Some help tweaking an XW6048

I am wondering if I have things really set up correctly on the Xantrex XW6048.

I am never seeing any "Load" on the display screen. Now, I know that the inverter is putting out power, I can see that on the electric meter. I can also see on the little display screen of the System Control Panel that energy is going from the battery to the grid.

I am using it as grid tied, so it is my understanding that both incoming (from the grid) and outgoing (from the solar charged batteries) electricity are using the same breaker. That is a 40 amp breaker, and it is on the XW6048 AC1 in line.

The AC1 out line is connected to a subpanel that is fed from the grid when electricity is available, and manually switched to the XW6048 when the grid is down. In the setup drawings it shows an isolated subpanel which is supplied from the XW6048.

Also, I can't figure out how "Load Shave" would work when I can't see any load in the first place.

And it seems that if I turn "Sell" off everything stops.

The booklet says that you can "Load Shave" without doing "Sell."

Are all of these things only available if you have an isolated subpanel supplied from the XW6048? But then the instructions that you can "Load Shave" without "Selling" are confusing to me. Would you only "Load Shave" on AC1 out, and only "Sell" on AC1 in?

Comments

  • Solar GuppySolar Guppy Solar Expert Posts: 1,989 ✭✭✭
    Re: Some help tweaking an XW6048

    If there is nothing connected to AC1 out, there can't be any "load" or shaving as there is no load!

    Selling is "back feeding" via AC1 in

    On my system, I have the Air Conditioner and Air Handler connected to AC1 out, so when the AC running you can see the amount of energy that is being split between the load and selling, when just selling the total watts in the system screen is what is being sold

    Also manual calls for 60 amp breakers as that is what the built in transfer is rated for and needed to meet the XW-6048's surge rating, you 40 amp is to small.
  • sub3marathonmansub3marathonman Solar Expert Posts: 300 ✭✭✭
    Re: Some help tweaking an XW6048

    As usual, the help from Solar Guppy is much appreciated. It is pretty much what I started thinking, but it helps to have an expert confirm it.
    If there is nothing connected to AC1 out, there can't be any "load" or shaving as there is no load!

    Selling is "back feeding" via AC1 in

    On my system, I have the Air Conditioner and Air Handler connected to AC1 out, so when the AC running you can see the amount of energy that is being split between the load and selling, when just selling the total watts in the system screen is what is being sold

    Also manual calls for 60 amp breakers as that is what the built in transfer is rated for and needed to meet the XW-6048's surge rating, you 40 amp is to small.

    I originally thought that anything in the house that needed electricity was a "load," and that somehow the inverter could sense that. Somewhat like backpressure in a hose, when the pressure dropped the inverter responded.

    The 40 amp breaker is all that is allowed because of the main panel at 200 amps and the NEC allowing 20% more. So that allowed a maximum 40 amp breaker. There is a section in the configurations that allows manually setting the size of the AC1 breaker, which I changed to set at 40 amps. I saw that by doing it this way the XW6048 "limits the maximum input current to this setting by derating its charging current." But I figured that since it was connected to the main panel supplied by the grid there wouldn't be a need for a 12kw surge, and also my PV setup of 4.7 kw wouldn't be able to supply more than 40 amps anyway.
  • RCinFLARCinFLA Solar Expert Posts: 1,482 ✭✭✭✭
    Re: Some help tweaking an XW6048

    Sounds like you have a weird setup. Are you doing it because you have small batteries connected?

    When you say you can only put a 40 amp breaker feeding to XW I assume this is because you still have everything possibly powered from main panel.

    Generally you want to break stuff out that you want to run on XW when grid is down and feed from breakers in the aux box. This relieves breaker loads on main box and transfers them to aux box. The main panel feeds the XW AC1 in via 60 amp breaker and XW out feeds the aux panel.
  • sub3marathonmansub3marathonman Solar Expert Posts: 300 ✭✭✭
    Re: Some help tweaking an XW6048
    RCinFLA wrote: »
    Sounds like you have a weird setup.



    Well, yes, there's another story to that.

    When the house was being built, I kept asking about 300 amp service. I kept being told that I only needed 200 amp service. Now, it is my understanding that 300 amp service requires a larger cable and the local electric company thus charges a relatively high installation fee, but I wasn't even given that option.

    So now I have run into what seems to be a relatively common occurrance with PV installations, the 20% NEC rule. Now, it was pure luck, not skill, that I was trying to get the 300 amp service, which then of course would have allowed perfectly for the 60 amp breaker as is called for. But now I'm stuck with the 200 amp service and the 40 amp breaker. I don't know if I could drop the main breaker back to a 180 amp breaker, but that seems like a lot of additional work too for a questionable gain.

    And yes, there are actually two additional subpanels. I tried to set up things with the thought of a "critical loads" subpanel, which is supplied either from the grid or via a manual transfer switch through the PV system. I have just left that subpanel as it was, supplied by the grid, since the grid is still up and I am backfeeding the grid anyway. The other subpanel is more circuits for the house that wouldn't fit on the main panel.

    I still wonder if 200 amp service is really correct for the loads that this house has. I never could get a calculation sheet from the electrician, and although it did pass inspection I still wonder, since in our previous house we discovered that the master bathroom wasn't GFCI protected yet it passed inspection.
  • RCinFLARCinFLA Solar Expert Posts: 1,482 ✭✭✭✭
    Re: Some help tweaking an XW6048

    Unless you have a mansion with multiple large air conditioners and electric tankless water heaters, I cannot imagine needing more then a 200 amp service.

    Power company doesn't like putting larger then 2/0 to residential houses.

    How many kWH do you consume a month?

    I'm not an NEC expert but if you have legit transfer switches between main box and Aux boxes on output of XW you should have a case that simultaneous loads can not happen on the main panel allowing a 60 amp breaker to XW input.

    I have 60 amp breaker and only 150 amp service main panel
  • halfcrazyhalfcrazy Solar Expert Posts: 720 ✭✭✭
    Re: Some help tweaking an XW6048

    Can you change the Main breaker to something smaller say 150amp? thus allowing you the 60 amp breaker.
  • BrockBrock Solar Expert Posts: 639 ✭✭✭✭
    Re: Some help tweaking an XW6048

    I am confused as to why the "critical load" sub panel is on a manual transfer switch? The XW has an automatic transfer switch and does it either way without missing much in the transfer. As RC noted, unless you have a small battery bank I don't know why you wouldn't let the XW do the switching automatically.

    Our XW is fed from our main 200A panel with a 60 amp breaker, then pretty much everything else is in the sub panel which is actually an identical 200 amp panel to the main panel and is fed from the XW AC1 out. I know I probably have more than I should on the XW circuit wise, but if I hit 2kw on the load side it is high, typically I am consuming about 700w on the load side.
    3kw solar PV, 4 LiFePO4 100a, xw 6048, Honda eu2000i, iota DLS-54-13, Tesla 3, Leaf, Volt, 4 ton horizontal geothermal, grid tied - Green Bay, WI
  • tallgirltallgirl Solar Expert Posts: 413 ✭✭
    Re: Some help tweaking an XW6048
    Brock wrote: »
    Our XW is fed from our main 200A panel with a 60 amp breaker, then pretty much everything else is in the sub panel which is actually an identical 200 amp panel to the main panel and is fed from the XW AC1 out. I know I probably have more than I should on the XW circuit wise, but if I hit 2kw on the load side it is high, typically I am consuming about 700w on the load side.

    Usually you're safe with load diversity, but too much base load makes for poor performance in the event of a transient peak, such as a motor getting started. Or the microwave.
  • RCinFLARCinFLA Solar Expert Posts: 1,482 ✭✭✭✭
    Re: Some help tweaking an XW6048

    One thing I did learned the hard way is to have an inverter bypass switch. When lightning hit the mains it blew the small voltage sense transformer in my SW4048 so it thought there was no A.C. mains and stayed on battery power.

    Of course it happened when I was on a business trip so my wife was instructed to 'conserve' consumption until I got back. You should have seen me in a hotel room going through the pdf manual on my laptop trying to walk my wife through a debug on the phone.

    Now if anything goes wrong she knows to hit the bypass switch and possibly the battery main switch if there is any smoke coming from the inverters.
  • Solar GuppySolar Guppy Solar Expert Posts: 1,989 ✭✭✭
    Re: Some help tweaking an XW6048

    I think Sub3 got the 60 amp bypass mixed up with the back feed rule. The XW will never sell back more than ~30 amps ... the 60 amps is what the load surge, not backfeed rating is of the XW and 60 amps is the actual transfer relay rating.
  • sub3marathonmansub3marathonman Solar Expert Posts: 300 ✭✭✭
    Re: Some help tweaking an XW6048
    Also manual calls for 60 amp breakers as that is what the built in transfer is rated for and needed to meet the XW-6048's surge rating, you 40 amp is to small.

    Yes, once again Solar Guppy has it figured out. I'm STILL trying, but remain a bit (less now though) confused. :confused:

    Yes, the three breakers in the XW Power Distribution Panel are 60 amps as called for. The one backfeed breaker in the main panel is 40 amps, which is what I understand to be the maximum because of the 20% rule. I don't know how Brock can have a 200 amp main panel with a 60 amp breaker supplying his XW.

    I also did change the manual transfer switch on the subpanel over to the AC1 line, as was suggested, and sure enough, there's the LOAD showing up!! I'm not sure of the technical details of the path the electricity goes for this setup vs. backfeeding the main panel which then supplies the subpanel. I understand though that now the subpanel will not suffer from any grid power outage, it will continue to be supplied by the batteries.
  • Solar GuppySolar Guppy Solar Expert Posts: 1,989 ✭✭✭
    Re: Some help tweaking an XW6048

    Sub3,

    The panel should have 60 amps, not 40 if you want the load side of the XW to have the 12kw rating.

    For the back feed requirement, that's meet by the software in the XW, it limits the back feed to 6kw maximum ( 30 amps ) and that is what is used for the back feed calculation for the main breaker panel, not the 60 amps.

    The confusion is straight GT inverters only sell energy, the XW can have power flow in both directions, for Sell its 30 amps, for load support, its 60 amps.
  • sub3marathonmansub3marathonman Solar Expert Posts: 300 ✭✭✭
    Re: Some help tweaking an XW6048

    Now, I didn't know that either. I didn't read that in any of the literature either, although maybe if I did read it I didn't understand it.

    So, there can be a 60 amp breaker, because at most the XW will backfeed 30 amps. But is that also accepted by the NEC?

    Also, it can do 60 amps for load support, but only for at most 10 seconds, if I understand that correctly. I guess if the load is higher than that the inverter will shut off?
  • BB.BB. Super Moderators, Administrators Posts: 33,319 admin
    Re: Some help tweaking an XW6048

    SG will give you the exact answer...

    But, remember fuses protect wiring and connections. You can have a GT and the support wiring that allows the use of 60 amp breakers (or smaller)--Even though the maximum backfeed would only need a 30 amp breaker.

    In this case the 12 kW surge is "non-trivial" (more than just a few cycles to start a motor) that is passed onto the load (through the transfer switch). So--if you need 60 amps -- then you should wire for sixty amps.

    You potentially also have the condition where you are just recovering from a power outage... You have a heavy load (30 amps for AC and what not), the AC mains come back on--and now the inverter is drawing 60 amps pass through for the load, and another XX amps for recharging the battery bank (if you have configured the internal charger for this function)--So, again, you could use more than the 30 amps--but again as a load--not as a generation source (which hits the Box's overall 120% design limit).

    The XW Hybrid inverter is a wonderfully flexible unit--but it does insert complexities that are not obvious to somebody trying to fit Box A into Code 34.56 subsection C.2 -- without a lot of study and understanding.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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