If you put too much load on a generator then the circuits will trip and cut off the power supply from the generator to avoid damaging the generator.
However if you overloaded the generator and it didn't have any breakers then the generators windings would burn up and the engine would also bog down.
The amount of hours a generator will last depends on the type of generator.
Portable generators last between 1000 to 2000 hours or between 10 to 20 years if you run the generator on average of 100 hours per year.
However some portable generators may last longer.
Other heavier duty generators such as permanently installed backup generators with diesel engines can last several thousands of hours under constant use.
It's unlikely that a diesel generator engine would wear out if used only for backup.
If your generator is a gasoline or diesel generator and you have to refill the fuel tank then you should turn the generator off while you're refueling it.
If you leave the generator running while refueling it could start a fire if you spill the gasoline or diesel fuel on the exhaust.
It's best to shut the generator off for around 30 minutes, refuel and check the oil as well.
To ensure proper operation and keep the generator exercised you should start your generator at least once or twice per month.
Start your generator at least once per month and run a load on it for a few hours.
This keeps the fuel flowing through the engine and also ensures the engine is running properly and stays lubricated.
Also it keeps the generator windings warmed up and free of moisture.
The common problems of generators are low batteries, dead batteries, bad fuel, clogged carburetors etc.
Other common problems of generators include.
Battery Malfunction. There are several things that can cause your battery to fail.
Fuel, Coolant, or Oil Leaks. Fuel leaks often happen due to an issue with the pump system.
Low Coolant. Coolant is what keeps your engine from overheating.
Air in Fuel System.
You do need to break in a new generator.
If the generator is new it's important to break in the generator and engine.
Breaking in a generator properly prolongs the life of the engine, as well as other components, as they can be affected by outputs from an improperly broken in engine.
Your new generator needs to be broken in just as you would any other new or refurbished engine.
When you break in a generator engine, you ensure the pistons and rings within the engine wear grooves into the chamber’s walls.
This allows oil to properly lubricate these components every time the generator runs and keeps byproducts from the combustion process from escaping the chamber.
Over time the generator break-in procedures change, due to changing engine technology.
To ensure your generator engine is properly broken in, refer to your owners’ manual.
Each generator manufacturer has specific break-in guidelines for their engines.
Before breaking in any generator, it’s essential to fill the generators engines oil reservoir.
You will also need to change the oil during the break-in period, referring to your owners’ manual for specific time frames.
This is because as the pistons and rings wear into the engine’s walls, small pieces of metal will flake off into the oil.
It’s important to flush these pieces out of your generator by frequently changing the oil.
Using the correct fuel, let the generator run without a load for as long as the manual instructs.
For small, gas-powered portable generators, this may be an hour or more.
For large diesel generators, this is likely only as long as it takes to test installation.
Then, run your generator under a heavy load for as many as 100 hours.
The exact capacity and duration will be included in the manufacturer’s guidelines.
Under use during break-in, as well as throughout your generator’s life, causes a buildup of oil, soot and other contaminants throughout the generator, especially in diesel-powered generators.
As the break-in continues, and up until it reaches 100 or more hours of use, your engine will become more efficient.