Paralleling System Keeps Power Primed

Jan 1, 2000 12:00 PM, Edited by Ellen Parson, Managing Editor

New gensets enable adhesives manufacturer to ensure reliable power, control peak demand, and save money through utility rebate program.

When Minnesota-based adhesives manufacturer H.B. Fuller began looking for a reliable and sophisticated integrated standby power system to back up power in critical laboratory areas, the staff had to keep several factors in mind. First of all, the company needed to provide long-term backup power to mechanical systems at the central plant for life-safety reasons.

It also had to ensure research and development experiments are not lost during utility power failures or peak load shaving times as well as provide power to serve critical fume hood exhaust air systems and run heating equipment supply and return fans.

The company's plans for a new 140,000-sq-ft research center called for two gensets in parallel at the initial installation, each providing 1,250kW, with room and capability to add a third and fourth for backup redundancy.

Although a smaller 750kW generator had satisfied emergency needs for the past 15 years, it wasn't big enough to handle the needs of the new building, says Dave Massey, technical manager of building operations.

The kilowatt size, coupled with the desire to take advantage of digital control technology, led Tom Goetz, project manager with Peoples Electrical Contractors, to recommend the Cummins Onan PowerCommand paralleling system.

"My criterion was that it be microprocessor-controlled. The PowerCommand digital paralleling system with advanced microprocessor-based controls integrates all genset and paralleling functions," says Goetz. "With one touch to the screen, the digital master control comes to life."

Because all three L-L or L-N voltages or line amperage readings are on one screen, you can easily see voltage and load balance. With the help of color-coded displays, operators can quickly determine if the gensets are overloaded. Special protection circuitry responds to overcurrent conditions and initiates shutdowns when alternator current exceeds specified levels.

In addition to easier maintenance, the client also gets utility discounts from its supplier, Northern States Power Company. The gensets enable H.B. Fuller to participate in a monthly peak-controlled tiered service plan, which spreads utility savings over a year in return for an agreement to shed a given amount of power usage during peak-demand times.

"The gensets enable us to control peak demand, which gives us the ability to control our utility bills and participate in the utility agreement," says Massey. "How that success translates to savings is something H.B. Fuller will be measuring for the next five to 10 years."