Standby power generators add reliability, easy maintenance to new lift stations
|Challenge:||Ecologically sensitive city required reliable standby power for sewage collection system upgrade to increase safety and reduce the risk of sewage backup.|
|Cummins Solution:||Seven Cummins generators ranging from 20 kW to 200 kW, with a sound-attenuated enclosures and compact footprint and transfer switches.|
|Result:||Cummins was chosen for this project based on our ability to understand the critical requirements, respond quickly with the right generator sets and transfer switches and package the units for easy installation and maintenance.|
A necessary upgrade to an ecologically sensitive city’s sewage collection system
Like many expanding suburbs, Camas, Washington, faced the problem of updating its aging sewage collection system to meet the needs of the city’s growing population. Located on the north bank of the Columbia River, adjacent to Portland, Oregon, and Vancouver, Washington, this ecologically sensitive town couldn’t risk any kind of sewage backup if the local electric utility failed. To increase reliability and safety, the city specified that each new lift station include a standby power generator from Cummins Power Generation Inc.
For most of its history, Camas (population: 15,000) relied on gravity-fed lift stations to pipe sewage to the treatment plant. But by the 1970s, Camas had expanded beyond a ridge to the north and a pressurized system became necessary. “Since about 2003 we have been retrofitting existing lift stations and installing new ones in new subdivisions and developments,” said Jim Dickinson, Wastewater Operations Supervisor for Camas. “The new lift stations are pre-engineered and include a Cummins Power Generation standby power generator.” Camas has a total of 20 lift stations; of those, 7 are brand new pre-engineered lift stations.
Lift stations “pre-engineered” for reliability, fitted with Cummins generators
Camas city engineers set several requirements when they began replacing the lift stations. Reliability, easy maintenance and consistency of design and performance were top of the list. Each lift station is pre-engineered by Romtec Utilities, Roseburg, Oregon, to meet those requirements. All components, including structural, mechanical, electrical, power generation and communications, are pre-engineered, delivered as one package and installed in about a week. “We chose Cummins Power Generation for the same reason cities choose us,” said Mark Sheldon, Vice-President for marketing and sales, Romtec Utilities. “They receive our requirements and respond quickly with the right generator set and transfer switch, and they make installation and maintenance very easy.”
A Cummins Power Generation solution for critical performance parameters
The diesel-powered standby generator sets at the Camas lift stations range from 20 to 200 kW and are either permanently installed or portable trailer-mounted units. The power output specification depends primarily on the size of the pump at each lift station, which ranges from 11 to 35 horsepower. From these parameters, Cummins determines the engine, alternator and excitation system for each new lift station. Camas lift stations include Cummins Power Generation OTEC open transition transfer switches, which provide safe “break-before-make” power transfer from the grid to the generator and back again for both testing and power outages. Leaving a programmable gap of several seconds between power sources allows the residual voltage in the lift station’s pump motors to fully dissipate, which is important to protect the generator set’s alternator.
All generator sets are installed in sound-attenuated enclosures so that they don’t disturb the community. “In addition to a low-noise requirement, another ‘must’ for the new lift stations is to use the smallest amount of space possible, sometimes just 1,000 square feet,” said Sheldon.
Relying on Cummins to put it all together
Once a lift station is installed, it’s the job of the Camas wastewater operations staff to maintain them, and easy maintenance and high reliability help reduce the time they spend in the field.
“We rely on Cummins Power Generation not only to design, specify and install the generator, but also to train the operator. These combined factors give us the reliability to know that Camas will keep pumping, whether or not utility power is available.” Mark Sheldon, Vice- President for marketing and sales
For more information about standby power solutions, contact your nearest Cummins Power Generation distributor or visit power.cummins.com.