ies were dead or insufficiently charged.
• The fuel filter was clogged due to old or contaminated fuel.
All of these common issues can be eliminated with a regular generator maintenance routine performed by properly trained personnel. Facilities with qualified in-house technical
personnel often can perform required preventive maintenance on diesel generators. Other facility managers prefer to contract with a local service provider or power system distributor for regular maintenance service, especially if they have generators in multiple locations.
Following is a list of maintenance procedures that need to be performed on a regular basis. In addition to these checks, exercising the power system under load on a weekly or monthly basis ensures that the generator set and its system of controls and transfer switches is operating as designed.
Because of the durability of diesel engines, most maintenance is preventive in nature and consists of the following operations:
• General inspection
• Lubrication service
• Cooling system service
• Fuel system service
• Servicing and testing starting batteries
• Regular engine exercise
It is generally a good idea to establish and adhere to a schedule of maintenance /service based on the specific power application and the severity of the environment. For example, if the generator set will be used frequently or subjected to extreme operating conditions, the recommended service intervals should be shortened accordingly. Some of the factors that can require more frequent maintenance include:
• Using the diesel generator set for continuous duty (prime power)
• Extreme ambient temperatures
• Exposure to weather
• Exposure to salt water
• Exposure to dust, sand, or other airborne contaminates
If the generator set will be subjected to some or all of these extreme operating conditions, it is best to consult with the engine manufacturer to develop an appropriate maintenance schedule. The best way to keep track of maintenance intervals is to use the running-time meter on the generator set to keep an accurate log of all services performed. This log also will be important for warranty support. The Table shows a typical diesel engine maintenance schedule for generator sets.
When the generator set is running, operators need to be alert for mechanical problems that could create unsafe or hazardous conditions. Following are several areas that should be inspected frequently to maintain safe and reliable operation.
• Exhaust system: With the generator set operating, inspect the entire exhaust system, including the exhaust manifold, muffler, and exhaust pipe. Check for leaks at all connections, welds, gaskets, and joints — and make sure that the exhaust pipes are not heating surrounding areas excessively. Repair any leaks immediately. Check for excessive smoke upon starting: It can indicate possible performance and air quality issues that may require immediate attention.
• Fuel system: With the generator set operating, inspect the fuel supply lines, return lines, filters, and fittings for cracks or abrasions. Make sure the lines are not rubbing against anything that could cause an eventual failure. Repair any leaks or alter line routing to eliminate wear immediately.
• DC electrical system: Check the terminals on the starting batteries to make sure the connections are clean and tight. Loose or corroded connections create resistance, which can hinder starting.
• Engine: Monitor fluid levels, oil pressure, and coolant temperatures frequently. Most engine problems give an early warning. Look and listen for changes in engine performance, sound, or appearance that will indicate that service or repair is needed. Be alert for misfires, vibration, excessive exhaust smoke, decreases in power, or increases in oil or fuel consumption.
• Control system: Inspect the control system regularly, and make sure it is logging data properly during engine exercise. Be sure to return the control system back to normal automatic standby (AUTO) when testing and maintenance are completed.
Check the engine oil level when the engine is 