A diesel generator is the combination of a diesel engine with an electric generator (often an alternator) to generate electrical energy. This is a specific case of engine-generator. A diesel compression-ignition engine often is designed to run on fuel oil, but some types are adapted for other liquid fuels or natural gas.
They require less maintenance due to their durability, reliability and the sturdiness characteristic and also they are considered cheaper to operate due to the low fuels costs as compared to the other types of fuels such as gasoline and propane.
They can withstand heavy load for long hours and start off the power supply on full load within minutes and must be regularly maintained to ensure they provide quality power throughout their service life. The best generator maintenance practice is following the maintenance schedule provided by the manufacturer of the generator to ensure maximum service time for the generator and proper operation when it is called upon to provide power.
Having a well-designed and well-maintained standby power system is the best protection against utility power outages.For hospitals and other health-care facilities they can be life-threatening. For businesses like data centers, the outages can be enormously costly. Other critical facilities at risk include government offices, police departments, fire stations, airports, and water/sewage treatment plants.
The preventive maintenance tips for the diesel generator that guarantees uninterrupted power supply that is innocuous and consistent for all the needs intended for. They include the following aspects:
Diesel Generator Routine General Inspection
During the running of the diesel generator, the exhaust system, fuel system, DC electrical system and engine require close monitoring for any leaks that can cause hazardous occurrences. As with any internal combustion engine, proper maintenance is essential. According to Georgia Scott of Constant Power Solutions one of the leading Generator and Power Equipment Manufacturers in the UK, standard servicing and oil change times are recommended at 500hrs, however some applications may require shorter servicing times which is why after sales services should be top notch.
1. Lubrication Service
The engine oil must be checked while shutting down the generator at regular intervals using a dipstick. Allow the oil in the upper portions of the engine to drain back into the crankcase and follow the engine manufacturer’s recommendations for API oil classification and oil viscosity. Keep the oil level as near as possible to the full mark on the dipstick by adding the same quality and brand of oil.
The oil and filter must also be changed at acclaimed time intervals. Check with the engine manufacturer for procedures for draining the oil and replacing the oil filter and their disposal is to be done appropriately to avoid environmental damage or liability.
Nevertheless, it pays to use the most dependable, highest quality oils, lubricants and coolants to keep your engine working. Therefore, according to Jim Girard of Lubriplate from Newark NJ, in the US, it is highly advisable to purchase lubricants that comply with the Original Equipment Manufacturer’s (OEM) generic lubricant specifications.
2. Cooling System
Check the coolant level during shutdown periods at the specified interval. Remove the radiator cap after allowing the engine to cool, and, if necessary, add coolant until the level is about 3/4 in. Heavy-duty diesel engines require a balanced coolant mixture of water, antifreeze, and coolant additives. Inspect the exterior of the radiator for obstructions, and remove all dirt or foreign material with a soft brush or cloth with caution to avoid damaging the fins. If available, use low-pressure compressed air or a stream of water in the opposite direction of normal air flow to clean the radiator.
3. Fuel System
Diesel is subject to contamination and corrosion within a period of one year, and therefore regular generator set exercise is highly recommended to use up stored fuel before it degrades. The fuel filters should be drained at the designated intervals due to the water vapor that accumulates and condenses in the fuel tank.
Regular testing and fuel polishing may be required if the fuel is not used and replaced in three to six months. Preventive maintenance should include a regular general inspection that includes checking the coolant level, oil level, fuel system, and starting system. The charge-air cooler piping and hoses should be inspected regularly for leaks, holes, cracks,dirt and debris that may be blocking the fins or loose connections.
According to Marketing Department of the Italy-based Visa SpA one of the world’s leading gensets suppliers, dedicated to design, production, sales and rental of generating sets; some engines used in Stand-by generating set applications have had a few issues concerning diesel fuel.
“While the engine maintains its mechanical properties, it can give rise to problems related to the quality of diesel fuel. The chemical make-up of diesel fuel has changed in recent years; a certain percentage of biodiesel at low or high temperatures releases impurities, while a certain percentage of biodiesel at warm temperatures mixed with water (condensation) can be the cradle of bacterial proliferation. Besides, the reduction of Sulphur reduces lubrication, which eventually blocks the fuel-injection pumps.”
“Moreover, by purchasing a genset, it is important to know that a wide range of optional accessories are available that allow to extend maintenance intervals and ensure providing quality power throughout the genset’s life. In the mobile range for example, Visa SpA offers fuel water separator filters, giving the customers the reassurance required when engine failure is not an option, or the fuel tank inspection points.”
Ms. Clarizza Cortez of Adpower one of the leading providers of Diesel and Gas Generators in the Middle East and North Africa also mentions that, since the fuel quality is bad in most countries, they install Water Separator Fuel Filters and additional filtration system to protect the sensitive fuel injection system; and advise the customers to replace the elements on time to avoid such breakdowns.
4. Testing Batteries
Weak or undercharged starting batteries are a common cause of standby power system failures. The battery must be kept fully charged and well-maintained to avoid dwindling by regular testing and inspection to know the current status of the battery and avoid any start-up hitches of the generator. They must also be cleaned; and the specific gravity and electrolyte levels of the battery checked frequently.
• Testing batteries: Merely checking the output voltage of the batteries is not indicative of their ability to deliver adequate starting power. As batteries age, their internal resistance to current flow goes up, and the only accurate measure of terminal voltage must be done under load. On some generators, this indicative test is performed automatically each time the generator is started. On other generator sets, use a manual battery load tester to attest the condition of each starting 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, verify 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.
5. Routine Engine Exercise
Regular exercising keeps the engine parts lubricated and thwart oxidation of electrical contacts, uses up fuel before it deteriorate, and helps to provide reliable engine starting. Engine exercise is recommended to be executed at least once a month for a minimum of 30 min. loaded to no less than one-third of the nameplate rating.
Most importantly, when it comes to engine maintenance, according to Peter Whitfield of YorPower a leading independent UK diesel generator manufacturer, it is recommended to do inspections regularly because preventative maintenance is better than reactive maintenance. Nevertheless it is of utmost importance to follow the designated service procedure and intervals.
6. Keep your Diesel Generator Clean
Oil drips and other issues are easy to spot and take care of when the engine is nice and clean. Visual inspection can guarantee that hoses and belts are in good condition. Frequent checks can keep wasps and other nuisances from nesting in your equipment.
The more a generator is used and relied on, the more it needs to be taken care of. However, a generator set that is rarely used might not need a lot of care.
7. Exhaust system inspection
In case there are leaks along the exhaust line which usually occurs at the connection points, the welds and the gaskets; they should be repaired immediately by a qualified technician.
Nevertheless according to Ms. Arlene of Maverick Generators in South Africa, always make sure your units are serviced. Especially 24 hrs before using your generators. “For standby generators for example you need to have your units serviced 150hrs on average. However if the generator is used constantly the hours go up much quicker and in more regular intervals,” she adds.
Furthermore, according to Ryan Mason of Lister Petter a manufacturer of internal combustion engines from the UK, it is quite advantageous when you have maintenance kits for different service intervals.