Generator Maintenance Guide

Reliable standby power starts with preventative maintenance.

A standby generator may run only occasionally, but it still needs regular inspection, exercising and scheduled servicing. Preventative maintenance helps identify starting, fuel, cooling, charging and control-system problems before the next mains failure.

1. Carry out routine visual inspections

Check the generator and surrounding area for oil, fuel or coolant leaks, damaged wiring, loose connections, blocked ventilation openings, unusual corrosion and controller warnings. The enclosure and access areas should remain clean and unobstructed.

2. Engine oil and filters

Engine oil condition and level should be checked and the oil and filters replaced at the applicable service interval. The correct oil grade and service schedule depend on the engine manufacturer, operating hours and site conditions.

3. Fuel system and diesel condition

Diesel generators depend on clean fuel. Fuel filters, water separation and signs of contamination should be checked during servicing. Generators that stand for long periods can still develop fuel-related problems even when operating hours are low.

4. Cooling system

Check coolant level and condition, radiator cleanliness, hoses, clamps, belts and airflow through the cooling system. Restricted airflow or a poorly maintained cooling system can cause overheating when the generator is placed under load.

5. Starting battery and charging system

The starting battery must be capable of cranking the engine when an outage occurs. Inspect battery condition, terminals and connections and confirm that the battery charger is operating correctly. A generator that does not start is often of no use regardless of its available output.

6. Air intake, belts and hoses

Inspect air filters, intake paths, drive belts and hoses for restriction, wear, cracking or deterioration. Replacement intervals vary by engine and operating environment.

7. Exercise automatic standby generators

Periodic test runs help confirm that the engine starts, the controller operates and the generator can reach normal voltage and frequency. Where appropriate, the complete AMF/ATS sequence should also be tested so the transfer system is not first proven during a real outage.

8. Load testing and operating condition

A generator can appear healthy while running with little or no load. Load testing can help verify generator performance under controlled load and can expose cooling, voltage, frequency or engine-performance issues that may not be visible during an unloaded run.

9. Keep service records

Record operating hours, service dates, parts replaced, test results and any recurring alarms or faults. Good records make future maintenance easier and help technicians understand the history of the generator.

10. Follow the correct service schedule

Service intervals are not identical for every generator. Engine model, hours, standby or prime operation, environmental conditions and manufacturer requirements all matter. Use the applicable engine and generator documentation rather than relying on one universal interval.