I think I shorted my panels

miller555miller555 Registered Users Posts: 7 ✭✭
I have 4 320 watt panels running our well pump. At night when we need extra water I disconnect the panels and plug it into 120ac. Last night I forgot to disconnect the solar array before plugging in the ac. Now I have nothing coming from panels. Looks like I might have fried the diodes. Any help would be appreciated.  

Comments

  • NANOcontrolNANOcontrol Registered Users Posts: 215 ✭✭✭
    Lets hope you did fry the diodes.  They are at least replaceable. I replaced a number after a lightning strike and the cells seem to be ok.  I have no idea what you have, but I can't father a PV and AC connection together.  Seems like a really poor design to have that happen.
  • miller555miller555 Registered Users Posts: 7 ✭✭
    I can get continuity over the diodes. So I believe that I did. If I can just replace them and the cells are ok that would be great. Not to bad of a fix. I dont have ac and DC hooked together. I have wanted to get a transfer switch that I can switch between the two but havent got around to that yet. I have a pigtail coming from the pump side of a disconnect box. Disconnect the solar panels manually than plug it into ac. Works great as long as I disconnect panels first. Going to have to get that transfer switch so this dont happen again. Thanks. I will replace diodes and see if that fixes it.
  • Raj174Raj174 Solar Expert Posts: 795 ✭✭✭✭
    Checking the individual panels for voltage and current first might be helpful. 
    4480W PV, MNE175DR-TR, MN Classic 150, Outback Radian GS4048A, Mate3, 51.2V 360AH nominal LiFePO4, Kohler Pro 5.2E genset.
  • miller555miller555 Registered Users Posts: 7 ✭✭
    edited July 2020 #5
    I checked all panels individualy this morning for voltage. Had .9 in all. I know how to check voltage. How do you check current? How do you test a diode?
  • mike95490mike95490 Solar Expert Posts: 9,582 ✭✭✭✭✭
    Pull the diodes off one panel, and then check that panel for voltage with no load , just the volt meter.  Voltage should be close to the Voc listed on the sticker on the panel.   if a couple volt off, no prob.  If no voltage, you likely fried ALL the panels, as they  are really just big diodes.   There is a scheme to melt ice off panels using battery voltage in a controlled manner.  But if you applied grid voltage -ouch.
    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 ,

  • Raj174Raj174 Solar Expert Posts: 795 ✭✭✭✭
    Depends on your meter, some have an AC/DC clamp. Some have a current setting that can measure up to 10 amps with the probes. If the current is higher than 10 amps, which is not likely with most solar panels, the meter input fuse will blow.
    You can test the diode with a resistance test. One side of the diode needs to be disconnected to test. Measure resistance both ways through the diode, positive lead on one side and negative on the other, then swap them. A good diode will read high resistance one direction and low in the other. A bad diode will be open, infinite resistance or shorted, almost no resistance.
    4480W PV, MNE175DR-TR, MN Classic 150, Outback Radian GS4048A, Mate3, 51.2V 360AH nominal LiFePO4, Kohler Pro 5.2E genset.
  • miller555miller555 Registered Users Posts: 7 ✭✭
    Thank you mike and raj. I will try that in the morning. 
  • miller555miller555 Registered Users Posts: 7 ✭✭
    Thank you guys for your help. Finally got to get up their this morning.  Diodes were definitely fried. I removed them and have full voltage.  So looks like I just need to replace the diodes. I definitely wont do that again. Again. Thank you, thank you, thank you
  • miller555miller555 Registered Users Posts: 7 ✭✭
    Does anyone know where I can get the diodes. I've searched online and messaged nws. Also not sure what the numbers mean. Numbers on mine are 
    V2045 M205A
  • mike95490mike95490 Solar Expert Posts: 9,582 ✭✭✭✭✭
    read this article about bypass diodes:
    https://www.digikey.com/en/articles/active-bypass-diodes-improve-solar-panel-efficiency-and-performance
     used to be a https://www.digikey.com/product-detail/en/microsemi-corporation/LX2400ILG/LX2400ILG-ND/2714120
    but they are not stocked.
      Our host may carry some replacements too, check their store.  Otherwise, you are going to need some Schottky diodes, I'd guess 20A 15w  50V should be good enough





    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 ,

  • NANOcontrolNANOcontrol Registered Users Posts: 215 ✭✭✭
    Mine used the TO-220 package like medium power tab transistor.  I robbed mine out of old PC power supplies that I have a lot of. I was kinda shocked that I couldn't fit the screw thru the tab.  I had to drill each one out in order the get the screw thru. I guess when you order hundreds of thousands you can get any hole you want.
  • miller555miller555 Registered Users Posts: 7 ✭✭
    Just an update. Soldered in new diodes this morning and everything works perfect. Thanks again for the help.
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