Figure 2: Continuous Runs in the PC25 Fleet

While mean time between forced outages is 2000 hours for the fleet, Figure 2 shows the fleet has experienced nearly 30 continuous runs greater than sue months and three continuous runs greater than one year. This experience indicates the PC25 A design has potential for development to higher levels of reliability. Failures in the PC25 fleet are associated with ancillary components or with control decisions. To date, with proper system operating conditions, no failures have originated in the high technology elements of the power plant. As the causes for these failures are identified, improvements are instituted. For example, the first ran of greater than one year was terminated by a broken fan belt In the PC25 A and B fleets, an improved fan belt was identified which alleviates the problem. The PC25 C design alleviates or eliminates many of the failure causes in the PC25 A design. Direct drive fans were incorporated in the PC25 C to eliminate the problem. Sticking valves are another cause of failure which has been alleviated in the PC25 C through use of higher torque valve actuators. A number of changes have been incorporated into the controller to avoid shutdown and to avoid conditions which stress the cell stack or other components.

PC25 Production

IFC manufactured 74 PC25 A and PC25 B power plants in a facility in Middletown, Connecticut That manufacturing experience and the smaller size of the PC25 C power plant provided the basis for a redesign of the manufacturing plant layout to improve material flow and production efficiency when the manufacturing operations were relocated to South Windsor, Connecticut.

Figure 3 shows IFC's new state-of-he-art 80,000 square foot production factory located at its South Windsor,Connecticut facility. The manufacturing processes employed were developed specifically for a low-cost, high-volume production of the PC25 C power plant, advantage was taken of the Model C's smaller size which allowed an increased use of subassemblies, directly insertable as complete units. Final manufacturing and assembly of the electric generating portion of the power plant - the fuel cell stack - is completely accomplished in this factory. The highly automated processes include robotic component handling and assembly of the PC25 200-kW cell stack. The cell component manufacturing lines are arranged in a modified "spoke" fashion to allow for individual manufacturing requirements of each of the cell parts while bringing them in a continuous flow to a central stacking elevator. This power section is assembled with components and subassemblies provided by suppliers to form a complete fuel cell power plant. Rigid acceptance tests are performed to specific quality control criteria on the cell stack assembly prior to its installation into the power plant and on the completed power plant prior to its delivery.

PC25 Product Support

A product support program was initiated even before the delivery of the first pre-production PC25 power plant to provide customers with the necessary expertise to install, operate and maintain their power plants and to provide customers with real-time technical back up. This provides ready identification and correction of any operating problems. A world-wide service network was put in place by ONSI and its international partners; Toshiba and CLC. The network provides around-the-clock response to customer needs through remote performance monitoring and diagnostics which maintains continuous surveillance of all power plant installations. There are presently over 100 power plants in the PC25 fleet located in 12 different countries around the world. The operation of each power plant, at the customer's option, is monitored on a daily basis. In addition, significant operating events automatically result in an annunciation and a data acquisition sequence at the monitoring center in South Windsor, Connecticut.


The results reported herein are based on efforts by many people at IFC, ONSI, our international partners; Toshiba and CLC, and the support personnel of many customers throughout the world.

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