# Harbor Freight Predator 4000W/3200W



## LeStonga (Jan 17, 2019)

Hey everyone! This is my first post and I hope you all can help me with a few questions I have about this generator since I read the entire manual that came with the generator and didn't find the answers to my questions.

First of all, the generator says not to exceed 26 Amps - which makes sense since 26A x 120V = 3120W, which is slightly under what the generator is rated for continuous use.

My first question is this - The generator has 2 GFCI receptacles (2 plugs per receptacle for a total of 4 plugs). Each receptacle has a label stating not to exceed 13A per receptacle. I also have a NEMA L14-30 Plug, that although is rated at 30A the sticker on the machine says not to exceed 13A as well, just like the other two GFCI receptacles.

I am assuming since each receptacle - the 2 GFCI and the 1 NEMA are rated at 13A maximum each, and the machine says not to exceed 26A total, I can only use 2 of the 3 receptacles at the same time, correct?

Now for a more advanced question - the NEMA plug says its 240/120v, so I am assuming it is 13A @ 120 and 6.5A @ 240, would that be correct? There is no switch to select between the 240 and 120 voltage. Is the NEMA switch pigtailed off of the other two GFCI receptacles/breakers to get the 240V?

Finally and most importantly - I want to use just the NEMA plug to be able to plug into a transfer switch to my house. I want to use the full 26A that my machine can output, but I want the full 26A to be put through the NEMA plug. However, as previously stated the machine says not to exceed 13A (although the receptacle is rated for 30A - I am assuming it has something to do with the 13A fuses wired to the NEMA plug). 

If the machine is pigtailed off of the other two GFCI outlets at 13A each is the NEMA plug actually 26A output? Or if it isnt can I remove the wiring from the GFCI receptacles and combine both of the wires to the NEMA plug?

I have requested a data sheet from harbor freight but have not yet heard back from them. 

Thanks in advance for all of your time and help!


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## tabora (Sep 6, 2018)

LeStonga said:


> I also have a NEMA L14-30 Plug, that although is rated at 30A the sticker on the machine says not to exceed 13A as well, just like the other two GFCI receptacles.


The L14-30 plug should support the entire output of the generator (3200W continuous/ 4000W surge @ 240V) as long as the 120V receptacles are not being used. The 13A Max label on the L14-30 is @ 240V.


LeStonga said:


> I am assuming since each receptacle - the 2 GFCI and the 1 NEMA are rated at 13A maximum each, and the machine says not to exceed 26A total, I can only use 2 of the 3 receptacles at the same time, correct?


You can use any combination of the receptacles, as long as the total current per hot leg doesn't exceed 13A at 120V continuous. One of the 120V receptacles is on the X hot leg and the other is on the Y hot leg.


LeStonga said:


> Finally and most importantly - I want to use just the NEMA plug to be able to plug into a transfer switch to my house. I want to use the full 26A that my machine can output, but I want the full 26A to be put through the NEMA plug. However, as previously stated the machine says not to exceed 13A (although the receptacle is rated for 30A - I am assuming it has something to do with the 13A fuses wired to the NEMA plug).


As said above, you should be able to pull the full capacity through the L14-30 as is: [email protected]= [email protected]= [email protected]


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## LeStonga (Jan 17, 2019)

tabora said:


> LeStonga said:
> 
> 
> > I also have a NEMA L14-30 Plug, that although is rated at 30A the sticker on the machine says not to exceed 13A as well, just like the other two GFCI receptacles.
> ...


Thank you for your super fast response and detailed information! Your'e the best!


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## LeStonga (Jan 17, 2019)

Does anyone know the minimum idle speed without load and maximum idle speed for this generator?


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## tabora (Sep 6, 2018)

LeStonga said:


> Does anyone know the minimum idle speed without load and maximum idle speed for this generator?


 Non-inverter 2-pole generators usually must run at 3600 RPM at all times to maintain voltage and frequency.

Generator Frequency (f) = Number of revolutions per minute of the engine (N) * Number of magnetic poles (P) / 120 

Conversely, P = 120*f/N 

Therefore, a 2-pole generator producing an output frequency of 60 Hz has an engine speed of 3,600 rpm.


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## LeStonga (Jan 17, 2019)

You are the man! I bet you can answer my final few questions - for the Nema L14-30 plug on the generator, which is rated at 120/240v 26 amp how exactly does this work? 

From my understanding it is combining the two individual 120v phases to make the 240v, correct? 

There is no switch on the generator to switch between 120 or 240, so is there a way to get 120v at 26 amps? 

I'm assuming this plug is made to only hookup to a transfer box to feed the main panel in the house? 

The reason I ask is if there is a time that I want to power something that takes more than the 13A that the duplex allows I was hoping to be able to plug into the Nema connector to get a few more amps. 

I do not know of anything that runs 120v at 26 amps . . . I'm just thinking out loud. 

I am also assuming that when using a transfer box it is splitting the 240v output from the generator to the two 120v bus bars at the box. Can you see any reason to try to run 120v at its max amperage through the nema plug? I guess some people who back-feed (I know it is not safe nor legal) in case of emergency may benefit from this?

I'm sorry to post so many questions, but my manual sucks and doesn't explain anything really and youtube and google searches have not come up with answers to my questions.

Thanks for your help!


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## tabora (Sep 6, 2018)

LeStonga said:


> From my understanding it is combining the two individual 120v phases to make the 240v, correct?


Yes, the two rotors in your generator each make a 120V leg and the two legs are *180 degrees out of phase *(see graph below). Combining them gives 240V, just like the two alternating leg buses in your house's service panel. Putting in a standard size double breaker (not those skinny double-half breakers) is always giving you two 120V legs, one on each half of the breaker. This is by design; it may help you visualize the situation by looking at a photo of a breaker panel with some of the breakers removed (see below).


LeStonga said:


> There is no switch on the generator to switch between 120 or 240, so is there a way to get 120v at 26 amps?


No, at least not that you can combine to feed a single 120V device. (Alternate answer: Yes, buy a bigger generator!) You are always getting 26 amps of continuous capacity, but as two separate 120V legs, each of which can carry a constant load of 13A.


LeStonga said:


> I'm assuming this plug is made to only hookup to a transfer box to feed the main panel in the house?


No, there are lots of things like welders and pumps and machine tools that are 240V and can plug directly into the L14 outlet. You can also get heavy duty extension cords that plug into it and have 4 outlets at the other end, 2 from each leg, just like the two duplex outlets on the generator itself.


LeStonga said:


> The reason I ask is if there is a time that I want to power something that takes more than the 13A that the duplex allows I was hoping to be able to plug into the Nema connector to get a few more amps. I do not know of anything that runs 120v at 26 amps . . . I'm just thinking out loud.


No, but there are lots of things that take 15-20A 120V to run, and that small generator simply can't support them. My big air compressor would be an example, since it needs a 20A 120V leg to start easily. I have a 3500W generator that can't start it; my 6000W generator could care less.


LeStonga said:


> I am also assuming that when using a transfer box it is splitting the 240v output from the generator to the two 120v bus bars at the box. Can you see any reason to try to run 120v at its max amperage through the nema plug? I guess some people who back-feed (I know it is not safe nor legal) in case of emergency may benefit from this?


Again, look at the photo. All generator inlets "backfeed" the two buses from a large capacity double breaker. What makes them legal is if that generator breaker is adjacent to the main breaker and has an interlock to prevent both breakers from being on simultaneously, or a transfer switch that automatically performs that physical separation function.


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## LeStonga (Jan 17, 2019)

Thank you for the quick and informative response! So in theory I can run - via the Nema L14-30 plug - 120v @ 13A per leg to each of the bus bars in my house to get 26A total output power? I just cannot combine the 120v legs to get 26A on one bus. I think I am understanding you correctly, right? I believe in a previous post you had told me that the 13A rating was if I was running at 240V so I am assuming if I wire the L14-30 into two seperate buses it will run as 120V at 13A on each bus because I am essentially splitting the different phases to each bus?


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## tabora (Sep 6, 2018)

LeStonga said:


> Thank you for the quick and informative response! So in theory I can run - via the Nema L14-30 plug - 120v @ 13A per leg to each of the bus bars in my house to get 26A total output power? I just cannot combine the 120v legs to get 26A on one bus. I think I am understanding you correctly, right? I believe in a previous post you had told me that the 13A rating was if I was running at 240V so I am assuming if I wire the L14-30 into two separate buses it will run as 120V at 13A on each bus because I am essentially splitting the different phases to each bus?


Pretty much correct, but you're not "splitting" the phases; they are already separate on the X & Y contacts of the L14 plug. You are just "connecting" the 4 contacts of the plug to the 4 buses of your service panel. Note that the neutral and ground buses are usually combined at a service entrance; they are floating (separate buses) at sub-panels and hopefully also at your generator. That's why your generator only needs a ground rod when running standalone. When plugged into a service panel the service ground is used.


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## LeStonga (Jan 17, 2019)

That's perfect! Thank you again for all of your time and help! It is all starting to come together now!


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