MRO Magazine

Preventative maintenance monitoring in a hydropower plant


May 4, 2012
By PEM Magazine

CAS DataLoggers recently provided the data acquisition solution for a hydropower plant setting up hydro turbine condition monitoring for preventative maintenance.

Personnel worked without any clear indications of the hydro turbine’s status for detection of developing equipment problems that could help safeguard against critical damage. Therefore management needed to monitor and analyze various plant parameters including shaft vibration measurement, bearing vibration measurement, generator air gap measurement and plant process signals including mV, mA, RTD, TC, pulse, PLC communication data, etc. Maintenance and commissioning engineers needed a single integrated system to process all these measurements, setup alarm functions, and perform diagnostic analysis. This system would also have to easily integrate into the existing company network via an Ethernet connection to give easy accessibility to any department depending on the access rights. With this in mind, management began searching for an efficient, cost-effective and reliable solution.

The hydropower plant installed a modular and scalable Delphin TopMessage data acquisition system in an industrial enclosure which was then DIN rail-mounted and fitted to a control cabinet. The TopMessage was then connected to a wide range of sensors and began monitoring the plant’s machinery for vibration, temperature, humidity, electrical power, etc. An adjacent bearing block shaft was connected to vibration sensors at each of its 2 ends, where 2 ICP converters were connected to the sensors and to the TopMessage. Sensor inputs were true differential and consequently ensured a high level of accuracy, while the Delphin system’s integrated AMDT/V2 module enabled vibration analysis and monitoring and acquired vibration/process signals and PLC communication data synchronously. The TopMessage was connected to the plant’s network using its Ethernet connection and sent all the data remotely to an office PC while also recording onto its internal 1GB data storage capacity.

Additionally, Delphin ProfiSignal software provided users with a full development environment to easily configure their individual HMI screens and control panels, giving the control room operator a maximum overview of equipment status. The TopMessage’s powerful software channels were used to configure several alarm functions with the ability to switch outputs, to regulate the equipment, and to initiate emergency shutdowns when necessary. The system’s integrated event channels reported any limit violations through SMS and email messages, and users also configured an alarm table giving them a consolidated overview of the plant’s status. ProfiSignal provided a convenient analysis through a seamless transition between online and historical offline data, also enabling online trend plotting and evaluation.


The hydropower benefited significantly following installation of the Delphin TopMessage DAQ system. The main advantage of the TopMessage was that this one solution performed all measurement, monitoring and alarm management functions, and could also be easily adapted to the plant’s individual applications using any number of inputs. The Delphin system’s powerful diagnostic analysis functions gave users a clear indication of the hydro turbine’s status and immediately pinpointed any area developing a problem. This early detection system prevented the plant’s equipment from sustaining major damage and also gave personnel an indication where to focus during the next maintenance stop. Additionally, the TopMessage’s Ethernet connection gave plant departments instant data accessibility and transparency. The plant has since been operating continuously and reliably with very little downtime.