Please help, is this a solar DC leakage? I am getting shock when touching it while touching the roof

ChanChan Registered Users Posts: 45 ✭✭






Please help, is this a solar DC leakage? I am getting shock when touching it while touching the roof... can I ground the units via a wire + grounding rod to prevent shock?

Comments

  • mike95490mike95490 Solar Expert Posts: 7,249 ✭✭✭✭
    Dry fingers and 12v should not be able to feel any shock.   Is it a "buzz" or a jolt ?  You could be picking up induced AC from nearby power lines.

    Does it happen at night or if you throw a tarp over the panels. ?
    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 ,

  • ChanChan Registered Users Posts: 45 ✭✭
    edited August 25 #3
    it happened around 4pm, not enough sun light.... its a bit of a buzz feeling... painful enough to be felt...

    this is a 300w x 10 series.|

    -- also... touching the aluminum frame does not have any problem.. its touching the edge / rusted part of the panel that is causing the buzz feeling
  • ChanChan Registered Users Posts: 45 ✭✭
    could you check this ... 

    I tried the other parts of the series components from 

    tTthe other strings does not have this problem, could this be an INVERTER PROBLEM, this series is connected to a VOLTRONIC HYBRID INVERTER setup... could the inverter causing this?

    I have tested the other panels which is connected from a different Grid-tie inverter on the same roof... and does not have this problem...
  • mike95490mike95490 Solar Expert Posts: 7,249 ✭✭✭✭
    i see shadows, so you have enough sunlight to get full power from the panels.

    But to feel voltage, you have to complete a electrical path.  Panels have 2 leads, you would have to contact each to feel something,  If you are merely touching the frame and feeling something, I suspect induced AC from local power wires (overhead lines, in wall romex....)
    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 ,

  • BB.BB. Super Moderators Posts: 26,758 admin
    edited August 25 #6
    Each panel is supposed to have its frame grounded to a ground rod via copper wire and approved clamp (or similar approved method).

    It appears that the panel ground is "floating" with respect to the building. It probably does not have to do with the different GT inverters but with the panel frame grounding (or lack of it).

    Note that the aluminum panels are (more than likely) anodized. That is a hard/clear finish that also is a very good insulator. You have to punch through the anodize layer with the sharp tip of your probe to get a good connection. You may have similar poor connection with the rusty roof too.

    Does sound like AC voltage is somehow coupling into the panel frames (very little current). Not dangerous--But does probably indicate poor grounding of the frames/mounting rails.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • ChanChan Registered Users Posts: 45 ✭✭
    edited August 25 #7
    so Should I ground the whole panel via a rod on the building ribars?

    our building structure have rebars protruding on the roof, can I use it as a grounding for my solar panels?

    as for the overhead HIGH VOLTAGE LINE, it as far away as 10-13 meters from the solar panel....
  • mike95490mike95490 Solar Expert Posts: 7,249 ✭✭✭✭
    In Los Angeles, there were high voltage lines along the street, and on dry days, I could get a tingle from the metal trim of my car, from induced voltage from the power lines.
    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 ,

  • BB.BB. Super Moderators Posts: 26,758 admin
    Some of this depends on your local electrical code/standard practices (you are in Philippines?).

    And there are several reasons to ground your solar array.

    First is to reduce the chance of electric shock. You don't want (for example) a short from the +/- PV leads to make the frames "hot", then you touch them when working on the metal roof (both electrocution and fall hazards). The "ground rod" does not really help here--What you want is to ensure that if there is a short to your array frame, it goes back tot the AC neutral (or your DC battery ground if off grid inverter+batteries) to trip a fuse/circuit breaker.

    Another reason is if you are near AC power lines, you don't want a falling power line to energize your array frames with 230 VAC or even 10,000 VAC or higher (local power/distribution lines). You want the grounding to earth and your neutral to green wire bond (at least in the US) to prevent your array (and DC wiring) from becoming hot.

    Yet another reason is for lightning control. You want any lightning hits to go down your ground wire from the array to the ground rod at the base of the wall (short and direct, no sharp bends in the 6 AWG minimum ground cable, etc...).

    In some places (particularly dry ground?), people use UFER grounding--Basically the rebar in the foundations for safety/lightning grounding.

    https://en.wikipedia.org/wiki/Ufer_ground

    There are even other reasons for grounding (prevent 100s-1,000s of volts of static charge on elevated/insulated structures--Again, thunder clouds can cause high static charge voltages), and even to help prevent corrosion from DC bias current--Galvanic corrosion)

    Sorry for the long reply--Grounding is probably one of the more complex subjects for a "simple" grid tie/off grid system install. Add backup genset, issues with lightning/dry earth/etc.... You will have a long discussion here.

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