Inverter brands

booboo120
booboo120 Registered Users Posts: 12
I am somewhat at a quandary, I have been living off grid for 10 years now and am putting up a Bergy windmill to supplement my winter power needs. The windmill should also supply enough additional power that I can operate my well pump off the battery bank in lieu of running the generator to fill the water storage. The issue lies in the fact that I have a Trace SW4024 inverter that is 120-volt output, my original intent was to add an additional SW4024 inverter to get the 220 V that is required for my well but this inverter is no longer available. So I have been looking at the Outbacks. It appears that I would be better off finding a used SW4024 and the link cable then upgrading to the outback FX series. I would like any opinions regarding life/reliability/performance of the Outback brand versus the Trace. The SW4024 that I have has only had one minor problem in 10 years and that was the loss of a cooling fan bearing, no bid deal to replace
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Comments

  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Inverter brands

    Outback does have a good reputation...

    The neatest solution at the moment for 120/240 VAC split phase do everything inverter (AC input charger, opt. generator control, grid tied, off grid, hybrid with internal transfer switch, both AC1 line and AC2 gen input, one unit that does 120/240 VAC 60 Hz support native support, high efficiency)--the Xantrex XW 6048 (6kW, 48 volt) is a hard unit to beat:

    Xantrex XW website
    Xantrex XW pricing from our host NAWS

    They also have a 4kW / 24 VDC input inverter too... But, if you can swing the 48 volt bank (400 AH minimum battery bank for 6kW output)--it is only $400 more for twice the energy output (basically, much of the circuitry is designed based on maximum current flow--doubling the input voltage allows doubling the output rating with few internal changes.

    NAWS also sells other brands (including Outback), plus a couple nice inverter FAQ's you can review.

    There is the option (if $$$ is a concern) where you can get a simple Modified Square/Sine Wave inverter and run a water pump with the cheaper MSW inverter. (see water pumping faq in the "other brands" link for details)

    However, "we" always recommend that you go with a good quality TSW (true sine wave) inverter if you can justify the costs.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Inverter brands

    I'd second the Xantrex for a 240 V application. Even though I have Outback, they're a bit tricky for 240: you have to 'stack' two. The Xantrex is 240 in one unit, easier to setup.

    That said, how big is the water pump? If it requires 240 it's probably 1/2 HP or larger, right? Sometimes you can run one off a step-up transformer. And whereas you can run a big motor off 120, the current draw can be impractically high. Also, in combination with your other loads it may overwhelm your present inverter.

    As for MSW inverters ... Speaking as someone who used to work for a company that builds many, many motors of this type I do not recommend it at all. Sorry to contradict you, Bill; it just isn't a good idea.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Inverter brands

    Marc,

    I agree with you that MSW's are not a good idea -- but I cannot argue that there are folks that run them very happily in the right application.

    Over-sized motor loafing along for the pumping application can work...

    Motor running just a the edge of its maximum performance can overheat/early life failure when put on a MSW.

    If there are controller electronics involved--the "square edges" of the MSW inverter can confuse them/overheat them too...

    In general, if the application can suffer failures (cheap to repair or replace, OK if there are "issues")--then cheap MSW's can work.

    If a person is off grid, using expensive equipment, and cannot tolerate failures (out in the middle of nowhere)--then TSW (with backups parts/components for critical applications) is the best way to go--even when significant co$t$ are involved with the TSW inverter.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • booboo120
    booboo120 Registered Users Posts: 12
    Re: Inverter brands

    I live in the mountains and live on the off/no grid solar system. I had been operating a 13kw propane generator for the well and batteries charging during the winter months until I could get the windmill for fill in on stormy days. This was the intent from day one 10+ years ago “then Trace screwed me up”. The well pump is 2&1/2 hp 265' set depth plus 152' too the water tank at the top of the hill plus 8' of tank makes the total lift 425', so a step-up transformer is a no-go for a long-term quality system. I have considered the idea of a XW4024 but it appears that I would also need the generator control option and the system control to have the same features that the SW4024 has, which places the XW at pretty pricey. Reconfiguring batteries, charge controller, Bogart meter etc.. for 48 VDC would be very time consuming. The other thing that concerns me, is that it also appears that the XW is not as robust as the SW (weight is less features are less etc...) all of which brings me back to the same quandary. If I am forced to upgrade how do we feel about the Xantrex vs. the outback. I have seen some sw4024’s on the internet but most every time I contact owners about them they have no concept of what software version their inverter has/had which is important if I am going to stack them, it makes me nervous buying things when the owner knows not what he ownes.

    Garth
  • jeffkruse
    jeffkruse Solar Expert Posts: 205 ✭✭✭
    Re: Inverter brands

    I thought I read in the Xantrex documentation that they dont recomend running a motor over 1 HP with their inverters.

    I have the Xantrex 4845 inverter. It's only been in service for a little over a month now but it works great. I think I paid $2700 for it.
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Inverter brands

    You are right that you can't possibly run that pump from 120. But you have another problem; it is my opinion that a 4 kW inverter isn't going to handle a 2 1/2 HP pump lifting water all that way. The start-up current would be enormous. Difficult to accurately determine too, as the Kill-A-Watt meter doesn't handle 240.

    Bill: would it work to put K-A-W on one leg and double it, or will the neutral reference go crazy? Probably can't "pair up" a couple either, eh? I've no idea how they're wired up inside so I don't know.


    So the start-up current could be 30 Amps or even more and the running current could be 20 Amps. It is difficult to say from just the HP rating as there are other factors that very the actual power draw.

    I think you need to get a firm handle on the pump's actual power usage in Amps or Watts before you can decide what inverter to go for. It may be time for the 'great upheaval' you've been trying to avoid. Nasty, but it can be done.
  • Solar Guppy
    Solar Guppy Solar Expert Posts: 1,989 ✭✭✭
    Re: Inverter brands

    The XW has all the features the SW had plus more. Its true sinewave, doesn't lose setting, more efficient and is True split-phase.

    I'm curious to where you got your information the SW had more features or better performance?

    The Outback FX inverters are fine for smaller systems, but don't match the features ( like generator support ) or efficiency the XW line has.
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Inverter brands
    The Outback FX inverters are fine for smaller systems, but don't match the features ( like generator support ) or efficiency the XW line has.

    Solar Guppy: What do you mean by 'generator support' ?

    I'd say the difference is the Outback is more difficult to set up and costs more for the same amount of output. I still like mine, though; it's a 'tank'! :D

    The Xantrex is still the better choice for this application.
  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    Re: Inverter brands

    Looks like 2 choices,

    continue running the pump off the genset (Have you ever watched the throttle action when the pump starts up, does the genset notice it, or
    does it lug down for a couple seconds)

    get the big 6048 inverter, and hope it can start the motor. (it's supposed to have a pretty good overload rating)
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • booboo120
    booboo120 Registered Users Posts: 12
    Re: Inverter brands

    Pump motor is a capacitor start; full load amp draw “measured” when the tank is full and the water table is at it’s lowest point, is 9.83, Amps, start-up inrush lasts .00256 seconds and is 28.62 amps. The generator notices the start-up but no up-throttling just a minor notice of sound change, the only thing that the generator sees as a 220VAC load is the water pump. I set the system up in the beginning with a slightly up-sized pump to minimize full load amps and inrush knowing the intent of the future. At the TDH “total dynamic head” of my system, I am more then adequate in operational sizing. It cost more up-front partially because it has 8 more stages then required, but is worked far less then the 1& ¼ Hp required to meet the TDH and it fills at 10GPM with no hassle. I have over the years run air compressors 3HP, at 110 VAC, table saws, radial arm saw, jointer, planer, band saw etc while building the actual house and living in a large camper while the wife was watching TV or whatever. The SW is a fine piece of equipment as far as I have seen. The information regarding the apparent differences between SW’s & XW’s was garnered from downloading the O & M’s from Xantrex and my original manual. I can clearly see a major weight difference and many adjustments are “or at least appear to be” no longer available.
  • jeffkruse
    jeffkruse Solar Expert Posts: 205 ✭✭✭
    Re: Inverter brands

    Page 4-3 of the Operation guide for the Xantrex XW inverter has a section about motors.
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Inverter brands

    Pretty good guess on that start-up current, eh? ;)

    Good thing you "super-sized" that pump to begin with. Electric motors behave what seems like oddly to most people. Maximum draw is at stall, and even though 746 Watts is one electrical horsepower, it's not the same as "a 1 HP motor uses 746 Watts". In fact I have found that motor spec plates can be quite interesting works of science fiction. :p

    So you have to be able to handle the start-up load of roughly 30 Amps for a fraction of a second. 30 A * 240 V = 7200 W. Fortunately the Xantrex inverters have very good surge handling capability. The XW4024 is rated for 8,000 Watts surge, so it should handle that brief 'blip' on start-up. I think there's enough margin for error there. I could be wrong.
  • RCinFLA
    RCinFLA Solar Expert Posts: 1,484 ✭✭✭✭
    Re: Inverter brands

    If money is tight, get a used 4024.

    Also, check your pump to see if it has option to reconfigure jumpers for 120v.

    Series stacking cable is pretty simple. I threw away the crappy ribbon cable they sell and made my own with data cables. The ribbon is just a reversal using 20 pins of 25 pin connector.

    20 pins of DB25 connector used

    1-> 23
    2 -> 22
    3 -> 21
    4 -> 20
    5 -> 19
    6 -> 18
    7 -> 17
    8 -> 16
    9 -> 15
    10 ->14
    11 -> no connect
    12 -> no connect
    13 -> no connect
    14 -> 10
    15 -> 9
    16 -> 8
    17 -> 7
    18 -> 6
    19 -> 5
    20 -> 4
    21 -> 3
    22 -> 2
    23 -> 1
    24 -> no connect
    25 -> no connect

    pins 11,12,13 and 24,25 are open, unconnected on both connector sides.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Inverter brands

    You probably would have a difficult time doing accurate measurements with a kill-a-watt meter on 1/2 a leg of a 240 VAC split phase load--I would not recommend it.

    Getting on of the whole house meters might be more useful (like a T.E.D. The Energy Detective or such)--However, I don't know how it will respond if the AC is turn on and off all of time (genset, inverter, etc.)--it may loose settings.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    Re: Inverter brands
    jeffkruse wrote: »
    Page 4-3 of the Operation guide for the Xantrex XW inverter has a section about motors.

    Tease.

    (I have your answer here, but you must go to Xantrex and download the manual and look it up for yourself)
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • RCinFLA
    RCinFLA Solar Expert Posts: 1,484 ✭✭✭✭
    Re: Inverter brands

    Measuring the start up surge and its time is a bit tricky to catch accurately. It might be higher then the 28 amps you stated and longer in time. I use a closed loop hall effect sensor with 500 kHz bandwidth captured on a portable digital storage scope.

    The 9.8 amps run current sounds about right for a 2 1/2 hp motor.

    Anything over about 1 1/2 hp likely does not have a 120v/240v wiring option. A single 4024 will not likely start a 2 1/2 hp pump if you put it on a 120/240v transformer.

    The SWplus allows a longer lasting surge then the SW or XW.

    I have two 5548plus series stacked and two 4048 series stacked. The two 5548 runs my central air that has a start current of 120 amps for 400 millsecs, run of 13.5 amps @ 240vac. There is an output voltage slump on 5548+'s when A/C starts. The 4048's run the rest of house including refrig to isolate it from the voltage slump on the 5548+'s when A/C started. Originally with just the two 4048's, the A/C would trip an immediate overload alarm with inverters shutdown.

    LRA spec on a motor does not assure that amperage is not exceeded. It is actually locked rotor amps at lowest operating line voltage spec, typically 208 vac or lower for 240vac motor. Actual startup current for a given setup depends on wire size and length of run to motor. My A/C compress has a spec plate LRA of 105 amps. Actual with my house wiring and line voltage of 240vac mains was 120 amps for 400 millisec.

    I bought an electronic motor soft starter in attempt to get the start current down. Unfortuately, I could cut the peak start amperage by factor of 2 or 3 but only with side effect of a longer surge time for the lower amperage. Most induction motors will draw near LRA until they get very close to syncronous operation rotation speed. Once running the amperage is pretty constant (constant VA)over mechnical load range. Power factor improves as heavier mechanical load is applied.
  • Solar Guppy
    Solar Guppy Solar Expert Posts: 1,989 ✭✭✭
    Re: Inverter brands

    The XW-6048 has a surge rating of 12kw ( 52.5 amps L to L for 15 seconds ) and starts and runs my old and new AC just fine. the old unit was a 4 ton SEER 10 PIG , pulled 4100 watts just running , the new 3 Ton Seer 15 unit pulls about 2700 watts.

    Both run/ran just fine on the XW and I would put this inverter against anything previous or currently on the market. It usually not the inverter that can't handle the surge, its the battery bank or wiring buckling under the load.

    Keep in mind, with the split phase units and being paralleled, you have options to how they turn on the slave units. With surges you would need to back off on the tar savings as they can't instantly respond to the load an inductive motor puts on the inverters.
  • RCinFLA
    RCinFLA Solar Expert Posts: 1,484 ✭✭✭✭
    Re: Inverter brands

    Solar Guppy,

    I am not knocking the XW. It looks to be a fine unit. When my SW's die I will likely go with them.

    BTW, I know the XW gives some DC amperes readouts, but one of the setup's give me the impression that the DC amperage readouts are not direct measurements with a battery line shunt but a calculated number from the AC input voltage and current and inverter AC load measurements.

    Do you know the answer? The only reasons I ask is for lower DC charge currents a direct shunt reading will likely be more accurate then number calculated from AC input and load outputs voltage and current.
  • peakbagger
    peakbagger Solar Expert Posts: 341 ✭✭✭
    Re: Inverter brands

    One thing to consider is to get rid of the pump starting surge by switching to a variable speed drive for the pump motor. They can be programmed for a real slow start so that there is no surge. Some of them also can be fed 110 VAC and they can output 220. Not sure if a capacitor start motor can deal with a drive but it may be worth checking.
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Inverter brands

    To booboo120;

    (Trying to stay focused on-topic)

    The Xantrex 4024 might handle your pump load. If not, a second one could be installed to double the capacity.
    The Xantrex 6048 would definitely handle it, and would reduce the DC current for all loads.

    Since the pump is the biggest thing you've got to run, you probably don't need the extra capacity otherwise. But if you need it for the pump, you need it.

    So, the cost difference between the 4024 and 6048 is only a few hundred dollars. BUT you'd have to re-configure your existing DC system for 48 Volts, and how much would that cost you? Only you can figure that out for sure.
  • booboo120
    booboo120 Registered Users Posts: 12
    Re: Inverter brands

    I appreciate the input but I think we got a little off track with regards to brand advantages vs. disadvantages. I have spent some time on the phone with Xantrek engineering and the reality is that the XW series is wattage at 240 volts with a maximum of up to 75% per leg. So 4000 watts at 120 V equates to 33 Amp However at 120 V you only get 75% max, basically 25 amp. If you take the 4000-watt by 240 Volts then you get 16 amps. Therefore, you have an inefficiency/loss of 9 amps. What this all boils down to is that the SW series is higher efficiency more robust and when being stacked will put out 4000 watts per leg (30 amps) plus a healthy surge capability vs. 3000 watts per leg (25 amps) and that is maxed “no surge left”. The outback stacked is the same way as the SW series stacked except, they are only 3500 watt or 29 amps per leg so for $ 700.00 less per leg you get 4 more amps per leg plus the surge-ability. I need to find another SW and link cable. It appears that the new Xantrex has lost the edge but attempted to make life simpler.
  • Solar Guppy
    Solar Guppy Solar Expert Posts: 1,989 ✭✭✭
    Re: Inverter brands

    The 75% rule is for pulling current from only one leg of the split phase, a very unusual requirement to pull every single watt from only one half of the 240V split phase.

    For a pump load, or any other high current load, should be 240, not 120 to reduce the losses in the wiring.

    In all the cases you make for "stacking" you can do the same with the XW's except the XW's parrallel where is with all the other inverters you need an active second for 240 vac

    If you want or require all the wattage at 120v then with the XW line , then use a cheap X240 ( a 2:1 transformer ) for that pump load , a heck of allot less that a pair of inverters

    A correction to your numbers, You get 75% leg loading on both constant and surge performance ( 15 seconds ) the XW-6048 so its 37.5 amp surge on a single leg.

    Also, the XW doesn't lose efficiency as you say running a single leg, its just the limit of the copper and transformer.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Inverter brands

    The limit to ~75% maximum 240 VAC rating on a 120 VAC leg makes sense from an engineering view point (many internal parts are rated on maximum current--so being power limited on the 120 VAC of a 240 split phase system makes sense).

    You can look at the stacked SW series and say they are limited to 50% of their stacked 240 VAC rating on each 120 VAC leg--so that is not as good as the XW...

    Also, if I understand Solar Guppy's math on the XW 6048 surge capability--it has, at least, 6kW per 120 VAC surge capability per leg (or 12 kW overall).
    52.5 amps L to L for 15 seconds

    I would assume that it would be 52.5 amps L to N also or 6kW surge at 120 VAC.

    But you are looking at the XW 4024--I agree that this is not nearly as cost effective unit as the XW 6048 -- which is about 10-15% more costly for 50% more power capability.

    Still much less costly than a pair of SW 4024 stacked... Unless you find a good deal on a used SW 4024.

    A big issue may be the SW family... Isn't most of the family end of life and little support/service/parts left? (I don't know--just asking).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Solar Guppy
    Solar Guppy Solar Expert Posts: 1,989 ✭✭✭
    Re: Inverter brands

    SW is dead ... only supported by Third Party techs

    Last SW's made in 2003, SW+ I believe 2005 ...

    The cost to service is likely more than 50% the cost of a new XW, shipping those SW's is very expensive and only a handful of people can fix them and some parts can't be found at all ( SW was designed in 1994 )
  • Windsun
    Windsun Solar Expert Posts: 1,164 ✭✭
    Re: Inverter brands

    There used to be a guy in New Mexico that was refurbishing old SW boards and modules, but he is apparently not around any more either.

    So basically what the Guppy said is correct - you will have a hard time getting an SW repaired.
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Inverter brands

    And I thought one of the problems the OP mention was his difficulty in finding an SW - at least one that was a viable prospect. So I sort of went along the lines of "this inverter needs to be replaced". :confused:
  • booboo120
    booboo120 Registered Users Posts: 12
    Re: Inverter brands

    All as I did is repeat what the engineer at Xantrex in BC stated. He agreed that the performance of the stacked SW or Outback’s was better than the paralleled XW’s due to the 120 Volt scenario in North America. I have stated early on that I live on solar so one must bear in mind that the pump is not the only thing that would be drawing power at any given time. That being said one could easily presume that 1 leg or the other of the 220 would be running other equipment when the pump is operating, or is in need of being operated. As to the supposed XW’s rational for 240 volt at 4000 watts; as it was stated by their engineer, the European market is a far larger market and the XW is easily changed via software download to 50 Hz at 220 volt vs. the SW series which were built with a different board change to reconfigure for 50 Hz “his reason for dropping the series”. Also, he stated that the 25 amps +/- is in the maximum surge realm of the XW. The fact again per the Xantrex engineer is the XW series is 4000 watts at 240 volt plus surge capability but at each leg you only get 1500 watts plus surge vs. the SW which is 4000 watts at 120 volts. He also, recommended finding an SW because I would need to step up to the 6048 and even then, it may be questionable without a parallel configuration. It makes perfectly good sense if you look at it from the European market standpoint; remember everything is 220 Volt over there. The transformer would cost another 2%-4% loss in the overall system efficiency. Clearly, from a monetary, installation and operational standpoint, the stacking option is best. One more minor point, the statement of efficiency is semantics “if something is limited to be best suited to a given market only, (best at one thing) then it would have to be inefficient in any other”
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Inverter brands

    I guess I misunderstood the problem. I thought that because you can't get another SW (what with their no longer be supported, much less manufactured) it was a question of what new inverter that you can get will do the job.
    In that respect, the XW 4024 probably will, but might have trouble with the cumulative loads if the pump turns on at the same time. The XW 6048 definitely will, since its surge capacity is 12,000 Watts - well above the expected peak of the pump starting + other draws. The Outback is not a good choice here, because unless I'm reading my configuration manual horribly wrong you will need four $2000 inverters to supply approximately the same load capacity as one $3500 Xantrex.

    75%, 25%, one leg, two, 50 Hz, European market ... does any of that apply when the question really comes down to "will this do the job?"

    The only other thing I'd say is: trust the advice of Solar Guppy, Bill, Niel ... they're not trying to sell you anything from any company. We're all just trying to help. :D
  • booboo120
    booboo120 Registered Users Posts: 12
    Re: Inverter brands

    All the help and advice is much appreciated and I apologize if it sounds as if I am being derogatory. I was trying to clarify that my previous statements came from Xantrex directly, not me! I have been trying to decide the best course of action to update/reconfigure my system is all. In the process it was realized the Xander rationalizations of getting rid of one of the best products on the market (SW series). As per the Xander engineer the 6048 most likely but not the 4024, again the 2-stacked Outbacks would be 3500 watts on each leg of 220 plus the surge so they would be even closer to a no problem situation; plus they would not require re-wiring everything for 48 VDC, which the Bergy windmill won’t allow for anyway. I will start searching for a used SW4024 I have seen them a few times “should have thought about it then” Again, I do appreciate everybody’s input! Thank You all
    Garth
  • Solar Guppy
    Solar Guppy Solar Expert Posts: 1,989 ✭✭✭
    Re: Inverter brands

    When you call the 800 number your not talking with engineers, you talking with phone support which do there best to answer questions, but often get the in depth technical questions wrong. I worked for Xantrex when they were designing and testing the XW-6048, it will do 9kw surge on a single leg as specd, maximum of 75% line imbalance of the surge current 105 * .75 - ~78 amps

    http://www.xantrex.com/web/id/1871/docserve.aspx page 94

    The XW was to replace the SW line, for the US/CA market, the 50hz version hasn't even been out a year yet,

    This power class of inverters realize when you break the 2-2.5kw range the loads this heavy will have to be 240V, not 120V, thats why its split phase. You can pull the full 6kW as 1.5kw/4.5kw, no other inverter on the market can do this and you can gang up to 3 in parallel.

    The US/EU version are not the same, the transformer to run at 50hz is a bit different to deal with the 20% lower volts/second stuff, the electronics are the same sans the firmware.