# Pure Sine Wave Inverter generators



## redcentinela (Feb 26, 2015)

Hi everyone and thanks for letting me be part of this forum.

I have a china made XG-SF5600 Pure Sine Wave Generator.

Here are the output voltage my inverter genset is capable of according with factory specs:
Rated AC Voltage 110/220/230/240V.

This genset has no dual voltage outlets ( 110V and 220V like the Honda ). This china inverter generators come either 110V or 220V. My question is how the factory makes them produce 110v or 220V. I think it is the inverter module that does that convertion since the generator head is capable of producing 3 phase voltages ranging around 400V AC I think. 

Since this inverter genset is capable of producing voltages from 110 to 220v, what should I change in order to make it 220v.

Any ideas ?


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## gardner (Oct 21, 2014)

It would most likely be different internal parts -- probably different inductors in the internal step-up circuits. Not a user changeover.

Even if it generated 220, that would not be a north-american style split phase 220 with neutral in the centre. It would a rest-of-world 220 hot + neutral, which no north american appliance is designed for.

Can you explain why you want 220V from a generator designed for 110?


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## KRE (Nov 29, 2011)

gardner said:


> It would most likely be different internal parts -- probably different inductors in the internal step-up circuits. Not a user changeover.
> 
> Even if it generated 220, that would not be a north-american style split phase 220 with neutral in the centre. It would a rest-of-world 220 hot + neutral, which no north american appliance is designed for.
> 
> Can you explain why you want 220V from a generator designed for 110?


 That is not correct. First in the US it's 120/240 Vac which in reality is quickly becoming 125/250vac. In lands across the ponds they are still using 220/380 Vac but that is mostly 50 hertz.
On (US)240Vac only loads one does not need a neutral as the two 120Vac legs are 180* out of phase which is how you achieve 240Vac. If you running a 240/416 wired unit all you need is one hot leg and the neutral to power the device. The key word is RMS Voltage potential. You can powder a 240Vac load with one leg from a 277/480 Vac unit. One leg to neutral is 277Vac but if you use a buck/boost transformer wire correctly it put the neutral out of phase just enough where the max RMS voltage is 240Vac. You can use the same transformer to step up the 240 to 277 + or - as you need. 

RMS Voltage potential, is the key phrase.


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## KRE (Nov 29, 2011)

redcentinela said:


> Hi everyone and thanks for letting me be part of this forum.
> 
> I have a china made XG-SF5600 Pure Sine Wave Generator.
> 
> ...


Read the paperwork that came with it. It should show the required change, my guess would be a jumper has to be moved. Is this a 50 or 60 hertz machine?


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## redcentinela (Feb 26, 2015)

I plan to use it in my house. By the way, I opened this genset and found out that it has two inverter modules inside, each one aupply voltage to the outlets independently. (Each inverter module supply 120 v to each receptacle). 

Any way to rewire in order to have 240v since it has separate inverter modules?


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## KRE (Nov 29, 2011)

redcentinela said:


> I plan to use it in my house. By the way, I opened this genset and found out that it has two inverter modules inside, each one aupply voltage to the outlets independently. (Each inverter module supply 120 v to each receptacle).
> 
> Any way to rewire in order to have 240v since it has separate inverter modules?


 I doubt it but, post the wiring diagram if you have one and I can tell you one way or the other. You can take a volt meter and test the 2 hot legs if they are in-phase you will read nothing, if 180* out of phase it will read 240Vac.


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## redcentinela (Feb 26, 2015)

Hi KRE.

Nope, there is no wiring diagram. As I told, this generator has 2 inverter modules, each one generates 120v from the connector 
coming directly from each inverter. Each connector has 1 white cable and 1 black cable. There is where I get the 120v.

Here is a wiring diagram made by me showing you how it is wired to provide 120v to each outlet. Hope it help to clarify things.


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## redcentinela (Feb 26, 2015)

Dont remember if I measure the two white cable or the two black cables for voltage. I measured one of those and had 0 voltage. I' ll check and let you know.


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## aandpdan (Oct 8, 2012)

Looking at your schematic, the inverters are in parallel to increase the output capacity. We know both inverters are synchronized for phase.

You could wire it as shown here. The inverters would now be in series and it would give you the higher output voltage.

You will need to watch the load however. Wired in series you now only have half the output capacity. If it was 5kw before it is now 2.5kw.


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## KRE (Nov 29, 2011)

redcentinela said:


> Dont remember if I measure the two white cable or the two black cables for voltage. I measured one of those and had 0 voltage. I' ll check and let you know.


Based on your drawing, my guess is if you wire them in series you will damage the unit.
One thing to remember a gen set has two main (power) ratings, one is KW the other is Kva. You have to stay under the lesser rating our you will burn the unit up. The KW rating is the true power from the engine that does not change when you rewire a alternator, but the Kva rating changes greatly.
All single phase gen-sets are rated at a unity power factor( the voltage an current sine-waves are in step). 
Motor, transformers, F/lighting are lagging power factors, these loads always reduce the gen-sets Kva rating. They do not change the KW rating however.


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## gardner (Oct 21, 2014)

KRE said:


> On (US)240Vac only loads one does not need a neutral as the two 120Vac legs are 180* out of phase which is how you achieve 240Vac.


All equipment always needs a ground, and the neutral will be bonded somewhere to the ground and carry a potential close to ground. The key difference in north american setup vs, say, australian, is that in a NA 240 circuit both legs are hot -- at 120V to neutral.

Now an australian power drill or toaster or whatever is designed for one hot leg at 240V and a neutral leg. Feeding it from a NA circuit creates the chance that a chassis part DESIGNED to be neutral will instead be carrying 120V HOT. It is potentially dangerous.

A field changeover of the genset to 240V operation, if it works, is likely to yield an rest-of-world -- australian lets say -- configuration. This is where one leg is at neutral and bonded to ground and the other leg is at 220V.

Using this to power a NA appliance like a water pump or something could have a couple of issues. A NA appliance is generally insulated with the assumption that hot parts are at 120V to ground and we now have some parts at 240V to ground -- this is unlikely to cause serious danger, but would not be approved. The generator has one leg bonded to ground, and if the appliance is an inductive or capacitive load designed for two-hots, it could generate back-emf into the circuit -- into the neutral leg. Since the neutral is bonded this would cause the ground to carry a significant voltage -- particularly if it is not actually earthed. In any event, this arrangement would not be approved.


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## gardner (Oct 21, 2014)

aandpdan said:


> Wired in series you now only have half the output capacity. If it was 5kw before it is now 2.5kw.


120V x ~42A --> 5kW.
rewiring to 240V cuts the current in half but doubles the voltage, so
240V x ~21A --> still 5kW


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## KRE (Nov 29, 2011)

gardner said:


> All equipment always needs a ground, and the neutral will be bonded somewhere to the ground and carry a potential close to ground.


 The equipment could care less about a ground or neutral, the ground is there for safety only, and a neutral is just a return path to a ctr tap, be it a generator or transformer. If you take a transformer and apply 480Vac on the H side, the X side can be anything depending the turns ratio and there is no ground or neutral hooked up to power the X side device. Grounds are for safety only, nothing more.


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## redcentinela (Feb 26, 2015)

Gardener, in other forum somoene proposed the same wiring in order to have these inverters in series. 

The ground lug and inverter case are connected. Since it is a chinese inverter generator and cost me pretty cheap ( uncanny why 2 inverter units, each one supplying 120v at 60hz frecuency) I don't mind to give it a try to put it in series. 

Each inverter has one 20A CB for inverter 1 and one 30A for inverter 2. In order to provide some protection to the genie, I plan to install a double pole breaker but I am not sure about the amperage it should be. I was thinking about 15A or 20A.

I don't plan to use it with any 220v appliance. Just want both hot buses to be feeded by the genie. I have gas furnace, so the most powerfull appliances would be a medium fridge and a medium microwave and of course don't plan to use them both at the same time. And of course to light the fluorecent lights and a couple of fans.

Remember, it is for emergency back up to power the essentials. I live in the tropic and can live without water heater, have no well pump, no heater and all those things you have in the states.

Thanks for any comments.


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## gardner (Oct 21, 2014)

KRE said:


> The equipment could care less about a ground or neutral, the ground is there for safety only.


You say that like safety is a bad or unnecessary attribute. I don't want to come near any electrical installation put together with this mindset in play. It's how folks get electrocuted.


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## gardner (Oct 21, 2014)

redcentinela said:


> I don't plan to use it with any 220v appliance. Just want both hot buses to be feeded by the genie.


I *think* you could do this by feeding the same 120V hot to both busses. 240 volt loads will not get a potential difference between the two hots and will do nothing. Single pole loads will get a 120V hot.

There may be some safety issues with 240V appliances that can partially run -- eg: the stove doesn't heat, but the electronic display, oven light and convenience outlets work.


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## aandpdan (Oct 8, 2012)

gardner said:


> 120V x ~42A --> 5kW.
> rewiring to 240V cuts the current in half but doubles the voltage, so
> 240V x ~21A --> still 5kW


Right now he has two 2.5kw inverters, in PARALLEL, for a 5kw output.

Rewiring it, he'll have two 2.5kw inverters, in SERIES. That limits him to 2.5kw. 

I'm not using volts/amps. Stick with the wattage.


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## gardner (Oct 21, 2014)

aandpdan said:


> I'm not using volts/amps. Stick with the wattage


Wow. I would recommend looking up what "watts" means.


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## aandpdan (Oct 8, 2012)

gardner said:


> Wow. I would recommend looking up what "watts" means.


Thanks Gardner.

I've been looking at it as each inverter is rated at 2500 watts. That was what "stuck" in my head.

I do know P=IE, thank you very much for pointing my error out.

I'd still try the inverters in series. It should not be a problem.

You don't always need a ground though Gardner.


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## KRE (Nov 29, 2011)

gardner said:


> You say that like safety is a bad or unnecessary attribute. I don't want to come near any electrical installation put together with this mindset in play. It's how folks get electrocuted.


 Safety is never a bad thing, but the bottom line is the equipment will operate w/o a ground an many w/o a neutral. For any 120Vac load in the US you need the neutral with one hot leg to supply 120Vac RMS, but you can also power the same load with a transformer that is supplying 240, 277, or 480Vac on the H side and two 60 Vac legs on the X side. The key to any device is RMS potential voltage, it matters little if all the voltage is on one leg or 180* out of phase on two legs, the load will operate the same either way.


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## redcentinela (Feb 26, 2015)

Thanks for your response


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## redcentinela (Feb 26, 2015)

Here is a picture of the board side:


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## redcentinela (Feb 26, 2015)

Another one:


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## redcentinela (Feb 26, 2015)

*Re: China inverter generator 5500w


Don't know if a bad idea or not to try to set this genset in series, it did't work. No sparks or fireworks whatsoever. When in series it does not produce any voltages.

I tried swapping the black and white cables to set it in series with no luck as well.

Also tried to disconnect the black cable assy that connects both inverter modules, also with no voltages. With this cable assy disconnected only works the first inverter producing 120v. The second one does not.

This genset apparently only works with both inverter modules in parallel to produce the full 5000w.

Well at least I tried to make it work in series, but it didn't work.

No idea if the chinese produce this genset in single phase for 240v splitted like other gensets. Would be a hit but you can find only the 120v version in the USA. Honda and Yamsha have the monopoly by know, that is why those gensets are darn expensive but when the chinese come, prices will go down. 

What I will do is to put everything back to what it was, in parallel.


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## KRE (Nov 29, 2011)

If you can fine two 120 X 240 transformers that have the same impedance you can hook them together and get 5kw of 240Vac. HTH


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## redcentinela (Feb 26, 2015)

Thanks for the comment, but what about this:

redcentinelaThread StarterMember

All the neutrals and grounds in my house are shared to the neutral coming from the utility. I used a continuity meter to do it. 

In theory tell me if this may work:
I have a 120v, 30 A outlet in my genset, prepare a 10AGW, 4c cable ( remember I thought ithis inverter was going to work in 240v) to work for 120v. I wire and install the L14-30 male connector with only 120v in one leg. On the other tip of the cable I install a 10-40P male connector.*

Inside that 10-40P connector I make a jumper in order to have 120v backfeeding each leg in the 10-30R female outlet.*

Before doing all this, I turn the main breaker off an all 240v will remain off, except the drier' s which will remain on in order to let backfeeding.*

Also will turn off all the 120v breakers before hooking up the modified 10-30P connector to the drier's outlet.

I plug the modified extension to the driers outlet, turn on genset and then turn on one by one the 120v breakers.

As you can see, drier breaker is 240v, 30A. Genset is 30A at 120v.

Will I have some kind of problem with this set up?

Also for increasing security, I plan to install a main breaker inside the house ( main breaker is inside the utility counter box out of the home, it is a double pole 100A breaker.) of the same size 100A at the breaker box. There is a space provided for it.*

I don't know why many people say it is dangerous do this than running many extension cords dangling around ! How about tripping on one of them, how many extension cords are you going to use ?*

Remember, I will not use by any means to use any 220v because it is impossible with what I propose, just want to power both buses with a single phase 120v coming from the genset. Also plan to ground the genset to a close ground rod I installed recently. There is nothing connected to it actually. It is in the backyard close to where the generator is going to be, inside a garden storage shelter.

Any comments from anyone is welcome.


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## redcentinela (Feb 26, 2015)

Forgot pictures:


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## gardner (Oct 21, 2014)

redcentinela said:


> Any comments from anyone is welcome.


Please get a transfer switch.


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## KRE (Nov 29, 2011)

redcentinela said:


> Thanks for the comment, but what about this:
> 
> redcentinelaThread StarterMember
> 
> ...


 That will power everything in your home that is 120Vac, * BUT USE A TRANSFER SWITCH INSTEAD OF THE DRIER PLUG.* Back feeding power is a very dangerous way of saving money. No ones life is worth a light bulb being on, a microwave heating anything, or a TV/radio being powered that way. Instead just run ext cords out the window or door to the unit. remember what you can't see *Can Kill You.*


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## redcentinela (Feb 26, 2015)

How bad can it be to run it like that if I run only the essential equipment basically one at a time, electric power barely go down a few days in a year ? 

My house is made completedly of concrete and even an installation of a manual transfer switch is expensive since you have to break pure concrete to install tubing, cables, and all the hardware required for this operation. It is not like the USA that almost all home are made of wood and wiring is easy. 

I don't even plan to reach 3kw. I have a small house, gas stove, all lights are fluorescent and a couple LEDs. The biggest appliances are the fridge and the microwave and in case of emergency I don't plan to run both at the same time. Drier outlet is about 20 feet away from breaker box. 

I a not justifying, Just asking the possibility to run the essentials in an emergency. I know that the safest way is installling a transfer switch. 

Eitherway, you already answered my doubts. 

Thanks all of you who dared to answer questions that apparently are taboo.


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## aandpdan (Oct 8, 2012)

I'll add my voice, put in the transfer switch.

During an "emergency" you might be rushing around a bit and forget to turn off the main breaker. That's all it takes. You could kill a lineman working to fix the problem. 

Besides, when the power comes back on it can fry your generator.

Never mind the "suicide" cord you need to make this work. Exposed live connections during an "emergency?" You're asking for trouble.

Do it right or don't do it at all. Just using extension cords is a lot safer than backfeeding. 

Another thing, if you have kids and they've seen "daddy do it" they may try and forget something - and get killed.

Please use a transfer switch and the appropriate cord set.

FYI, Not all homes in the USA are made of wood. There are many made of brick/concrete as well. Many section require all wiring to be in conduit too.


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## redcentinela (Feb 26, 2015)

Ok, what is the difference between switching a manual transfer switch and switching off the main breaker ? 

Ok, I can substitute a the drier outlet for a power intlet box and forget about the so called suicide cable.

Still can't do it?


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## aandpdan (Oct 8, 2012)

A transfer switch only allows the power from either the utility OR your generator. It "locks out" the other selection - pretty much making it foolproof. Just switching the main does not prevent you from accidentally connecting both together.

Check out an interlock. Most panel manufacturers make them and they are fairly inexpensive - much less than a transfer switch or panel.


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## redcentinela (Feb 26, 2015)

I'll check the interlock. By the way, this info regarding this type of generator has been very clarifying for me. Now I know what the ground termina is used for: to attach a cable in a motorhome or truck's frame. If used as a home's backup, this type of gensets have no problem using house wiring grounding system.*

Here is the info between " " :

"*You cannot bond the neutral to ground on a Honda and similar generators because there is no neutral. You have hot L1, hot L2, and ground. L1 and L2 are about 62 volts to ground and about 124 volts across the two. (Cross hot 62 volts to ground and you'll either pop the overcurrent protection or smoke the very expensive electronics.)"


In understand here that my genset has an unfloating neutral and by no way I shoud bound the neutral to ground.


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## redcentinela (Feb 26, 2015)

I will buy an interlock kit, the K-5110 . As someone else mentioned, I should install a full 240v generator connection system, but change the connection cord so there is a jumper across the legs to feed both busses when you use the 120v generator. With this kit apparently I can use both systems, 120v if I make a jumper in the cord and 240v without the cord modified. 

Good thing for those who have small inverter generators like me who wans to save $$$$ in gasosline since smaller inverte gensets consume less gasoline, even more with Eco Throttle On.


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## KRE (Nov 29, 2011)

redcentinela said:


> Good thing for those who have small inverter generators like me who wans to save $$$$ in gasosline since smaller inverte gensets consume less gasoline, even more with Eco Throttle On.


That is not the case, all resip engines are heat engines. Many have a very good heat rate (KW/E vs btu input) but to say inverter gen sets are the best in incorrect to say the least. Resip heat engine run between 13,500 btu input to 1 KW/E output, to the very best which are in the 4800btu input to KW/E output. When you look at the BTU content in a gallon of gasoline, propane, diesel fuel, bunker C, or therm of N/G (let alone LNG), engine design, operation all play into the btu vs kw/e numbers. This does not even take into account the combined cycle units that are around.


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## redcentinela (Feb 26, 2015)

I boughy an interlock kit made by the same manufacturer of my breaker box. Interesting that this type of devise can be use in backfeeding ( a bad word for many people here or almost all the electricians I've read. )

It includes intallation instructions, drills, corresponding nuts and screws for proper installation, etc.*

Why then as soon as somoene say it is a bad thing to say " backfeeding" . ?

Also instruccions say that backfeed breaker must match the one with the genset, in my case woulb be a 30A.

This kit is to be to used with main breaker deom 70A to 125A.
For bigger gensets also come a kit slightly different with another part number.

I think every company which manufacture breaker boxes, manufcture their corresponding interlock kit.


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## redcentinela (Feb 26, 2015)

Here is a picture of the kit:


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