# Has anyone tried to parallel a Honda EU7000 and a Champion 8750w inverter?



## jeb (Feb 16, 2021)

Just curious if anyone has done this successfully. Of course the 8750 does not natively support a parallel setup...but with a little cheater cord...
Start the Champion first...
Then let start the Honda so it can sync to the Champion.

Basically this is the deal; I want to run the house on the EU7000, but when its hot weather, I would like to be able to have AC.
The AC unit is a Goodman CLJ42-1A and when I use a test probe on the L1/L2 side I'm seeing around 12Amps per leg. On startup I'm seeing 30amps per leg (I have a hard start cap added on this). My meter does not store the max current draw..so this is just me looking at it and hoping I have the correct peak value as it comes up (assuming this meter is even fast enough to measure this in rush current).
Compressor is rated at 16.6 RLA and 86 LRA.

Furnace/blower is 17Amps @ start and 7amps continuous on L2.

Without the AC on and being careful with power usage, I'm at around 13amps per phase - I have a couple of freezers that will bump me up another 2 amps or so per phase when they are running...but of course those are intermittently running.

The deal is...the single EU7000 is not enough to run this and anything else with such a high current load on startup. So was hoping that adding the Champion will give me even more than a 2nd EU7000 since it has a higher running and peak wattage. If its not hot out...I can get by with the single EU7000.

I have a Generac 15KW/22KW peak which is now getting to be near 15years old and I'm migrating that to the backup status in the shed. Plus the THD is horrific on that genset and it sucks fuel/natural gas like its free  and its louder than a rock concert.

Thoughts?

Thanks,

-J


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## jeb (Feb 16, 2021)

I should add, my existing setup that I've had for 15years is a 50amp gen feed with an interlock into a GE panel. So its a whole house setup. The old Generac seems to handle it...but its at the point I'm ready to retire it because of noise, fuel consumption and dirty power.


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## Browse Deweb (Jan 16, 2021)

That 3.5 ton AC unit draws 86 amps on startup, so you will probably need a soft start kit for it. Something like the Micro-Air EasyStart 368. There are videos on Youtube showing successful parallel operation between Honda and Champion inverters. If I were to run a setup like that, I'd probably want to have a 50A cord, outlet and breaker feeding the house panel. Most inverter generators in the 7-8kw range only have the 30A outlet. I know that the Honda EU7000is parallel kit has the 50A connection.


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## jeb (Feb 16, 2021)

Ya, my existing setup is a 50A plug in a NMEA outdoor enclosure that feeds a two pole breaker with the interlock off the main.

Regarding the Micro-Air EasyStart...what current draw will this drop be down to? It says on the link "up to 75% reduction"...but I don't think I want to go with the 'best case' scenerio for my calculations. What is the 'typical' power draw drop using these?

With a 75% drop..that would take be down to 21.5amps peak current which would be great...but not sure if that is a real world number or not.

Thanks,

-J


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## LaSwamp (Mar 16, 2021)

In my experience, trying to run a whole-house a/c unit during an outage is best done with a whole house generator. If you're using portable generators, it's far easier to pick up a couple of window units and use them to keep portions of your home cool. If you lose power often enough that it's a pain to use window units like that, then you'd be a lot happier, again, with a whole house Kohler. During an outage, you're just trying to stay comfortable until crews can get the lights back on again. You can try to hot wire two inverters together, but I don't know how well that would work. Most of the parallel kits max out at 6k watts and 50 amps, although I guess you could home brew something that would provide more juice. If you _really_ need to power your entire home during an outage, your best option is to get something that will do it natively.


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## Browse Deweb (Jan 16, 2021)

jeb said:


> Ya, my existing setup is a 50A plug in a NMEA outdoor enclosure that feeds a two pole breaker with the interlock off the main.
> 
> Regarding the Micro-Air EasyStart...what current draw will this drop be down to? It says on the link "up to 75% reduction"...but I don't think I want to go with the 'best case' scenerio for my calculations. What is the 'typical' power draw drop using these?
> 
> ...


There are a bunch of Youtube videos with people showing real world results of the soft start kits. I think most of them are at least a 65-70% reduction in inrush current.


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## Ground Fault (Jun 9, 2020)

Jeb thanks for posing this question. I too would like to parallel two dissimilar wattage generators, my EU7000 with a Generac XP8000E, IF it can be done SAFELY, meaning safe for me AND safe for the equipment. I would also like to parallel a EU2200 with an EU2000. I have been previously warned off doing either: I posed that paralleling question in another thread and was immediately told that paralleling two generators of different wattages was a risky proposition in that the equipment would suffer. I took that at face value and abandoned all hope of doing so.


With you thread containing no such cautionary warnings _to this point_ I am again on the front burner about doing this, IF...IF IF IF it can be done successfully and without risk to life and limb, and of even greater importance, to the equipment. So, what say ye, Masters of the generator universe?

And Jeb, for what it is worth, and I know you know this...YouTube is no NFPA. I know I am preaching to the choir here when I post, just because Little Johnny posted his generator vid on YouTube doing it does not make it an industry norm. Just because they have people on there shooting 10-gauges off their crotch don't mean that I'm gonna' try it...again. Let's see what the gurus say.


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## LaSwamp (Mar 16, 2021)

Ground Fault said:


> Jeb thanks for posing this question. I too would like to parallel two dissimilar wattage generators, my EU7000 with a Generac XP8000E, IF it can be done SAFELY, meaning safe for me AND safe for the equipment. I would also like to parallel a EU2200 with an EU2000. I have been warned off doing too: I posed that paralleling question in another thread and was immediately told that paralleling two generators of different wattages was a risky proposition in that the equipment would suffer. I took that at face value and abandoned all hope of doing so.
> 
> 
> With you thread containing no such cautionary warnings _to this point_ I am again on the front burner about doing this, IF...IF IF IF it can be done successfully and without risk to life and limb, and of even greater importance, to the equipment. So, what say ye, Masters of the generator universe?
> ...


Of concern is that the Champion doesn't have parallel ports, so it doesn't support that operation natively. Seems odd that Champion would do that given their smaller inverters have that function. Perhaps Champion feels like the big inverter already makes enough power and doesn't need to parallel with another inverter. I have a brother in law who now has a whole house Generac, but before that, he had two portables that he connected to his meter. He and my sister lost power for about a week after Hurricane Gustav in 2008. I don't know how he had it wired, but the two generators (non-inverters) ran together and provided power to the home. They couldn't power anything big like the central a/c, but they were able to power the fridges, ceiling fans, and TVs. Interestingly enough, once he got his Generac, he has not had a significant power outage since. But each storm season brings promise that he will get to use that whole house unit. I haven't had a significant outage since the 2016 flood, before I got my first generator. The trick to never having another power outage is to be prepared for one, it would seem.


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## iowagold (Jan 22, 2020)

jeb said:


> Just curious if anyone has done this successfully. Of course the 8750 does not natively support a parallel setup...but with a little cheater cord...
> Start the Champion first...
> Then let start the Honda so it can sync to the Champion.
> 
> ...


bad idea!
stick with honda with honda only
and same models as well


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## drmerdp (Apr 10, 2018)

I’m tempted to pick up a predator 9500 inverter gen to pair with my EU7000. I haven’t decided yet.


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## jeb (Feb 16, 2021)

iowagold said:


> bad idea!
> stick with honda with honda only
> and same models as well


Why Paul?


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## vila251 (Jun 14, 2021)

drmerdp said:


> I’m tempted to pick up a predator 9500 inverter gen to pair with my EU7000. I haven’t decided yet.


how would you parallel them together? I just picked up a EU7000 and waiting for delivery


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## Browse Deweb (Jan 16, 2021)

vila251 said:


> how would you parallel them together? I just picked up a EU7000 and waiting for delivery


Probably a suicide cord.


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## iowagold (Jan 22, 2020)

bad idea!


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## Browse Deweb (Jan 16, 2021)

iowagold said:


> bad idea!


Yep. Inherent in the name.


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## Ground Fault (Jun 9, 2020)

Yes, but what is the science behind it being a bad idea? Why?


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## Browse Deweb (Jan 16, 2021)

Ground Fault said:


> Yes, but what is the science behind it being a bad idea? Why?


The only thing I can think of other than the shock risk if using a double ended male cord to join two generators is that the internal circuitry of the generator feeding the house isn't designed to handle the excess current being provided by the two generators.


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## drmerdp (Apr 10, 2018)

I made my own cord with insulated banana plugs. Same thing that the manufactures have on their parallel kits. 12ga wire protective sheathing, Shri k tube ends. But this was for paralleling smaller EU Honda’s.

If I were to parallel 2 eu7000s or a combination of large inverters gens it’d need to be 10ga minimum and I think I’d likely buy the Honda parallel kit.

It’s a bit pricy but it’s a decent value


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## Ground Fault (Jun 9, 2020)

Okay, in the absence of a clear answer to the question, and in an effort to move this effort forward let's break it down and unpack the moving parts:

Browse, I understand and accept the risk of using double ended male electrical connectors, but that is not what warns off the use of dissimilar wattage generators in parallel. As for the internal circuitry not being able to handle EXCESS wattage: Double-ended male paralleling plugs aside, engineers always include a margin of safety when designing anything. It is called service factoring, and although I haven't gone down the rabbit hole researching the NFPA regs on generators I am pretty sure that they have been written using NFPA service factoring. That's how you make things safe. Depending on the severity of the intended working environment a service factor can range from 2.0 to upwards of 4.0 (think rock crushers or an elevator, or for our purposes, and electrical grid). I seriously doubt that the designers of parallel-capable generators ever go lower than a 2.0 SF. I received a ton of power transmission product training after college, and although it was long ago I do not remember any manufacturer recommendations to apply a service factor of less than 2.0 to those prime mover mathematical formulas. If generator design basics are commensurate with the hydraulic and pneumatic design basics I studied I am pretty sure that mild wattage difference is not the reason we shouldn't parallel two dissimilar generators. VERY EXCESS wattage differences yes, but somewhat similar wattage, no. I can see the danger in paralleling a EU7000 INTO a EU2200 COMPANION, but what about feeding an EU2200 into an EU3000, or even a EU7000? All I want to do is parallel a EU2000 with a EU2200. Not that dissimilar. If there is circuitry inside that is DESIGNED to accept paralleling two generators, I CONTEND that internal circuitry is probably service factored at least 2.0 and can handle +/- 2x wattage differences. So setting wattage disparities of less than 2.0 aside, is the problem a CONTROL OR PROGRAMMING issue rather than a capacity issue? What's at play here?

Consider, the EU2000 has a running wattage of 1600 watts, 2000 surge. That means the internal circuitry is SERVICE FACTORED for AT LEAST 1.25, a 25% HIGHER/lower wattage variance. All day long. Did the engineers design it such that it would blow up if it surged to 2001 watts? No. My EU2200 has only 1800 running watts/2200 surge, only 200 watts higher than the EU2000. Shouldn't the paralleling circuitry of both be able to safely deal with their 200 watt variance, or stated differently, a 1.1 service factor? What engineer would design anything with only a 1.1 service factor? NONE of them! So isn't the EU2000 and the EU2200 safely inside each other's paralleling margin of error? They total together 800 watts of surge capacity. Wouldn't prudent design make sure that EITHER unit could safely endure ALL 800 watts of in-rush surge BY ITSELF? It would seem so to me. There seems to me to be enough surge capacity there to safely do it, but I may be wrong. I usually am, but tell me why I am.

Is the paralleling problem then a _time-factor_ thing rather than a wattage thing? HOW LONG it can do it safely rather than how much wattage safely. Get the engineers down here. I am calling a meeting...

*So, back to the original question: WHY?* I'm not sure I will ever parallel anything, but I want that option open to me, IF it can be done safely. If not, _I want to know the science of why I can't._ I do not want to smoke my generators.

As a reminder, Honda didn't design their generators to run on propane or NG either, but we do it anyway. Safely.


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## Browse Deweb (Jan 16, 2021)

Yep, it clearly works based on the example videos available. Other than seeing two EU7000is connected using their parallel kit, I haven't seen two of the larger 240V generators working together without an appropriate parallel kit. If you wanted to parallel two large units to feed a house with a 50A cord, you either need a generator with that output style, or you need a parallel kit with that output available. Would be interesting to see a working example.


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## drmerdp (Apr 10, 2018)

Ground Fault said:


> Okay, in the absence of a clear answer to the question, and in an effort to move this effort forward let's break it down and unpack the moving parts:
> 
> Browse, I understand and accept the risk of using double ended male electrical connectors, but that is not what warns off the use of dissimilar wattage generators in parallel. As for the internal circuitry not being able to handle EXCESS wattage: Double-ended male paralleling plugs aside, engineers always include a margin of safety when designing anything. It is called service factoring, and although I haven't gone down the rabbit hole researching the NFPA regs on generators I am pretty sure that they have been written using NFPA service factoring. That's how you make things safe. Depending on the severity of the intended working environment a service factor can range from 2.0 to upwards of 4.0 (think rock crushers or an elevator, or for our purposes, and electrical grid). I seriously doubt that the designers of parallel-capable generators ever go lower than a 2.0 SF. I received a ton of power transmission product training after college, and although it was long ago I do not remember any manufacturer recommendations to apply a service factor of less than 2.0 to those prime mover mathematical formulas. If generator design basics are commensurate with the hydraulic and pneumatic design basics I studied I am pretty sure that mild wattage difference is not the reason we shouldn't parallel two dissimilar generators. VERY EXCESS wattage differences yes, but somewhat similar wattage, no. I can see the danger in paralleling a EU7000 INTO a EU2200 COMPANION, but what about feeding an EU2200 into an EU3000, or even a EU7000? All I want to do is parallel a EU2000 with a EU2200. Not that dissimilar. If there is circuitry inside that is DESIGNED to accept paralleling two generators, I CONTEND that internal circuitry is probably service factored at least 2.0 and can handle +/- 2x wattage differences. So setting wattage disparities of less than 2.0 aside, is the problem a CONTROL OR PROGRAMMING issue rather than a capacity issue? What's at play here?
> 
> ...


Here’s a good bit of reading for you. The underlying issue with paralleled operation of 2 inverter generators with 120/240v output appears to be “neutral cross currents”. Honda’s eu6500s we’re not parallelable, but the eu7000s are. From what I’ve read back in the day, changes to the inverter and the addition of a couple simple noise filters are the two main changes that allowed for safe parallel operation.








Paralleling Honda EU6500s for 100A Output


I have developed a new HD Plug-n-Play Pkg. that enables the paralleling of two Honda EU6500 inverter generators to generate 100 Amps of power. A complete system consists of two modified Honda EU6500s, a Paralleling Control Box, and one of our Transformer/Distros (either 60- or 84- Amp.) Parallel ...




cinematography.com


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## Ground Fault (Jun 9, 2020)

Thanks Dr! That's the science behind the question. That answers why not to do it. I don't understand most of it, except the word dangerous from a guy who knows way more than I do. I will take his word for it. Good enough for the girls I go with. I believe our work here is done. Next project...

Onward, through the fog...


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