ting battery.
• Cleaning batteries: Keep the batteries clean by wiping them with a damp cloth whenever dirt appears excessive. If corrosion is present around the terminals, remove the battery cables and wash the terminals with a solution of baking soda and water (¼ lb baking soda to 1 quart of water). Be careful to prevent the solution from entering the battery cells, and flush the batteries with clean water when finished. After replacing the connections, coat the terminals with a light application of petroleum jelly.
• Checking specific gravity: In open-cell lead-acid batteries, use a battery hydrometer to check the specific gravity of the electrolyte in each battery cell. A fully charged battery will have a specific gravity of 1.260. Charge the battery if the specific gravity reading is below 1.215.
• Checking electrolyte level: In open-cell lead-acid batteries, check the level of the electrolyte at least every 200 hr of operation. If low, fill the battery cells to the bottom of the filler neck with distilled water.
Generator set exercise
Generator sets on continuous standby must be able to go from a cold start to being fully operational in a matter of seconds. This can impose a severe burden on engine parts. However, regular exercising keeps engine parts lubricated, prevents oxidation of electrical contacts, uses up fuel before it deteriorates, and, in general, helps provide reliable engine starting. Exercise the generator set at least once a month for a minimum of 30 min. loaded to no less than one-third of the nameplate rating. Periods of no-load operation should be held to a minimum because unburned fuel tends to accumulate in the exhaust system. Whenever possible, test the system with actual building loads in order to exercise the automatic transfer switches and verify performance under real-world conditions. If connecting to the normal load is not convenient for test purposes, the best engine performance and longevity will be obtained by connecting it to a load bank of at least one-third the nameplate rating. Be sure to return the generator control to AUTO at the conclusion of any maintenance.
The backup plan
Although the United States enjoys high levels of reliable electrical service, utility outages happen often enough to require mission-critical facilities to have standby power systems. Preventive maintenance for diesel engine generators plays a critical role in maximizing the reliability of these standby systems and reducing the severe financial and life-safety risks associated with the loss of power. Financial losses from just a single data center outage can cost upward of $2 million in lost revenue. Preventive maintenance also minimizes the need for repairs and reduces equipment life cycle costs. By following generally recognized diesel maintenance procedures and application-specific manufacturer recommendations, facilities can be assured that their standby power systems will start and run when needed.
Kovach is operations manager for Cummins Power Generation’s PowerCare maintenance program, Minneapolis. He can be reached at email@example.com.