Are you sure upgrading to 3 is even an option? If you're using split phase, then you'll need multiples of 2 of the 6500EX inverters....so setup as 2, 4 or 6. If you have them configured as only outputting 120 volts, then you can use 3 or if you're configuring in 3 phase power, then 3 inverters can be used. But I'm pretty sure if it's split phase power, you'll need multiples of 2.
EG4 new AIO rated 12K output and 18kPV aka "EG4-18Kpv-12LV"
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Gavin Stone
Solar Addict
That is correct. You’d need 2-4-6 of the 6500’s for split phase.
You are correct, I hadn't realized this point. Thx
Zwy
Emperor Of Solar
The EG4 6500EX is a good unit really. It would depend on when you purchased as to whether you might see problems. The units built until a this past winter may have problems, not all do. Gavin has a video where he removed the LV6548's again and installed the latest EG4 6500EX and reported no problems.
I threw everything at the 6500EX's when I had them installed and it did perform to expectations. No issues there. It is the flickering light/voltage regulation problem and dirty sine that was a problem. SS has those 2 inverters now, I will update when I get replacements installed. For now I'm running 2 MPP LV6548's and have scoped these and they are clean power. No flickering lights and output voltage has been rock steady. My array was setup for 400VOC due to the distance from array to inverters so I'd have to run more wire if I went totally LV6548.
I would not get in any hurry to dismiss the 6500EX. As you already have these in hand, I'd get my array setup, work on the batteries and then decide if you want to test the 6500EX's or switch to a new unproven AIO inverter. By new and unproven, just like the 6500EX compared to the LV6548, the 18K PV unit may have changes compared to the Luxpower version that can create problems.
Gavin Stone
Solar Addict
Those first ones were a bit more of a pain to install because of the smaller AC terminals. But overall great units.
Actually opened one up to see if the wire would fit and it was a bit tough to get it in there.
Zwy
Emperor Of Solar
Mine were from the same time frame. But I have the larger terminals, I see you have the smaller terminals. https://diysolarforum.com/threads/eg4-6500ex-ac-wiring-size.55234/post-708417
If you can't get 4AWG to slide in easy, then it is the earlier version.
Gavin Stone
Solar Addict
The hardware problems occurred somewhere around November of last year I believe from what James has said. Those earlier versions didn’t have any common problems that I know of other then the fault 61 issue. And that was resolved with firmware.
Ok, thks.
Zwy
Emperor Of Solar
From my experience with the inverters I received that were manufactured mid 2022 with the larger gray terminals, the hardware problem started around then.
I've been doing quite a bit of reading on the Lux and Fortress which are quite similar to the EG4 18K PV. Assuming there's no fundamental change in how EG4 is handling this. the first inverter will do 200A and each subsequent inverter will do 100A pass through. So if you're looking to do 400A pass through, you'll need 3 of the inverters in parallel (200A for inverter 1, and 100A each for inverters 2 and 3). Again...this is assuming the EG4 version is hasn't changed in this regard.
SignatureSolarJames
Try Solar, the Grid will always take you back
We can review this, but I believe thaat 400A is possible with 2 units
Quattrohead
Solar Wizard
I think you can have different numbers of unit's on each phase, like 1/2/3 or 1/1/2 etc.
Eddie_LuxPowerTek
Solar Enthusiast
that's wrong info I believe. As long as your main panel can handle a sufficiently high current, technically, paralleling two inverters to the grid is like having two bypass switches that can support a current of 400A. The maths behind why three units are required to support 400A is difficult to understand.
PS: Due to impedance differences in the circuit, there may be a slight loss of equal current distribution.
fromport
Solar Addict
That is exactly the case. the wires connecting everything together might be off with different length/impedance .
If 400 amps pass through would be flowing with 2 inverters in parallel, one inverter might carry 220 and the other 180 amps.
I think it is, in general, not a bad idea to degrade the pass through current per inverter with multiple units in parallel.
eg:
2 units: 380 amps (20% derated)
3 units: 450 amps (another 20% derated per inverter)
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that's what the technical video from fortress said. and i agree, if 1 inverter can do 200A, then 2 in parallel should be able to do 400A. What the guy in the video was explaining was that there was some type of intentional derating for the subsequent inverters in parallel. keep in mind of course that the eg4 18k pv may do things differently.
Eddie_LuxPowerTek
Solar Enthusiast
where's that video? can you pls provide a link
FilterGuy
Solar Engineering Consultant - EG4 and Consumers
Maybe I am just slow, but the response confuses me. It starts by saying "That's wrong info I believe" but then seems to support the idea that 3 inverters are needed. Can 400A be safely supported with 2 inverters, or is there some de-rating that should be done?
Eddie_LuxPowerTek
Solar Enthusiast
lol. really? excuse my English expression then. I was saying "believe" meant it may have other reasons making Fortress people say so. but trying to clearly state that 2 in parallel is just 2 switches in parallel, technically they together can support max. 400A bypass current. and after that, I said, it's hard to understand why it requires 3 pcs in parallel to support 300A. I wasn't 100% sure if any conditions missing behind this saying.
timselectric
If I can do it, you can do it.
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Can two units support 400a, yes.
Will a full 400a split equally between the two, likely not.
If you don't de-rate them, you will probably have nuisance tripping of one or the other.
(If you actually have a 400a load)
Will a full 400a split equally between the two, likely not.
If you don't de-rate them, you will probably have nuisance tripping of one or the other.
(If you actually have a 400a load)
FilterGuy
Solar Engineering Consultant - EG4 and Consumers
Thanks!!
FilterGuy
Solar Engineering Consultant - EG4 and Consumers
True that. I can believe EV chargers will increase the loads at a lot of residences, but even with EV chargers, a full 400A load is well beyond what most residences will ever experience.
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