Keeping generator testing under control
Following a successful installation of four resistive/reactive load banks at the Cummins manufacturing plant in Fridley, Minn., Crestchic was awarded preferred partner status.
Cummins Power Generation designs, manufactures, sells, and services diesel engines and related technology. Its Fridley, Minn., facility produces generators that range from consumer models to medium-voltage multimegawatt prime power generators.
Cummins approached load bank manufacturer Crestchic Inc., to design a custom 3 MVA load bank for an integrated test cell project. The team in Fridley wanted a test cell that would last at least 20 yr and be able to keep up with future technological demands and safety requirements.
In response to this specification, the manufacturer recently installed the four new load banks with a combined capacity of 6,400 kVA; they are designed to operate seamlessly with a Crestchic-designed automatic step-down transformer package (see Figure 1). The load bank test cell has the capacity for testing generators with outputs that range from 190 V to 14,000 V at 50/60 Hz.
The large voltage range will be selected and adapted automatically via Cummins PLC-based controls, which means there is no requirement for human contact while reconfiguring voltages and capturing performance data. This will be accomplished using Crestchic's software and hardware engineering integration with the Cummins control and monitoring architecture.
Control systems for testing accuracy
Incorporating a standardized software and hardware platform with MODBUS capability supports the integration of the existing Cummins automated testing software, which works seamlessly with the test subject and test equipment. Crestchic implemented its standardized control system that incorporates redundant safety features, an area of particular interest to Cummins.
Not only has the safety element of the control systems improved the testing process at Cummins, the speed of testing has been improved significantly through the implementation of the Crestchic control systems. Crestchic load banks provide the ability to use Cummins test software to save specific load profiles. In turn, this has streamlined the test process by automating the complete test sequence, improving overall test time.
It was of significant importance to Cummins that the load bank provider use appropriate equipment and components for the application required. For example, the use of oil-filled transformers and tap changers that are typically used in utility power distribution applications was integral. The manufacturer also provided relevant and comprehensive documentation for the equipment specified ahead of the scheduled delivery. This allowed Cummins to prepare for its arrival in advance and minimize downtime risks. In addition, standardized equipment ensures optimum maintenance and spares management.
"Cummins Fridley seeks safe and reliable equipment for our test cells," said Raj Nolambur, manufacturing project engineering manager at Cummins Fridley. "The Crestchic engineering team understood this requirement for which they designed and sourced the appropriate components. The commissioning support demonstrated by Crestchic was second-to-none on this project."
Paul Brickman is the sales and marketing director at Crestchic Inc. He is a seasoned professional in the power industry and has currently been in this position at Crestchic for more than 3 yr. Brickman is responsible for all major customers and markets in the U.S., Far East, and Korea.