Exploring the Top Reasons Why Preventative Maintenance is Critical for Your Generator

Have you been servicing your genset as you should?
14 August, 2022 by
Exploring the Top Reasons Why Preventative Maintenance is Critical for Your Generator
T&T Power Group.

Recent extreme weather events in southern Ontario brought winds strong enough to uproot trees, rip the roofs off of homes and snap utility poles in half. And unfortunately, all climate models indicate that these instances of harsh weather conditions will only become increasingly frequent moving forward.

With that being said, if you have made the decision to invest in a standby generator, preventive and routine maintenance is critical to keep you from ending up in the dark - while also providing a host of other benefits for your gen-set (and your wallet).

Will your generator start when the utility power fails?


The only way to ensure your generator is ready to work when needed is to inspect the unit on a regular basis and record your observations in a logbook. It is recommended that a weekly visual inspection of the gen-set take place focusing on the following aspects of your gen-set:

  • Was the generator control panel found in AUTO?
  • Were there any alarms on the generator control panel?
  • Place generator control panel in MANUAL to inspect generator
  • Is the fuel level or pressure adequate if the power fails?
  • Is the coolant level sufficient to operate the generator?
  • Any leaks on the ground or hoses?
  • Are the starter connections tight and secure?
  • Are the battery connections tight, secure and clean without grease or corrosion?
  • Check engine oil level, fan belt wear and tension, and make sure block heater is warm
  • Check control panel integrity and ensure all indicator lamps are functioning
  • Check to ensure the generator output breaker is in the ON position
  • Inspect generator and automatic transfer switch room for obstructions and cleanliness
  • Before leaving the generator, check controller to make sure the gen-set is in AUTO.


 If you have any issues or questions with the weekly visual inspection, call your T&T Power Group service provider for answers at 800-221-3432.


While most generators are inspected weekly by in-house maintenance staff, more thorough inspections and service is usually completed by trained generator technicians.


During your monthly and semiannual generator inspections, a technician will take a look at aspects of your generator such as its fluid and oil levels, the status of the oil filters, the belts, connectors, hoses, lines, and any other appendages, as well as the control panel and the engine, the exhaust system, and more.

These checks also involve transferring some building load (30-40% of rated gen-set capacity) onto the generator to ensure the automatic transfer switch (ATS) and generator are functioning properly. It is recommended that any inspection or service conducted where the transfer switch is operated should be accompanied by a properly trained generator technician.

The technician will also clean parts when necessary, as any debris or dirt can potentially damage your generator. These routine checks and cleans help to ensure your generator stays running at top efficiency and performance.


 Regular generator servicing can save you from large repair bills, all while improving performance and extending useful life of asset.


Any mechanic will tell you that engines need to be worked frequently and do not respond well when sitting idle for long periods. For this reason, most gen-set controllers and automatic transfer switch controllers can be set to exercise on a weekly basis. Such an exercise regime will give maintenance staff advanced warning of any issues that could affect the generator operation and limit expensive service calls and repairs such as these:

1) Service call for no crank alarm on gen-set indicates the cranking batteries do not have enough voltage to start the generator. The Electrical Generating Systems Association (EGSA) recommends changing out cranking batteries every three years or when the battery capacity falls to 80% of manufacturers rating.

2) Generator controller not left in AUTO is a common service call issue when recent work was done on or around the generator or when the emergency button was not reset. As a safety precaution, generators must be placed in MANUAL to conduct service work so they do not start when you have your hands around dangerous moving parts.

3) Cooling system issues like worn belts and hoses, leaking gaskets, plugged thermostats and radiator fins are all signs of impending temperature problems that are easily found and reported to your service provider for an inexpensive repair rather than a middle of the night expensive service call.

4) Most industrial gen-sets are powered by diesel or natural gas. Over the past few years, diesel has been made with fewer additives allowing a faster breakdown and contamination of this fuel due to its organic nature. Diesel storage tanks always have condensation to deal with requiring regular inspections of the entire system. Natural gas (NG) has fewer issues, with the most common being low pressure. When NG gen-sets are first installed the gas pressure is regulated to provide enough pressure to comply with the manufacturer’s specifications. Often other appliances that use NG are added to the line which use the fuel in HVAC systems leading to low gas pressure.

5) Standby generators transfer building load onto the generator by means of an automatic transfer switch (ATS) when the ATS senses loss of utility power. Modern ATS controllers are microprocessors that maintain system settings, date and timing (exercise) functions by means of a coin type battery. If the power did not transfer during a recent power failure, this battery is one of the leading causes that should be checked every service interval. Other ATS issues resolved by regular maintenance are dirty or corroded contacts, stiff or sloppy mechanical action, loose wire connections and circuit board failures.

6) All generators have circuit breakers in line to protect equipment. Breakers have trip settings that need to be adjusted at installation or when loads have changed to avoid nuisance tripping. Reliable generator operation requires planned maintenance, like cleaning, adjusting, lubricating and testing. If the circuit breaker is not closed after maintenance, power will not be available in the event of a utility failure.

7) Every combustion engine needs to breathe air to burn fuel and provide power. Timing of opening and closing of intake/exhaust valves and a proper seal are critical to the gen-sets fuel economy and engine temperature. Valves left unadjusted fatigue, erode and crack over time. Debris from disintegrating valves will cause damage to the most expensive engine parts if left undiagnosed like, cylinder liners, cylinder heads, turbochargers and pistons. On new gen-sets valves should be adjusted during the first full service with oil change so the oil can be analyzed at a laboratory.

8) In most industrial or home applications, an alternator (generator end) provides power by taking the motive force supplied by the engine to turn a rotor inside a stator and produce electricity. Alternators are at the mercy of their environment and often get coated with dust, dirt and oil. Temperature fluctuations often cause condensation to form inside the alternator windings leading to corrosion which can lead to arcing to ground, a catastrophic failure. Regular cleaning and testing of the windings benefits the owner with a longer service life.

9) Lubricating oil is the life’s blood of a gen-set. Just like the human body, plaque forms on surfaces where buildups of carbon and corrosive damage occurs, leading to excessive bearing wear, crankshaft damage, wear surface seizure and other catastrophic engine failure scenarios. It is extremely important to change the oil on a regular basis. It does not matter if there are relatively few hours on the standby generator, oil accumulates and binds contaminants leading to a degradation of performance and risk of potential engine failure.

Since emergency standby generators frequently exercise or operate at much less than full load, they are inherently prone to wet stacking and carbon buildup due to an accumulation of lubricating oil and unburned fuel in the exhaust stack (referred to as wet stacking). Low level use of gen-sets causes carbon buildup in combustions chambers, injector nozzles, piston rings, turbos, exhausts and silencers. To deal with this type of issue, generator technicians bring along a resistive load bank to ramp up the generator to its full load rating for two hours to burn out the carbon and other waste products on an annual basis.

Gen-set owners are not the only people interested in your generator maintenance habits.


1) Know your warranty period and stipulations. Most standby generator builders will warranty certain types of use over a number of years or running hours, whichever comes first. It is in the owner’s best interest to have a qualified generator service technician inspect and service your gen-set a number of times in the warranty period to catch any operating deficiencies before they cost you the big bucks.

2) It is highly recommended and mandatory for some buildings in Ontario and the rest of Canada to follow the service inspection criteria in the CSA282 Emergency electrical power supply for buildings. Any building where life safety could be an issue is required to have a logbook documenting service by both on site maintenance staff and professional generator technicians. Inspections by local fire marshal’s require compliance with the CSA282 and the documentation they will be looking for is the logbook and generator reports by qualified technicians.

Insurance companies are very interested in generator maintenance records when a claim is made. Our team has witnessed many a chicken farmer lose hundreds of birds in less than an hour when the power fails on a hot summer afternoon, and the backup generator failed due to being poorly maintained. Good luck with that claim if you can’t provide generator maintenance documentation from a third party.


All in all, generators that aren’t maintained experience shorter lifespans, while their owners fall victim to costly repairs along the way.


Neglecting regular maintenance checks on your generator may save you some money in the short-term, however, without those checks your generator is more prone to eventually requiring costly repairs - and in the worst case, requiring a total replacement. At the end of the day, routine preventive maintenance will help to ensure that your generator continuously runs how it should, for as long as possible - and will help you to get the most out of your major investment.

T&T Power Group has been a generator service and maintenance specialist for over 40 years


Let us help you keep your generator in top shape for years. Request your service visit with our technician today.

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