with flying colours

The ability to quickly identify issues affecting the performance of rotating plant, as well as being able to optimise dynamic behaviour, is vital to all plant engineers.

“Established and proven monitoring systems, like the Sentry G3 machinery protection system from SENSONICS, combines the flexibility of hardware in a single, easy-to-install and easy-to-use module type for all sensors and so is a highly effective solution,” says the company. “The system is compliant to API 670, so meets the most stringent protection requirements, in addition to meeting IEC 61508 up to SIL-3 standards.”

The Sentry G3 system is being continually developed to meet the ongoing challenges and also those arising from specific applications, such as for gas turbine upgrades at major UK nuclear power stations. “For these applications, ‘Emphasis’ audits are considered to be the most complex and rigorous (for software) and users will be assured that Sentry G3 meets these standards.”

Device compliance with IEC 61508

The emphasis method assesses a device’s compliance with IEC 61508 for functional safety standards, along with other requirements specific to the UK nuclear industry. “It provides end users with the confidence that both the hardware and software components in these protection systems meet the required high levels of design, testing and production, which minimises the risk of systematic failures,” adds SENSONICS.

Advanced features include: vibration, position and speed parameter trending facilities, including log and view of up to 60 days of data, ‘look back’ at trends and alarms, plus download data for further analysis in Excel. It is also now possible to directly view proximity probe gap and vibration transducer bias voltages, to verify correct transducer operation and calibration.

The Sentry G3 single module concept minimises the need for spares holdings helping to reduce ongoing maintenance costs whilst also lowering the risk in retrofitting applications where the need to interface monitoring systems quickly and correctly with previously installed sensors is key.

Fully software programmable and upgradable

The system is fully software programmable and upgradable, which ensures adaptability moving forward as inevitably application requirements change. It’s also easy to expand, simply by adding additional G3 monitors. It offers excellent channel density with up to 24 measurement channels housed in a compact 3U x 19” rack mounted format which can halve the space needed on existing installations.

Multiple outputs are available on the back of the rack for up to 3 alarm levels and 2 analogue outputs per channel. Dual redundant Modbus communications to a module level provide a robust communication system, while the in-built LCD display offers readings, sensor integrity voltages, trending and FFT, all of which confirm the accuracy of the installation.

Sentry G3 plus points

In summary, Sentry G3 is said to provide “state-of-the-art, flexible, easy-to-install and maintain space-saving protection” for the following modes:

• Measurement – absolute bearing and relative shaft vibration, shaft position and thrust wear, speed, phase and reverse rotation, differential and casing expansion, rod drop and temperature.
• Turbine Specialist Measurement - shaft eccentricity, order tracking, dynamic pressure and mark - space differential expansion.

“The additional features incorporated into the latest Sentry G3 system ensures more than just machine protection,” SENSONICS concludes, “providing a set of tools to assist plant engineers to optimise the control and management of their rotating plant now and into the future.”