Micro inverters in parallel

Thomas

Hi, I just hooked up my 8 230 watt panels to 8 Enecsys microinverters and then to my box with a 240/15A breaker.  Moving my entire DC inverting out of doors.  All good, great simple...but...
I have 2 more 12v panels 215 watts each I want to use.
So I hooked up the series 12v to parallel inverters and they both worked fine.
some problems installing the rest, worked thru with e-bay seller, returning to continue installation... and now only one of the 2 inverters [in series/parallel]checks in with the wireless zigbee gateway, along with all the rest.
does not matter which I disconnect/ reconnect only one inverter will work at a time. with both panels in series.  I am worried that when the power reaches full next season that the one inverter will go out, because the power will be 430Watts @ 24VDC, and the single inverter is only rated at 240Watts[well 260DC] but when both panels are at full the output will be over and the other inverter in parallel is not checking in with zigbee gateway anymore?
It is a Enecsys Gen1 system I bought on e-bay, all went good except for the series panels.

inetdog

Because of the way that an MPPT algorithm may be implemented, it is never a good idea to parallel two MPPT devices to a common panel or string of panels.
That may not account for your specific symptoms, but it is a configuration to avoid.

bill von novak

Thomas said:

So I hooked up the series 12v to parallel inverters and they both worked fine.

Don't do that. 

In general, well designed inverters will not be damaged by having too much power available.  As long as voltage is kept within the inverter's input limits, you shouldn't have a problem; the inverter will limit itself.

Thomas

      Thee specs are 20-42 vdc and 260 watts. input.  my two 12v panels total 44vdc[open circuit] and  215 watts apiece. [430 watts] input.
You think I should hook up both to one inverter.  I may not get all watts from both panels[when available]  Your right though, I think the inverters save themselves by simply not putting out any excess power, [which is possible with solar, but wind].
I am really not too concerned about max. MPPT.  These inverters are so far head&heels better than the Asian grid ties I just had for a few years.  A jump from 85 to 95 percent is very noticeable ...at the meter .even in the winter.
I believe that both of the inverters in parallel are functioning, when isolated they each work, and when isolated from the other 8  both seem to be combining.
     I was just wondering if there may be anything special about the the communication electronics and series supply... I am running a myriad of inexpensive panels, Amerisolar[5] Lightway, MXSolar, Hanwa,[and the 2 Evergreen 12v panels.
Outside of that I have one more problem with one more inverter not communicating with the gateway.
     I think that the communication power requirements might be tight.  I checked all of the power out and all of the inverters are getting DC.  So now I have to isolate the one that is not communicating with the gateway.[time consuming task]
I believe that all the inverters are functioning though, only not communicating with the gateway.  I do not have the equipment to check this though, or the time to check each one against my meter![like I did with the 12v panels]
     Electronically maybee the series Evergreen supply, or the supply from the MXsolar/ Hanwa are out of bounds.[for communication enablement] [ Equipment or technical know how to dicsover] I do not know what the installer specs were for these inverters.  I do know that the inverters function without the gateway.  It takes a few  whole minutes for the inverters to start working after I throw the breaker.
So barring any obvoius answer the remaining questions are just too time consuming and not worth it in the winter. 
I might just connect the series panels to one inverter, the wattage will not go above limits for a while.

Thomas

here is my aloaha output in AC, dc is proportionally different.  One of there inverters is the one working in parallel of two.  The one connected in parallel with the one working is not listed.
http://www.dataservices.solar/SolarWeb/PowerGauge.aspx?sn=2000015586

Thomas

One was broken.  All 10 now working....the seller sent me one extra, good thing!