What happens when you overload your generator

What Happens If A Generator Is Overloaded?

Many people living in areas prone to power failure due to weather conditions like storms, hurricanes, extensive flooding, etc., may invest in a portable generator. Running a generator ensures that your daily life does not come to a standstill. You can still turn on the lights, more powerful generators can run a fridge and even power your AC. However, you’ll probably be looking to get something upwards of 5KVA to power most household luxuries.

Today, portable generators are a lot more powerful, affordable, and even smarter than ones manufactured several decades ago. Not only do they have built-in overload protection, but many come with a low oil indicator too. That said, as the owner of a portable generator, knowing exactly what happens when it is overloaded will save you from panicking.

Understanding Loads

When you’re buying a portable generator, you’ll run into a term like kVA (something we’ve used above). kVA is an abbreviation for Kilovolt-Ampere. So, every 1kVA is 1k volt-amperes. Electrical power in our homes is measured in watts. Watts in voltage x current measured every instant.

Now, most people may not know this, but many appliances like the air conditioners, refrigerators, and electric furnaces have starting and running watts. Usually, there are starting and running watts when an electric motor is involved.

When an appliance is initially started up, it needs significantly more power to get the motor running. That extra power then slowly dissipates, and the appliances just need to keep running.

Many homeowners may assume that they have overloaded their generator by turning on an appliance with a high starting wattage. It is an honest mistake, but that’s not what causes it to overload.

What are the causes of the overloading of generators?

As mentioned above, one of the most common ways in which portable generators are often overloaded is by exceeding its wattage limitations. Sure, many appliances with a motor will exceed the running watts, but starting watts are only for a second or two, after which the appliance switches to running watts. An overload often occurs when there are too many appliances plugged into the generator, and their total wattage exceeds that of what the generator can handle.

Most generators can only sustain a peak output for a short few minutes. After that short time has passed, the generator goes into overload mode, causing its circuit breaker to trip and turn off. If the generator does not have a circuit breaker (like ones a few decades old), then there is a chance that it will overheat and suddenly combust.

What Happens If You Put Too Much Load On A Generator?

Please keep in mind that starting watts aren’t meant to be sustained for a very long time. However, most generators available today will not combust because they became too hot. Though with older ones, you need to keep an eye on them.

Despite there not being a fire risk with many modern, well-built generators with circuit breakers, running a generator beyond its capacity can cause components to burn on. It can shorten the life of the generator significantly.

An overloaded generator could end up outputting intermittent power, which will damage your appliances. That’s why it is imperative that you keep an eye on the generator’s running wattage and never exceed it for the sake of safety and your investment in the generator.

No matter what happens, you shouldn’t allow the generator to exceed its maximum output wattage. It should not happen. The capacity you see printed on the generator is based on two things, the first it’s capacity to produce electricity via the alternator, and the second the engine’s power to drive the alternator.

How do you stop a generator from overloading?

As mentioned above, many generators come with circuit breakers that limit all excessive current. If the breaker trips, your generator will turn off. If your generator has a circuit breaker, it does not require that you monitor it closely. The circuit breaker will tolerate the starting wattage, but not past a few seconds.

The other way to prevent your portable generator from overloading is to only power designated appliances. For instance, most small portable generators up to 2kVA can power a couple of fans and LED lights. If anything, these will not trip the generator. If you have a generator that’s upwards of 5kVA, then appliances like a fridge or AC can easily be powered. However, it will depend on the wattage of your fridge and AC. You can use an online wattage calculator to figure out if your portable generator can handle them.

Some generators make strange noises when they are put under heavy loads. If you suddenly hear a strange noise because you turned on maybe a fan or the TV, it means your generator is under a load it can’t handle—time to turn that appliance off.

How do I know if my generator is overloaded?

If you have a circuit breaker installed like most modern generators that come with one built-in, overloading will cause it to turn off. However, if a circuit breaker isn’t installed, you’ll probably be able to tell that the generator is becoming excessively hot. Also, the noise may change as the engine is under more load than it can handle. Either way, turn off your generator to let it cool off and turn off excessive appliances.


When buying and using a portable generator, make sure to take note of its starting and running watts. Once you have the required figure, add around 30% so that you have some extra leeway. If you see that the generator is struggling to handle the load, is easily overloaded, or is becoming hot, then it’s time to unburden it or get a larger generator.

It is also worth mentioning that overloading your generator to failure frequently shortens its life and may cause some components to fail. So, make sure that you keep a close eye on everything to avoid the generator breaking down for times when you need it the most.