Five Maintenance Tips for a Mobile Generator

A mobile generator is often the most important piece of equipment on a jobsite — after all it’s what keeps the jobsite running. A well-maintained generator not only has the best chance at a long equipment life but also has greater potential for providing the performance and productivity necessary for getting a job done on time and on budget.

1. Stick to a Maintenance Schedule

A well-maintained generator is one that follows the manufacturer guidelines for scheduled maintenance. Daily, weekly and monthly generator maintenance includes visual inspection of machine components such as fluid levels and wiring and hose connections. Because generator use is measured in hours, significant service intervals typically occur at 500 hours, 1,000 hours and 2,000 hours and are repeated every 500 to 1,000 hours thereafter.

Recommended maintenance starting at 500 hours focuses on filter and fluid changes, including the engine oil, oil filter, fuel filter and air filter. A visual inspection should be conducted on areas that may need extra attention such as leaks, blocked air inlets and parts that may be susceptible to wear. A simple two-minute inspection could save one to two hours of downtime to replace a minor part.

“A frayed or cracked fan drive belt is an indication that it is wearing out. That’s an opportunity for preventive maintenance instead of waiting for it to fail and result in a machine shutdown,” says Todd Howe, global generator products manager, Doosan Portable Power.

2. Understand New Tier 4 Maintenance Requirements

New maintenance requirements resulting from Tier 4 compliance come into play at the 2,000-hour service interval. “Aftertreatment systems are part of the regular maintenance checklist now, so it’s important to become familiar with those requirements,” says Howe. These new requirements include replacing the crankcase ventilation (CCV) filter that prevents engine combustion byproducts and oil droplets from being emitted into the atmosphere from the CCV system. Howe says, “If it gets plugged up and not replaced, it can start to cause engine problems.” So it’s important to be aware of the additional element and the prescribed service intervals.

Tier 4-compliant engines that utilize diesel exhaust fluid (DEF) will also require attention at the 2,000-hour service interval to replace the DEF filter. The filter removes impurities that may exist in the DEF fluid or DEF tank before the fluid enters the aftertreatment system. Howe also recommends inspecting other emissions components that may be present depending on the engine model and system installed, such as the exhaust gas recirculation (EGR) system, diesel oxidation catalyst (DOC) or selective catalytic reduction (SCR). He says components should be inspected for buildup of carbon or soot. Components such as the EGR valve can be cleaned by hand, whereas for aftertreatment components, Howe advises to “put the machine on a load bank to remove the buildup.”

3. Adjust Maintenance to Environment

While 500-hour maintenance intervals are standard, Howe says those are maximum limits and should be scheduled more frequently for generators operating in harsh environments or challenging weather conditions. Dusty environments are particularly demanding on generators due to the volume of air flowing through the machine. Howe recommends inspecting the radiator fins for dust buildup and cleaning them with a pressure washer. “If dust gets wet, whether from a leak or other cause, it turns thick and clogs the radiator fins. When airflow can’t get through the system anymore, the machine is likely to overheat,” he says. Airflow can also be an issue in colder climates where snowfall can clog or freeze the air inlet grating. When a generator is operating in colder temperatures, a lightweight synthetic oil may be necessary to ensure adequate oil flow to vital engine components, while thicker oil grades are generally used to combat thinning oil in hot climates.

4. Maintenance Beyond the Engine

Howe says it’s important not to overlook maintenance areas that aren’t as easy to see. “The electrical system is a critical component of the generator but often neglected in maintenance practices,” he says. “There aren’t a lot of daily checklist activities, but periodic inspection can go a long way toward preventing catastrophic damage and downtime.”

Loose or worn wiring can lead to dangerous sparking or electrical short issues. Visually inspecting wiring from the alternator to the control panel can prevent common electrical problems by simply tightening a loose wire, insulating a rubbing hazard or bending a wire away from a sharp edge.

Howe suggests having a professional service technician complete preventive maintenance, including inspection of the control panel wiring and removal of exhaust blankets in order to tighten exhaust clamps during other significant maintenance tasks.

The trailer of a mobile generator is another often overlooked area from a maintenance perspective. Howe compares the necessary generator trailer maintenance to the routine service performed on a car or truck. “Check the tire pressure, rotate the tires regularly, maintain the braking system and ensure the trailer lighting is functioning properly,” he says. The trailer-to-vehicle lighting connector, tow hitch and jack stand may need special attention, as these pieces of equipment are exposed to excessive wear and tear on jobsites and in transport. Howe says it’s a good practice to replace these parts when worn or damaged to avoid a potential safety hazard.

5. Use Manufacturer Filters and Fluids

The primary purpose of routine maintenance is to extend the life of the generator. One of the best ways to ensure performance is to use genuine manufacturer aftermarket parts. “Those filters and fluids have been tested during the development of the machine,” says Howe. “We conduct thousands of hours of rigorous testing and have confidence that these filters and fluids will perform adequately and contribute to a long generator life.” Using off-brand filters and fluids introduces unknown variables that could affect not just machine performance, but also equipment warranty packages. When a generator has been properly maintained, the benefits are clear — longer machine life with greater reliability, performance and productivity.

Jamie Jackson is a technical writer for Two Rivers Marketing.