It’s dinner time, the wind is blowing outside and then suddenly it’s dark. The power is out and your pot roast is in the oven with 20 minutes to go. Don’t panic! You have a 7500-watt generator to keep the oven going, the hot water flowing and the heat on during this unexpected power outage.
A 7500 watt generator is a great size for most homeowners. With a 7500-watt generator, you can power up most household appliances including your refrigerator, hot water heater, well pump, freezer, light, and oven, depending on the units you have. In this article we will show you how to calculate exactly what a 7,500 watt generator will run in your situation.
Just a quick side note: There is a new solar backup generator out that is amazingly powerful you may want to consider along with your gas generator. It is called the Titan Solar Generator. In the below video I test one out and plug a bunch of devices into it so you can get a feel for how much power it has and how many devices it will run. If you have ever considered a portable solar backup generator for your home, it might be worth you taking a few minutes to watch this video. You may also want to see my related article “Titan Solar Generator – My Review!”
Okay now back to our main topic, the 7500-watt generator. In this article I am going over how to choose a generator, determining the energy load you need, how many appliances a 7500 watt generator will run, and a some general safety tips to remember. I have a table of contents with links below so that you can skip down and read the sections you want to read first.
Table Of Contents:
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Choosing a Generator
If you are in the market for a generator, you may have noticed there are a variety of different sizes and wattages available on the market today. It’s overwhelming how many configurations there are when it comes to generators. Let’s get into the basics of generators to help you narrow down your choice.
Generators are a backup power source for your home. You can have it hardwired into your home to automatically kick in when the power goes out, or you can have an electrician patch in a plugin for the generator that you physically turn on when the lights go out.
Having the generator hardwired into your house typically is more expensive. Hiring an electrician to safely hardwire or provide a plugin for your generator is the best way to make sure the wiring is done safely and correctly. Don’t try to do this yourself- a wrong wire or plug can cause a house fire or carbon monoxide poisoning. It’s just not worth it. Ask your electrician about a transfer switch on your electrical panel to make plugging in a generator easy and safe during an emergency!
A generator is sold based on wattage. A 7500-watt generator means that it can safely power appliances and other power need that total up to 7500 watts. The higher the watts, the more appliances, tools, and lights the generator can power. The physical size of the generator often correlates with the energy load it can handle. The more watts the bigger the generator. The smaller the watt load, the smaller the generator. You get the idea.
A 7500-watt generator is a popular choice for homeowners because it’s not too big and it provides just enough power for the essentials: keeping food cold, hot water, flushing toilets if you are on a well, taking hot showers and staying warm.
The best way to determine what size generator you need is to add up the wattage of all the appliances, lights and other power needs. The total of your power needs will determine what size generator you will need. The more power you need, the more expensive the generator.
A 7500-watt generator will cost you a couple thousand dollars. It’s an investment, but it can be a lifesaving tool as well. If the power goes out in the middle of January in Minnesota, I bet you aren’t going to be thinking about how much that generator cost you. You’re just going to be happy you have a way to keep your family warm.
Determining Energy Load
A 7500-watt generator is a great choice to run the basic appliances and a few extras, like a toaster, coffee maker, and blender. Although, I’ll be the first to admit I don’t really see powering a coffee maker as an extra. I think of it more like a need! But, that’s just me. To determine if this is the right generator for you, first take inventory of all the appliances, heaters and pumps you can’t live without.
You can find the true wattage of an appliance on the appliance itself or in a manual. When in doubt, contact a professional electrician to determine the wattage for you. This is important. If you overload the generator with too much wattage, the generator could overheat and wear down quicker. Overloading a generator could also damage wiring in your home and make it more difficult to get power to your appliances. Don’t overload your generator! You may need to buy another one if you do. Overloading a generator greatly reduces its lifespan.
There are two numbers you need to take into consideration when determining how many appliances you can power on a 7500-watt generator. There’s the running wattage and the startup wattage. The running wattage is how much power is required to run the appliance.
The startup wattage is how much power is required when you turn on an appliance, pump or furnace. The running wattage and the startup wattage are not always the same. You need to consider the startup wattage when determining the total power load for a particular appliance.
Let’s say you have an entire freezer full of meat, berries and other yummy food and the power is out. The power company expects to have power restored in the next five days. It’s the middle of summer and you can’t risk losing all that food. So, you turn on your trusty generator and power it up.
How much wattage does the freezer need and can I turn on my refrigerator too? Let’s say the running wattage of your freezer is 720. But, to start the freezer it needs more power. In fact, the startup wattage is 1890 for the freezer. So, this is how much total wattage is needed to start your freezer.
Walk through your home and make a list of all the appliances, pumps and heaters you need to comfortably weather your next power outage. Write down the running wattage and startup wattage of each appliance and add up all the numbers. You’ll be surprised at how many appliances you can run on a 7500-watt generator.
How Many Appliances
The Basic Calculation: The simplest way to calculate this is by adding the amount of watts each device you plug into it draws, compared to what the generator will handle. For example one 60 watt light bulb draws 60 watts of energy to run. (See my above video about the solar generator for an example of this.) This means at full capacity a 7,500 watt generator will power 125 60 watt light bulbs (7,500 / 60 = 125). Both my refrigerator and chest freezer draws between 12 and 40 watts each to run, and about 800 watts when starting. My space heater uses 1600 watts, so you want to avoid running things like electric heating devices (space heaters, electric oven, hair dryers etc.).
So to calculate what size generator you will need, simply add up the watt usage all of the devices you will be wanting to run (your emergency necessities) and plan accordingly. A good rule of thumb says that you should never operate a generator at its maximum power output for more than 30 minutes. This is why a generator’s rated power is usually a more reliable measure of generator power. Rated power is the power that a generator can produce for longer periods of time, which is typically no more than 90% of its maximum power.
Also remember that the more load you put on the generator, the more fuel it will consume. So in an emergency if you have limited fuel you will want to conserve.
For most homes, if you avoid things that produce electric heat, you can easily run all the necessary appliances with a 7500-watt generator. You may not be able to run everything at the same time (again you can calculate this by adding up the watts as described above). You may need to unplug some appliances to run others, depending on how much power those appliances you.
Another thing to remember is starting wattage. Some devices use more watts to start running than they do once they get going. So you would want to allow enough room for the starting wattage of the different devices when you do your calculation, so that you do not overload your generator. Once the big items are running, if you have to you can then turn on other smaller items.
Example Scenarios: Let’s run through a couple different configurations to show you how many appliances you can run with a 7500-watt generator. You can also easily do the research and crunch the numbers for your specific needs. Most power companies will offer wattage information about appliances and generator safety tips as well.
Okay. Let’s get started. When the power goes out you are going to want lights, refrigeration, freezer, water heater, well pump and a way to make food. Those are pretty much the basics. Let’s start with these appliances and see how much power they need to operate.
Refrigerator: A typical refrigerator needs 132-192 watts to run (mine is smaller than normal), but needs between 800 to 1200 watts to start it. If you have a separate freezer, it will be about the same.
Water Heater: An electric water heater element will use between 1,100 and 4,500 watts depending on weather the element is 120 or 240 volts. I could not find how many watts they take to start them. A natural gas water heater takes about 1,500 watts to start the unit, and around 500 or so watts to run.
Furnace: A typical home gas furnace needs between about 500 to 2,400 watts to start, and between about 300 to 900 watts to run, depending on the horsepower of the unit. An electric heat furnace takes between 10,000 to 50,000 watts to run, depending on its size.
Well Pump: A well pump only uses about 150 watts of power; however, it takes a whole lot of power to start it up. In fact, according to my local power company, it takes 1950 watts to start the pump. Yikes, that’s a lot of power. You can see how easily the watts add up.
Electric Oven: A typical modern electric oven can use between 1000 to 5000 watts, with an average using around 2400 watts on medium to high heat.
When determining what to power during an emergency, think about needs versus wants. You need water, food and a warm place to live. Yes, I’d love to power on the television and watch reruns of Gilligan’s Island, but it’s a want, not a need. And I’m certainly not going to be giving up my hot water for a sitcom. Again, you can always turn off appliances and turn on other appliances for a one-time use.
You can change what you power throughout the day and night, depending on the weather and your needs. If you live in Arizona, you won’t need heat, you’ll need air conditioning. A room air conditioner uses 1412 watts. Central air conditioners require 5400 watts to run and 7200 watts to start. There goes your watt budget.
Here’s a quick guide of wattage use for basic appliances: microwave-100 running wattage, television-50 to 400 running wattage, coffee maker- 1200 running wattage, radio-225 running wattage, slow cooker- 250 running wattage, computer-300 running wattage, washing machine-1150 running wattage and 2200 startup wattage, blender-375 running wattage and 500 startup wattage, air source heat pump- 5400 running wattage and 7200 startup wattage. For more accurate numbers, check with the appliance manufacturer or a local electrician. Your local power company is also a great resource for determining wattage of your appliances.
With a 7500-watt generator, you can run a lot of smaller appliances or a few large appliances, heat and water pumps. Determine what is most important to you during an emergency and power those appliances and comforts accordingly. In general, a 7500-watt generator should get you through the next emergency comfortably. Don’t expect to live like you do when the power is on. You will need to make sacrifices, even when you have a generator. Focusing on powering what you need to survive and you will be just fine!
Now, that you have a generator you need to make sure you know how to safely use the generator. As I mentioned earlier, you need to have a transfer switch installed. A generator transfer switch at the base of your meter will protect the power from “back feeding” onto lines. When power back feeds, a current goes back into the electrical lines and it could seriously injure or even kill crews working to restore power.
Always hire an experienced electrician to safely install a transfer switch for your generator. Never plug a generator directly into an outlet in your home. This can also create back feeding, ruin your wiring and potentially cause a fire. Also never run your generator from within your garage, unless you have proper ventilation. If you design your garage correctly, and have professionals who know accepted safety standards, all things are possible.
When you have safely connected your generator to your home, start by plugging in the largest appliance first. From there, plug in appliances, lights and other needs one at a time. Remember, do your math first to avoid overloading the generator. Also, make sure you have the right extension cords. A three-prong extension cord works best for large appliances. When using a generator, make sure it is in a dry location protected from rain, snow, and other wet weather.
Never under any circumstances should you ever run a generator inside your home or garage! Generators use gasoline to operate. Gasoline creates toxic fumes like carbon monoxide that can be deadly. Never use a gasoline powered generator inside your home! Your life depends on it.
On that note, never BBQ inside either. I know this sounds obvious, but it seems like every year during a power outage people die from using BBQs or generators inside their homes. Don’t be a statistic. Use common sense when operating your generator!
I want to mention briefly that many people who read this article also ask about the best emergency foods that have a long shelf life. For this topic see my article “20 Foods With Long Shelf Lives For Long Term Storage“. Okay now lets get to the meat of this topic. Let’s start with a table of contents so that you can read this article in the order most important to you!
Related Articles: “Will I need a portable generator In An emergency?” and “What is the best home solar generator on the market?“