Starting Watts Versus Running Watts

Over the past few weeks here at ToughAssTools we have been focusing on portable and standby generators for home and commercial use. That’s how we work around here. We find a specific type of tool and then read, learn, and write everything we can about it. Today, with generators, we are going to focus on what’s known as Starting Watts and Running Watts. If you already own a generator or are familiar with the term already then this article may not be for you. However, if you are in the research stage of your purchase then I highly recommend you keep reading to ensure that you get a firm grasp and understanding on the differences between these two measurements. Knowing these two measurements and how they can affect your generator are crucial.

First let’s start with that all generators, rather they be portable or standby, have the amount of power that they can provide measured in watts. Watts are a unit of measurement for power and are used to quantify the rate of energy that is transferred. The higher the number the more power or energy is transferred. Appliances, computers, phone chargers, or anything else that you plug into the wall will have a wattage rating. On some of the larger appliances like refrigerators or air conditioners the watts will be right on the label. However, with smaller things it may not be as obvious. If you were to look at a toaster for example, you may only find amps and volts. Nothing to worry about though as these two numbers can easily be transferred over to a watts. All you have to do is take the amps multiplied by the volts. You then have your watts. Measuring how many watts you need is a key step when figuring out what size generator you need.

Here’s the thing though, it is not just as simple as adding up all of the watts of each appliance. No, you also need to take into consideration what’s known as staring watts. Most appliances, especially larger ones like your refrigerators and air conditioners, will have two different wattage ratings. There will be starting watts and a running watts. Running watts are what we discussed above. These are the required watts to continuously run the appliance. (These watts are also known as rated or continuous watts.) Most of the time when you are looking at a toaster or coffee maker you will only find the running watts. This is also the wattage measurement that most folks are used to.

It is when we get into the larger appliances, especially ones with a motor, that we run into what’s known as Staring Watts. These watts, also known as Surge Watts, are the amount of power required to turn or start one of these larger appliances such as refrigerators, furnaces, air conditioners, and power tools. In order for these machines to start up they need a short and brief boost of power to get the motor going. This boost requires more watts then the standard running wattage. Once the motor has turned on the amount of watts required slowly goes down until it reaches the rated running watt level. Most of the time these extra watts are needed at the start of the appliance being turned on, but there are occasional instances where a compressor or motor will need to run during regular operation of the appliance. Again, starting watts will be used these scenarios as well. Starting watts are only meant to be used for a very short period of time. (Just a few seconds at most.) If you try to run numerous applications and you exceed the running watts but are still within the starting watts you will still overload your system. For more information on exactly what sized generator you should purchase please click here to be taken to our Generator Sizing Guide.

Starting watts are what’s known as maximum watts. When purchasing a generator you should pay very close attention to what the maximum watts of the generator is and the running watts. The worst thing you can do is purchase a generator, get it setup, and then find that you don’t have enough power because you bought based off of running watts and not surge watts. When looking at generators you should be able to find the specific maximum starting watts and the running watts. If it is unclear or you cannot find it on the product either ask for help or move onto a different product. As an example, if we look at Westinghouse’s WGen7500 portable generator on Amazon by clicking here we can see that it’s running watts are seventy-five hundred and the starting or surge watts are at ninety-five hundred. This is a great example as it tells you right in the product description. I’m a big fan of making things easy.

Lastly, if you are planning to purchase a generator check out our Best Generator Article by clicking here and also our Generator Safety Guide by clicking here. Remember folks, it is always best to be safe then sorry. Generators are not toys and they can be very dangerous if not used correctly. Please note that this article is intended to give advice and informational value only. We here at ToughAssTools are not liable for any damage when it comes to using generators rather it be personal, injury, or property.

Thanks for reading,

Alec Johnson


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