Generator wattage confusion

A

Auto Doc's

Lawn Addict
I see this happening way to often with people buying not only the cheapest, but also underpowered generators.

The surge/startup wattage is not the full-time running wattage.

Of course, everyone and their brother advertises the highest wattage number to give the illusion that the units have more power than they can actually produce full time. It's same old story of playing number games in advertising.

They (manufacturers) are playing on the general public's ignorance. Most people understand voltage, and some vaguely comprehend amperage, but wattage is often a puzzle. Wattage is the most important factor to know when planning for the limitation of the generator being used.

My point of this is to advise people to read the "fine print" and for them do the needed math to determine what their generator can truly handle before blindly plugging in and flipping components on.

Along with that, people must know what their primary power needs for electrical power are, prioritize what is the most important and shut off the rest.

I'm not going to delve in the math or the elaborate way to figure out what a person's generator needs are. There are plenty guides for that online.

Here is one example: https://www.generatorsizer.com/generator-size-chart.html
 
As far as I know Generac is the only one that classifies their generators by running wattage and not surge wattage. So an GP8000 is actually 8000 watt with a 10K surge.

But you are right about people not knowing what they need or what is required to run a specific item. And sometimes the item that they want to run isn't forthcoming about what is takes to start it, because the item will list running wattage and not start wattage, which can be considerably higher.
 
Even using the specs some generator will simply not start up things with their ratings. Take my 26g air compressor. I was able to start it with no tank pressure but when it had 90 psi the motor just stalled and smoked. Had to replace the motor and drag the compressor out a standard 240v outlet. It was because shop did have electrical service at the time but I was digging a 150 ft trench to install the feeder line. Very fun to do it with a manual post hole digger. I had to know the previous installed electric, water, and gas lines. No water line but there was gas and electric lines.
 
ILENGINE said:
As far as I know Generac is the only one that classifies their generators by running wattage and not surge wattage. So an GP8000 is actually 8000 watt with a 10K surge.

But you are right about people not knowing what they need or what is required to run a specific item. And sometimes the item that they want to run isn't forthcoming about what is takes to start it, because the item will list running wattage and not start wattage, which can be considerably higher.
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Hello ILENGINE,

The Generac portable that I have setup for my house is 15KW running and surge rated at 22.5KW.
I consider those as honest numbers and that is one of the reasons I own a Generac.

Sadly though, I am starting to see the "numbers game" being played by some retail places who are advertising Generac brand generators. They like use the term "starting wattage" in large number font and most folks have no idea what that means in reality. Meanwhile the running wattage is shown in much smaller number font.
 
Checked Generac portables at the hardware box stores, and it looks like Menards is listing the running wattage first followed by the running on their descriptions. Lowes, and home depot is advertising on starting wattage followed by running wattage on Generac.

Rural king is listing their Champion generators by running wattage in the title but peak wattage in the detailed description, but Champion is basing their generators on peak wattage.
 
The word "peak" presents a challenge to some people to test a generator by overloading it on purpose.

I was looking around online, and most people selling Generac among other brands and they are advertising the startup/ surge/ peak wattage as the big selling point.

My point is why create confusion, just state what the running wattage is and let the startup wattage be a quiet bonus. In other words, "state the facts" and not the illusion?

From what I have learned over the years, the "startup/ surge/ peak wattage" is the point where the engine begins to stall or stops from being overworked/overtaxed by the generator head.

There are very few units on the market that have an oversized engine that can take much of any load above the running wattage before they begin losing RPM or stalling.
 
Auto Doc's said:
From what I have learned over the years, the "startup/ surge/ peak wattage" is the point where the engine begins to stall or stops from being overworked/overtaxed by the generator head.
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For what I see the surge/peak is the point were it either blows the breakers or lets the factory smoke out of the windings. On some generators is it easy to overload the system and burn up the commuter. On others you can't reach peak performance without blowing the breakers. Kind of hard to overload a 10K generator when all the outlets are 120 volt outlets are 15 amp rated and total is only 60 amp.
 
Hammermechanicman said:
Reminds me of shop vacs advertised as "5hp" that are 120v @10A.
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Yeah, 5HP equates to roughly 3728 Watts (Work)

120V @ 10A load equates to 1200 Watts which equals 1.6092 horsepower.

They must fudge on the motor (unloaded speed) RPM of the vacuum somehow.

I'm no engineer, but the advertising does not add up.
 
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