How Do Generators Work?
Thursday June 19, 2025
A portable generator is a convenient way to safely produce your own power when the grid goes down, either due to natural or man-made causes. But how does a generator work? Whether you’re new to using a generator, or well-experienced, there are a few things you need to know to operate it safely.
➡️ How Does a Generator Work?
Before we dive deep into the specs and best practices for a home generator, it’s important to note that portable generators are not the same thing as home standby generators, which are machines that are permanently hooked up to your house. Home standby generators automatically kick on when the grid stops supplying power to your house, whereas a portable generator is smaller and requires more planning.
Portable generators convert mechanical energy into electrical energy, oftentimes relying on gas to kickstart the process (though you can also find diesel and propane units). Regardless, your generator has five primary parts: an internal combustion engine, an alternator, a starter, a fuel tank, and outlets.
➡️ Electrical Requirements
1) Size Matters: Size the generator correctly so that it meets the electrical loads you intend to power with some excess capacity built in.
2) Use a Transfer Switch: The safest way to use a portable generator for home power backup is to use it in conjunction with a manual transfer switch. The generator connects to the transfer switch with a thick, heavy-duty cable called a “genset cord,” which is plugged into an outlet receptacle installed on the outside of the house (that receptacle is officially known as a “power inlet box”). A cable on the inside of the house runs from the outlet to the transfer switch. Electricity from the generator runs through the genset cord, to the receptacle, through interior cable, to the transfer switch and its circuit breakers to the various circuits you need to power–safely.
3) Use a GFCI Transfer Switch on a GFCI Generator: The National Electrical Code (NEC) requires GFCI (ground fault circuit interrupter) outlets on dual-voltage generators (those that produce 120 and 240 volts).
4) Use Heavy-Duty Cords (Correctly): You can safely operate appliances plugged directly into the generator. You can power your refrigerator, power tools, and computers (for example) by running long extension cords to the generator. These cords should be heavy-duty and of a thick enough wire gauge to handle the current flowing through them; the cord’s packaging will tell you what electrical load it’s rated to supply. Next, the cords should be rated for exterior use.
There is a correct sequence to power a load through an extension cord. Start the generator, and plug the cords into it. Then go inside and plug the loads into the extension cord. Do the opposite when it’s time to disconnect the loads. Unplug the loads from the generator, then go outside and unplug the cords, and turn the generator off.
5) Understand When and How to Use a Ground Rod: Don’t connect the generator to a ground rod when you plug loads directly into the generator by extension cords. To restate that: If you plug a heavy-duty extension cord into the generator and connect that to an appliance, power tool, or device, skip the ground rod.
➡️ Carbon Monoxide Safety
Like most small-engine machines, generators produce large amounts of carbon monoxide (CO). You’ve heard us say it before, but we’ll say it again: Never, under any circumstances, operate a generator in a garage, utility building, or shed (even with the door open), in the basement, or in any manner in which carbon monoxide can collect to the point where it becomes deadly.
Furthermore, point the generator’s exhaust away from the house.
• What Is Carbon Monoxide Poisoning?
Finally, many generators are equipped with CO detectors that will shut the machine down before CO builds up to the point where it becomes deadly. Although a generator thus equipped is a little more expensive than one without the technology, it’s still a good idea.
➡️ Fuel Quality and Safety
Don’t refuel a hot generator, don’t refuel it in the presence of a heater or other hot object (like a barbecue grill) that’s running nearby, and don’t store fuel containers near the generator. Be particularly mindful that the muffler on a generator can be hot enough to melt plastic.
➡️ Weather Safety
People have gotten creative building all kinds of cobbled-together shelters to protect their generator from wind, rain, and snow. Assuming that they don’t get blown down or collapse, that’s all fine, but keep a five-foot air space from the generator to surrounding surfaces; this prevents overheating the generator and reduces the risk of fire.
➡️ Operational Safety: Make a Test Run
The only way to ensure that your system operates properly is to thoroughly test run it immediately after it is set up. Don’t wait for an emergency, take a full test run while everything is normal and you are calm.
Contact us today to help you with all of your generator needs!
Contact us today to help you with all of your generator needs!
About Chapple Electric
Chapple Electric LLC is a second generation, family owned company that was started in 1978 by our founder, Charles Chapple. What started out as a small 2 man operation doing residential electrical repairs has now become a large commercial, residential and industrial electrical contracting company, which operates with several crews across the state of Michigan. From the very beginning, complete customer satisfaction has been the cornerstone of our success and longevity.Chapple Electric is one of Michigan's most trusted names in electrical repairs, installation and upgrades. Since 1978, we have been committed to excellence in design, workmanship, competitive pricing and customer service.
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Why Choose Chapple Electric?
At Chapple Electric, we know that the electrical system is the lifeblood of any structure. How that system functions can either enhance or hamper the comfort and productivity of its occupants. In order for the electrical system to function properly, it must be designed and tailored to the owner's needs and usage, correctly installed and be backed by a service team available 24 hours a day 7 days a week.To ensure this happens, you need to work with a company that's on top of the trade. One that knows electrical systems inside and out, and is in step with all the current codes and standards for the profession as well as the latest in technological and product advances. A company that has the professional staff and experience to design, build, deliver, install and maintain a system that's done right. Read More
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- 11220 Torrey Road
- Fenton, MI 48430
- Phone: 810-691-6921