CUC engines years overdue for maintenance

Each of the eight engines at the Commonwealth Utilities Corp.’s Power Plant 1 have run at least 10,000 hours over the recommended maintenance plan.

As of this month, engine one is in most need of an overhaul. It has run 61,019 over the advised timeframe for an overhaul. If it ran continuously for 24 hours a day, it would be nearly seven years past the recommended limit. However, the engine has been under maintenance since November 2006.

Engine eight, which recorded the lowest number of hours in excess, has run 10,276 hours, or, if ran continuously, it is more than a year overdue for a major overhaul. The engine is one of two currently operational at the power plant. The other running engine—engine six—is 48,394 hours over the guideline. That calculates to 5.5 years.

The numbers were listed in the utility agency’s stimulus grant fund application. Under funds provided by the American Recovery and Reinvestment Act of 2009, CUC is seeking $36 million to purchase three new engines producing seven megawatts each.

CUC sets an operating capacity that allows the engines to run but takes into consideration the need for maintenance, CUC executive director Antonio Muña said. For example, engine six and eight are not running at their maximum capacity of 13 megawatts.

“Engines six and eight are rated at 13 megawatts but, depending on the weather, if cooler, we can run 4.5, maybe 5 [megawatts],” he said. “But if the weather is hot then we’re looking at 4 to 4.5 [megawatts].”

This way, he added, the engines can continue to run.

“We’re keeping operation within certain limits to allow us to get production, but respect the fact that the engines, that the maintenance, has been deferred,” Muña said.

He said it’s important the employees and the engines themselves are safe.

Maintenance periods are set by the engines’ manufacturer in accordance with the results of a test bench performance of a test engine, according to a power production specialist. From this test, the manufacturer can predict that at a certain point, some engine components will reach their maximum usage and will need to be replaced. If this is not done, he said, the warranty—if there were one—would be voided because of a greater chance for future problems. The capacity will also decrease due to loose compression and higher operating temperatures.

The specialist said if delayed an overhaul is harder to accomplish and takes more time because more parts will have to be replaced.

Acquiring the necessary parts continues to be a struggle for CUC. According to the grant application, when the engines were installed in 1991, insufficient parts were stocked, and, because the engines are unique to the Pacific region, there are no parts available from other engines in CUC’s system or other nearby utilities.

“Further, access to spare parts is limited to Mitsubishi in Japan or Man B&W in Germany,” the application said. “Thus, CUC is captive to a very limited source of supply that is subject to non-competitive pricing from companies in distant locations.”

Likewise, the engines on Rota are not maintained according to any routine preventative maintenance plan schedule, according to the application. Peak demand is greater than the capacity of one unit, so taking either of the two offline for extended periods adversely affects power production.

Since at least 2005, the Rota deputy director has urged CUC to provide supplies for maintenance, but as of this month, no progress has been made, the application stated. CUC is relying on purchasing power from the Rota Hotel Resort that generates its own power.

A 1994 management audit report predicted such problems for the islands of Saipan and Rota, saying the practice of limiting maintenance funding jeopardizes the reliability of the equipment. If it is not corrected immediately, the report said, “CUC faces the possible loss of key generation units, particularly on the islands of Saipan and Rota.”

“CUC has found this prediction to be true,” the grant application said, “as this is one cause of the most recent crisis that has affected the basic health and infrastructure needs of the CNMI community.”