Beginner’s Guide to Generators: The Basics

Last Updated: September 16, 2022
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Generators make sure there is electricity wherever it is needed. Campsites often use quiet generators to power the occasional appliance or string of lights. They are useful for homeowners to have as backup power sources or for use with outdoor appliances. Those who own recreational vehicles provide the energy for their mobile homes.

Power generators have come a long way, and now you can buy a small, silent portable model that you can carry in one hand and use anywhere. They can run on a single tank of gas for up to 11 hours and weigh as little as 25 to 30 pounds. The largest of them can generate up to 6,000 watts of continuous power, making them ideal for home use. Some of them come equipped with USB ports for powering your smart devices.

Large portable generators powered by gas, propane, or a combination of the two have open frames with wheels that make them easy to transport. Even though their weight may be in the hundreds, they are balanced on the wheels so that a single person may move them with ease.

Some heavier, larger versions have wheels. Both home and industrial versions are available, with continuous power ratings ranging from the low 2000 watts to the high as 20,000 watts. These can be used to keep the lights on during a power outage or on a huge construction site. They find widespread application in community gatherings, sporting events, picnics, outdoor gatherings, backup power, the workplace, and recreational pursuits.

There are standby generators which can power your whole house in emergencies and can provide up to 24kW of power.

How Does a Generator Work?

Generators usually have four main components: a fueled motor that produces mechanical energy, a starter that uses electric and/or recoil starters, and an alternator that converts mechanical energy into electrical energy.

Generators burn fuel (e.g., gasoline, diesel) that is combusted inside a motor. The combustion creates mechanical energy that is transmitted to an alternator that transforms the mechanical energy into electrical energy. The electricity is then distributed to the electrical outlets on the generator, where you plug in your electrical cords.

Basic Parts of a generator

Main parts of a portable generator

Main parts of a portable generator
  • Fuel Tank
  • Fuel Valve
  • Choke
  • Air Filter
  • Recoil Starter
  • Oil Filler Cap
  • Control Panel

Main parts of a Standby generator

Main parts of a Standby generator
  • Oil Dipstick
  • Exhaust Enclosure
  • Air Filter Cover
  • Control Panel
  • Data Decal
  • Fuel Inlet
  • Fuel Regulator
  • Oil Filter
  • Composite Base
  • Battery Compartment

Types of Generators

There are three main types of generators that you can buy: portable, inverter, and standby. On-site, many different types of appliances can be powered by portable and inverter generators. Pick the right generator size by calculating the total wattage needed to power your devices and the power surge that will cause it to work.

As with the other generator types, standby generators provide backup power to electricity systems in homes, businesses, and factories. All generators are similar, and you need to follow the same safety measures in order to use them safely.

Determining Your Power Needs

It’s easy to ask yourself the most important question when you buy a generator: How much power will you need? Having a generator that will work for multiple appliances will help you determine exactly how much power you need.

If you know how you plan to use your generator, answering that question is easy. Manufacturers will provide you with the wattage that you’ll need to run your specific appliances and power tools. If you want to run several electronic devices at once from a generator, the total wattage that each device requires will be the minimum you need.

However, there are a few exceptions to this rule.

To start, there is a need to account for the spike power demand of appliances with motors. It’s important to note that the first few seconds of use, when the motor is starting up, have a significantly higher power demand. Therefore, all generators have what’s called a “surge rating,” or the maximum amount of power they can produce in a short period of time to get motor-driven appliances started.

The second caveat is that you shouldn’t always operate your generator at or near its maximum wattage. Instead, leave yourself some wiggle room in the power of your generator by adding the running wattages of all the appliances and gadgets you want to plug in.

The primary rationale for this is that constant operation at close to maximum power can significantly increase the generator’s engine wear and If you get as close to running your generator at its maximum power, your generator will be louder and will use more fuel.

Estimating Wattage Requirements

If you’re not sure how you’ll put your generator to use, if you plan to use it for a variety of tasks, if you don’t currently have access to all of the appliances you’ll need to run off of your generator, or if you plan to use it in the future, don’t fret. A generator’s power requirements can be estimated in a few different ways.

Numerous online calculators can help you determine the appropriate size generator for your home or recreational vehicle.

A 2,000-watt generator is enough for most home and outdoor uses, including powering modest appliances when camping or at a field project.

In the event of a blackout, a 3,000-4,000-watt generator will provide sufficient electricity to keep your home’s vital equipment operational. You may also use it to run a tiny air conditioner in your RV.

Generators with more than 10,000 watts of electricity are often used for longer power outages, larger homes, and construction sites.

Best Fuel for your Generator

Although gasoline is the most common fuel for generators, it is far from the only one.

The optimum fuel to use in your generator depends on its intended purpose and the fuels you have ready access to.

Dual fuel generators are the most popular variation on the traditional gasoline generator. Many of these generators allow you to switch between gasoline and propane without turning the engine off.

Propane, in contrast to gasoline, could be safely kept for a long time. As a result, if you’re concerned about a prolonged power outage at home, it makes for a great option.

Other than the higher purchase price, dual fuel generators have few drawbacks. A dual fuel generator could save you money in the long run if you use it with propane instead of gasoline.

The fuel flexibility of dual fuel generators is increased to tri fuel status by the addition of natural gas. You should expect a decrease in power production from your generator if you run it on natural gas rather than the other two fuels.

However, if your home is connected to a natural gas line, you can use that to fuel your generator during a blackout. As long as the buried lines aren’t broken, gas service can continue even if the power goes out.

Last but not least, diesel generators can operate reliably for thousands of hours with only occasional servicing. Diesel generators, however, are not as prevalent as gasoline generators because they are both noisy and more expensive.

Conveniences Modern Generators Offer

  • Wheels – Many lightweight choices are available, saving you the trouble of lifting a bulky piece of equipment.
  • There are handles on the side of the unit, so you can easily move it from one place to another without exerting too much physical effort.
  • Newer types often include convenient push-button or even remote-controlled starters in addition to the traditional pull-cord.
  • Automatic idle control (idle) helps generators run at a consistent RPM even while under severe loads. This lowers the noise of the machine and helps it use less gas.
  • Shutdown at low oil levels – When oil levels drop too low, the machine turns off automatically to protect the engine.
  • Some modern generators use noise-reducing mufflers or other noise-reducing technology, allowing them to operate in relative silence.
  • USB ports – In addition to standard electrical outlets, many new generators now feature USB ports for charging mobile devices and other electronics.

CARB Certification

An additional factor to consider when shopping for a generator is whether or not it has been approved for use in the state of California by the California Air Resources Board (CARB).

Not all generators are CARB-approved since the agency has stronger standards for engine emissions than the EPA.

Only CARB-approved generators can be sold in the Golden State.

Even if you don’t live in California, it’s always a good idea to see if something has been certified by the California Air Resources Board (CARB). CARB certification indicates that the generator in question is less polluting than its competitors.

Generator Maintenance

If maintained correctly, generators can run for decades. Changing the oil in your generator is the single most critical thing you can do to maintain it and keep it running smoothly. The engine oil in a generator should be replaced after first 30 hours of operation and again after 100 hours of use.

Moreover, you should never let old petrol sit in the tank. Damage to your engine is guaranteed if you use gas that has been sitting around for more than a few months.

You should thus drain the carburetor before putting the generator away for the winter or for an extended period. This may be accomplished with the push of a button on certain generators, while on others you’ll have to use up all the fuel.

The internal engine parts can be kept oiled by running the generator once a month, if at all possible.

When using your generator, there are a few more considerations you should be aware of.

The first step in refilling a generator is to wait until it has cooled down completely. The addition of gasoline to a hot generator poses a serious risk of explosion for both the operator and the machine.

Second, it’s important to remember that overusing your generator’s electricity or running it dry on a regular basis might ruin the motor. Take note of the wattage needs of the devices you intend to power with the generator, and plug in the ones with the highest surge needs first.

Finally, if your generator has an electric starting battery, make sure to maintain it charged. If that fails, use the generator’s pull-cord starter.

How Loud are Generators?

The new breed of inverter generators is helping to dispel the stereotype that generators are annoyingly noisy.

A typical inverter generator that generates between 2,000 and 3,000 watts of power often emits 50 dB of noise at 25% load, which is the same low level of noise as a conversation.

You should be aware that as you get closer to the generator’s maximum power output, the noise it makes will grow. Some inverter generators, which have a quieter starting noise of 50 dB, can go as loud as 70 dB when running at full throttle.

Use caution if running your generator late at night or near a campsite, as conventional and much larger generators can produce noise levels of up to 80 dBA.

Paralleling Generators

Connecting two or more of the same inverter generators in parallel will increase the total amount of power supplied by that outlet by that amount.

A parallel connection kit, typically offered by the maker of your inverter generators, will allow you to achieve this. Due to the integrated computers found in inverter generators, you must utilize a parallel connection kit designed for use with two generators from the same manufacturer.

The kit includes everything you need to hook up two generators in parallel via the main outlet panel. You can now power your sizable appliance by turning on both generators and plugging it into one of them.

Connecting a Generator to Your RV

If your generator has a 30-amp RV-ready outlet, connecting it to your RV is simple. These outlets are specifically intended to connect to your RV’s 30-amp inlet using any manufacturer’s transfer cord.

If your generator has a 120-volt/240-volt twist-lock outlet rather than an RV-ready port, you’ll need an adapter or a transfer cable built for this sort of outlet.

If your generator lacks one of them, you will be unable to connect directly to your RV’s 30-amp input. If you want to power your RV’s appliances with 120-volts, you’ll need to plug them into the generator’s

Connecting a Generator to Your Home

Portable generators can power your home’s electronics by simply plugging in an extension cord from each device. Although this is a quick, cheap, and easy fix, it can be inconvenient during longer or more regular power outages.

A transfer switch is used to connect a generator to the electrical grid so that it can power a dwelling. These can be pricey, and you might require an electrician to plug it into your existing circuit breaker if you don’t know what you’re doing.

Simply connect the 120-volt/240-volt outlet on your generator to the transfer switch you have already installed.

How Long Will a Generator Run on A Full Tank of Gas?

Due to differences in fuel tank capacity and engine efficiency, generators have widely varying run times.

Generators estimated running times often range from a few hours to 15 hours or more, with most estimates based on a 1/4 or 1/2 power load.

Choosing a generator based on its runtime is crucial if you intend to use it continuously or for long stretches of time. It’s important to remember that the generator’s run time will vary depending on how closest you run it to its rated power output.


You can use a generator to keep your home going during a blackout, to power your recreational vehicle or camping trip, or to provide a source of energy for construction sites or special events.

Keeping all these potential applications in mind, it’s crucial to pick a generator that’s well-suited to your demands and flexible enough to accommodate future needs.

Check out our in-depth shopping guides for additional details on the various generator types and recommendations.

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Thornton M. School

I am a mechanical engineer with years of experience working on Internal combustion engine and fixing electrical and mechanical systems, generators, transfer switches, and equipment related to storm water and sewage pumping stations.