Chub Cay Island offers everything that a vacationer, sailor, yachting enthusiast or sport angler could ever envision of a tropical paradise. As part of a cluster of 30 islands and close to 100 cays or reefs that comprise the Berry Islands in the Bahamas, Chub Cay Island covers just 900 acres, with over five miles of white, sandy beaches. The island is 152 miles southeast of Miami Beach, Fla., and has earned an international reputation for its sport fishing, with several world-record catches.

In 1992, Hurricane Andrew wiped out Chub Cay Island and its growing tourism business, but under the guidance of Michael Kaboth, general manager of Chub Cay Club Resort, several years of renovation and construction have brought the island's resort and marine business back to first-class status.

In 1994, Chub Cay Island opened a fully automated, licensed power company, Chub Cay Power & Light, which is designed to provide all of the island's electrical power requirements well into the next century. Four Detroit Diesel Spectrum generator sets produce all of the island's power -- three nominal 350 kW gen-sets and one 450 kW genset, all derated for prime power.

The Spectrum gen-sets, packaged by Kohler Co., were designed and installed by Florida Detroit Diesel-Allison in Miami. Gale Garrett, Florida DD-A generator service supervisor, oversees the installation and said the generators have demonstrated a high degree of performance and reliability. "One unit has logged 12,000 hours without a single glitch, while the other three gen-sets are approaching 9000 hours each," Garrett said.

With derated outputs of 250 and 350 kW, the three smaller gen-sets are powered by Detroit Diesel 6V-92TA diesels rated 330 hp and driving Marathon generators, while the single larger gen-set is powered by a 12V-71TA rated 460 hp, also coupled to a Marathon generator. Kohler Decision Maker 3 controllers provide for gen-set metering, monitoring and safety shutdown features. Other gen-set components include radiators from Modine, silencers and air filters from Donaldson, as well as oil makeup systems from Ren and F.W. Murphy.

While any one of the four generators is capable of providing power for the island, Garrett said typically the 350 kW unit serves as the prime power source with the other three 250 kW gen-sets arranged sequentially in a standby capacity during peak power instances and maintenance', downtimes.

Once the load pushes past 250 kW, a programmable logic controller (PLC) signals another generator to come online and work in parallel with the prime power unit. The system is designed so that during peak power demand -- typically during the island's two annual fishing tournaments -- all four generators come on-line.

Power plant components include paralleling switchgear from International Power Systems, Barber-Colman synchronizers and a Square D programmable logic controller (PLC). "The Barber-Colman load sharing system, along with the voltage regulator cross current system, makes the control gear adjustments practically hands-off," Garrett said.

By selecting mechanical fuel injectors specifically sized for this application, Florida DD-A technicians have avoided problems of black smoke when the diesel engines are running at minimal loads, while providing adequate fuel at all expected power demands. Being able to integrate properly sized mechanical fuel injectors into the engines has proven to be a very effective means of preventing over-fueling and the smoke problems associated with it, according to Garrett.

"We are always concerned that the basic amenities are provided," said Kaboth, who also oversees the power plant. "While many of our visitors are a bit adventurous, they still do like their air conditioning. The generators continue humming away without interruption. We've taken their reliability for granted, and that is the sign of a successful power plant installation."

The generators' major prime power consumers include: Chub Cay Club resort and marina; the modest collection of town houses and ocean-front villas; the island's airport; a reverse osmosis (R/O) fresh water production system; and various communication systems. Discussions to add a fifth generator are underway as power demands increase on the island.

Florida DD-A technicians and Chub Cay maintenance personnel also follow a rigorous maintenance schedule. Garrett has trained the island's maintenance crew to carry out routine upkeep including changing the oil and oil filters every 100 hours, taking gen-set system readings (voltage, amperage, kilowatts, frequency, oil pressure and water temperature) every three hours, monitoring fuel system gauges, and changing the fuel filters.

Four times each year, Florida DD-A technicians visit Chub Cay Island to conduct several other advanced maintenance tasks, such as spraying the gen-sets' copper windings with an anti-corrosive solvent and applying an insulation coating, also to prevent corrosion. "It is a very corrosive atmosphere with all the salt-water -- the power plant is located so close to the ocean," said Garrett. "We will do anything we can to inhibit rust.