Load bank testing should be required to ensure proper installation, adequate cooling at ambient temperature, sufficient fuel delivery, and proper load transfer in your generator. For best performance, load bank testing should be performed annually (for a minimum of two hours) for standby applications. During weekly exercises, the engine will not reach the manufacturer’s recommended operating temperatures. The National Fire Protection Association (NFPA 110) has established the standards for monthly maintenance and operation for standby generators that states, “Generators should be exercised monthly at 30 percent of the nameplate rating or loaded to the minimum engine exhaust temperature recommended by the engine manufacturer.
An exhaust gas temperature of 275 degrees Fahrenheit must be maintained to avoid wet stacking. Regular load banking is an important step in minimizing exhaust pollution. Wet stacking is common when diesel engines operate for extended periods of time with little or no load applied. To operate at peak efficiency, the engine must be able to provide the proper ratio of fuel and air and maintain the right temperature to burn that fuel completely. EPA requirements have resulted in dramatic improvements in engine design, while the use of electronic controls has resulted in increased performance.