installing 9 panels

2»

Comments

  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: installing 9 panels
    castilloj wrote: »
    what voltage should i get from one string of 3?

    Three times the Voltage rating (Vmp and Voc) of a single panel.
    And since I haven't reviewed the whole thread check to make sure the 3X Voc does not exceed the input maximum of the controller.

    For example if these are 35 Vmp panels that have a Voc of 43 then three in series would be Vmp 105 and Voc 129. Those numbers would increase in cold temperatures, meaning that such a combination would not work on a typical MPPT controller with 150 Volt input limit in a cold climate as the Voc would exceed the maximum.

    If there's any doubt, lower the Voltage by using only two in series (Vmp must be at or above minimum needed for system charging) and either buy a tenth panel or sell the ninth. No one wants a fried charge controller or one that shuts down every morning!
  • castillojcastilloj Solar Expert Posts: 208
    Re: installing 9 panels

    This is what it says on the label of panel.Attachment not found.
  • castillojcastilloj Solar Expert Posts: 208
    Re: installing 9 panels

    Attachment not found.

    What can i do about this?
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: installing 9 panels
    castilloj wrote: »
    Attachment not found.

    What can i do about this?

    What are we seeing there? (Between my small screen an aged eyes images aren't that clear.)
    If it's something on the glass you try to identify it and remove it, using as gentle method as possible.
    If it's a break in the glass (almost looks like it got hit with a stone?) you have a problem as the glass is not really reparable.

    Then there is the question of if this is a warranty issue or not: did it come that way? Shipping liability?

    If the answer is you won't get someone else to pay for it and can't afford a new panel (rest assured damaged glass will result in failure eventually) you seal it up as best you can. There have been a few discussions about how best to do this on the forum. None are exactly perfect.

    I wonder if anyone has tried an auto glass place to do a crack repair like they do for windshields?
  • castillojcastilloj Solar Expert Posts: 208
    Re: installing 9 panels

    so i just tested Voltage on broken Panel. I get 32.7 on good panel and i get 32.4 on broken one.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: installing 9 panels
    castilloj wrote: »
    so i just tested Voltage on broken Panel. I get 32.7 on good panel and i get 32.4 on broken one.

    That would be Voc and within the realm of error.
    Now try testing the Isc and see what you get; that is more important.
  • castillojcastilloj Solar Expert Posts: 208
    Re: installing 9 panels

    Ok on good panels im getting 6.80 amps
    And on the cracked one 4.43 amps
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: installing 9 panels
    castilloj wrote: »
    Ok on good panels im getting 6.80 amps
    And on the cracked one 4.43 amps

    Assuming the testing was done right (full sun direct on panels, measure individually into short circuit) that indicates that panel has a problem. 35% current drop; one segment of the panel is dead (no doubt due to that one cell being smashed) and the current from the other 2/3 is passing through the bypass diode. I'd advise against using it.
  • castillojcastilloj Solar Expert Posts: 208
    Re: installing 9 panels

    So i guess i have no choice than connect them in series of 2x2x2x2 for 24 v?
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: installing 9 panels
    castilloj wrote: »
    So i guess i have no choice than connect them in series of 2x2x2x2 for 24 v?

    I don't know what that means.
    Four parallel strings of two in series?
  • castillojcastilloj Solar Expert Posts: 208
    Re: installing 9 panels

    yes , thats what it means. Sorry about that.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: installing 9 panels
    castilloj wrote: »
    yes , thats what it means. Sorry about that.

    Right. If you're down one panel from 9 that's the way to do it.

    Sorry but I have trouble keeping track of everybody's system. Gettin' old I guess.
  • castillojcastilloj Solar Expert Posts: 208
    Re: installing 9 panels

    Thanks for your input. I really appreciate all you do to guide us in the right direction.
  • castillojcastilloj Solar Expert Posts: 208
    hey guys ,i was checking my MPPT today and with the 8 sonaly panels
    My array Voltage at 11:40 am is -64.12 v
    sweep pmax-542W
    sweep VMP-31.82
    sweep VOC-42.43
  • SurfpathSurfpath Solar Expert Posts: 393 ✭✭✭
    castilloj wrote: »
    hey guys ,i was checking my MPPT today and with the 8 sonaly panels
    My array Voltage at 11:40 am is -64.12 v
    sweep pmax-542W
    sweep VMP-31.82
    sweep VOC-42.43

    Hi-seems to be normal for that time of day (Puerto Rico, an hour or so into absorb right?). 43 VOC is fine for a 24v bank, VMP looks good too, should be around 1.20-1.3 the size of your nominal battery voltage. The real question...Have your SG's been up to snuff? Which battery did you end up with?

    I will install a series of that same Sonali panel this summer. How are yours holding up. Do they seem well built?
    Outback Flexpower 1 (FM80, VFX3048E-230v, Mate, FlexNetDC) 2,730watts of "Grid-type" PV, 370 AmpHrs Trojan RE-B's, Honda 2000 watt genny, 100% off grid.
  • BB.BB. Super Moderators, Administrators Posts: 30,485 admin
    Do you have two panels in series? Are the Vmp/Voc of the array cut by 1/2 for the panel Vmp/Voc numbers above? 64 volts Vmp-array would indicate two panels in series.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • castillojcastilloj Solar Expert Posts: 208
    Yes i have them installed 2 in series.
Sign In or Register to comment.