Any Honda Inverter generator experts out there? - Page 1
Forum section: electronics / projects

author: Jester
author_rank: Frequent Contributor
timestamp: April 06, 2023, 11:45:22 pm
content: We just got through an ice storm, no utility power for 24 hours. Fortunately about a year ago a neighbor rolled a 10HP generator to the street on garbage day with a note "wont start" it looked like it was basically unused. I wheeled it home took off the carb and cleaned the gum out and it works like new. This is a 120V/240V unit so I made an umbilical cord that mates the generator to a receptacle I located on the outside of the house that is in parallel with my welding circuit. I just open the main cutoff from the utility, plug in the umbilical cord start the generator and enjoy. Works like a charm, and both phases of the breaker box are powered.Except it's really noisy. I'm considering getting two of the small (and quite) Honda inverter generators EU2200i.The problem I anticipate is that although these can be paralleled, it would be much better if I could connect these one per phase for a couple of reasons:1) The various loads that I really need during an outage are evenly distributed on the two phases2) so I have 240V when needed, for example for the hot water heater.It seems likely that if I connect them one to each phase they either won't be in sync so 240V will constantly vary between 0-240V, or if they are in sync than across the two phases I will have 0V, unless there is a way to get them to be 180 degrees with respect to each other.Anyone have any ideas or insight?

author: james_s
author_rank: Super Contributor
timestamp: April 07, 2023, 12:42:05 am
content: I have the older EU2000i and it has been fantastic, I love it. It's so quiet I can leave it running all night and it's very fuel efficient.You cannot get 240V out of it though, the parallel kit that allows you to run a pair of them is just that, parallel, it's still 120V. What I do is use a cable that has both phases wired together where it plugs into the generator inlet on my house. This works just fine, the generator is too small to run any of my 240V loads anyway so I just shut those circuits off. Even that isn't really necessary though, it won't hurt anything to have both hots floating at 120V on a 240V appliance, the voltage across any of the loads will be 0V.If you *really* want 240V you could use a center tapped step up transformer but with such a small generator I don't think it will be very useful.

author: jonpaul
author_rank: Super Contributor
timestamp: April 07, 2023, 10:25:37 am
content: impossible to synchronis the two independent generators.Risk to the inverters and to any loads.sell them, get a new 240V rated generatorjon

author: Jester
author_rank: Frequent Contributor
timestamp: April 07, 2023, 11:26:59 am
content: Quote from: jonpaul on April 07, 2023, 10:25:37 amImpossible is a pretty strong statement.1)The Honda generator referenced already comes equipped with a synchronize feature to allow multiple generators to be be paralleled.2)Obviously power utilities synchronize generators before connecting them to the grid all the time.So definitely not impossible.

author: Gyro
author_rank: Super Contributor
timestamp: April 07, 2023, 11:27:53 am
content: QuoteHe hasn't bought them.

author: Jester
author_rank: Frequent Contributor
timestamp: April 07, 2023, 12:18:49 pm
content: This might be pretty simple now that I think about it.The generator described already has a synchronization feature, from what I have read you connect two shrouded banana jack leads between the two generators then start one, and when you start the second it will synchronize to the running unit. I also read (needs to be verified) that the banana jacks simply connect to the Mains receptacle implying that the inverter output can tolerate a 120V source at its output. So simplest case just reverse the polarity of the banana jack leads and the the second generator will run 180 degrees out of phase with the first generator. To be on the safe side it might be a good idea to use a small isolation transformer for the synchronization signal.Since the neutral of these generators is floating, I don't see why this would not work.

author: MarkL
author_rank: Unknown
timestamp: April 07, 2023, 03:17:37 pm
content: Quote from: Jester on April 07, 2023, 12:18:49 pmThis will probably get the generators running 180deg out of phase with respect to the neurtal and hot, but as you also point out the banana jacks are directly connected to the outlets.You can't then connect the outlets to get 240V. It will be a short. Draw it out.One solution is to feed an appropriate sized 120V step-up transformer to handle your 240V loads.But if you're really aiming to run a hot water heater mentioned in your first post, you're going to need a lot of power. A typical home hot water heater is around 5kW at 240V, and that could run for 30 minutes or more. If you want to stick with Honda, you're looking at their largest EU7000 series, or a pair of their smaller ones that could be paralleled for 5kW continuous at 240V.You could also just give up on the 240V requirement. A 240V hot water heater could also be run on 120V with some modification, but it would heat a lot slower. Maybe not a problem in an emergency.

author: Jester
author_rank: Frequent Contributor
timestamp: April 07, 2023, 04:22:55 pm
content: This is what I was thinking, good point about the diagram.