# Trying to modify a Generac GP3300 Need Electrician



## sgip2000 (Sep 24, 2012)

lhoage said:


> I own a Generac GP3300 portable generator. It has 1 120/240 30amp receptacle and 4 120v 14amp receptacles. Upon opening the cover I discovered two 14amp breakers.
> 
> I'm no electrician, but I'm smart enough to follow direction. So help me out DIYnosaurs.
> 
> ...


There's a good chance that half of those 120v receptacles are on one leg, the other half on the other leg. That would give you 28A total. It just depends on how it's all wired.


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## ritelec (Aug 30, 2009)

So you will rewire and protect it all at 20amp.
How will you make it create more?

3300 / 240 = 13.75


interesting unit.


20 amp 120 v duplex receptacles on the 14 amp.

looks like 20 amp 240v 4 wire receptacle but specs claim it's 30 amp?

I was thinking, get a 30 amp cap for the outlet into a 2 circuit enclosure to a 2 pole 20 breaker to a double duplex outlet.

but again. 13.75

sell it.
take the money and apply it toward what you want.


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## ritelec (Aug 30, 2009)

actually specs show 3300-5000 (20.8 amps) 
not sure how it's wired that it could run at 20 and the breakers are at 14?

Have you been having issues the way it is?

You could go nuts, and rewire, but why. was what $450 bucks

sell it or give it to someone as a present (or keep it) and get the one that suites you better.


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## lhoage (Jun 13, 2014)

Engine: .unitedpower.de.com/en/node/244 add www

Some Evaluation .arb.ca.gov/msprog/offroad/cert/eo/2014/sore/u-u-125-0088.pdf add www

It looks as if they have one breaker on red, and one on black. They both tie into the rv outlet, which then splits from the rv outlet to each receptacle, one black and one red.


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## ritelec (Aug 30, 2009)

yes..

at 14 amp.

protecting the generator for the way they designed it


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## lhoage (Jun 13, 2014)

So the two 14amp breakers split across the rv outlet don't give it 30 amps? (Roughly)


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## dmxtothemax (Oct 26, 2010)

lhoage said:


> from the breakers to the receptacles to carry the load if this even works. But what about the wiring from the generator to the breakers?


Is the second set of breakers in your panel ?

What loads are you likely to run of the genny ?

Are they 120v or 240v ?

Remember the set amount of power,
so at the higher voltage you get lower current.
3300/120 = 27.5A
3300/240 = 13.75A

Do you know what size the existing wires are ?


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## k_buz (Mar 22, 2012)

Why anyone would give any advice other than "sell it" or "live with it" is beyond me.


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## beenthere (Oct 11, 2008)

k_buz said:


> Why anyone would give any advice other than "sell it" or "live with it" is beyond me.


I think sometimes its in the nature of people to try and make something work in a manor it was never intended or design to do.


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## lhoage (Jun 13, 2014)

Gentlemen, this is why it is called "tinkering".

Ahem.

The wiring is 14g. There are two 14amp breakers. I won't be using anything except 120v


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## beenthere (Oct 11, 2008)

2-14amp circuits(drawing 14 amps at 120 volts) is 3360 watts. So no need to replace those breakers with 20 amp breakers.


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## circuitman (Aug 9, 2013)

if the generator is limted to 15 amps per leg, then this all you will get. changing the breaker & wire size will do no good.if anything it will lead to damage of the generator.:whistling2:


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## lhoage (Jun 13, 2014)

Well, what I wanted to accomplish is to have a single 20 amp breaker feeding a single receptacle. I would just change this out back to the two 14 amps depending on the work load.

It seems that the way this is designed is not possible. As you are saying, I'm getting 14 amps from the motor on each wire. Getting a thicker gauge wire won't help the issue, it will just transfer 14 amps on each leg through that thicker wire anyways.

I appreciate the help in this matter. I'm not an electrician clearly. I'm a metalworker. I was just trying to make something work by recognizing a pattern in the design.


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## stickboy1375 (Apr 28, 2012)

lhoage said:


> Well, what I wanted to accomplish is to have a single 20 amp breaker feeding a single receptacle. I would just change this out back to the two 14 amps depending on the work load.
> 
> It seems that the way this is designed is not possible. As you are saying, I'm getting 14 amps from the motor on each wire. Getting a thicker gauge wire won't help the issue, it will just transfer 14 amps on each leg through that thicker wire anyways.
> 
> I appreciate the help in this matter. I'm not an electrician clearly. I'm a metalworker. I was just trying to make something work by recognizing a pattern in the design.


If it was designed to be on a 20 amp breaker, it would have come with a 20 amp breaker..... if anything, make a temporary sub panel up and plug that into the 120/240v 30 amp receptacle...


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## micromind (Mar 9, 2008)

This generator is capable of producing 27.5 amps at 120 volts. 

It is essentially two 1650 watt 120 volt gens in one unit. Presently they are connected in series yielding either 14 amps at 240 volts or two separate 120 volt circuits at 14 amps each. 

There are 4 wires coming from the windings, each one is 14 amps at 120 volts. If they can be separated and connected in parallel, the result would be 27.5 amps at 120 volts. 

Most gens have all 4 wires coming from the stator, some splice two in the stator and bring out only 3. In order for this to work, all 4 wires need to be present. 

If so, it's fairly easy to reconnect them in parallel.

Rob


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## AandPDan (Mar 27, 2011)

/\ This

lot of the older Generac's used to be wired like this. There was a switch you would flip for either 120 or 120/240. In the 120 position you had full capacity as it would parallel the windings.


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