This can cause issues to upstream GFCI breakers like in an RV park shore power outlet. EMI filters on AC input and AC output of inverter have small capacitors that are connected to inverter case that can leak 5 to 10 mA of AC current to inverter metal case. Should have greater than 200k of resistance. You can check this on each panel with an ohm meter from each panel power lead and frame of PV panel. Your PV panels can develop leakage resistance path from flat wire PV cell interconnecting strips within panel and the PV panel frame due to humidity intrusion near the edges of front glass to backing plastic lamination seal. This gave way to the polarized AC cords where the wider flat prong of AC plug was always neutral of AC.īeside items described in above thread, there are a couple of other things that can cause leakage to ground. After the plastic knob broke off you had a good chance of getting shocked by attempting to adjust the brass shaft. This can range from just non-optimum MPPT point resulting is less PV power yield to damaging SCC MPPT controller or inverter if leakage is bad enough.Īll this is similar to the 50's and 60's days of transformer-less radios and TV's. PV panel frame edge leakage described above can screw up AIO inverter's SCC MPPT controller. If you accidentally or intentionally ground the PV- or PV+ inputs while inverter AC output is active you can blow out the HF AIO inverter's sinewave PWM IGBT H-bridge devices. When Will blew the DVM 10 amp fuse, that is due to the lack of isolation between PV input and AC output of inverter and is described in above thread link. Should have greater than 200K ohms of resistance.ĮMI filters on AC input and AC output of inverter have small capacitors that are connected to inverter case that can leak 5 to 10 mA of AC current to inverter metal case. So we have some competence in this space, for better or worse.īeside items described in above thread, there are a couple of other things that can cause leakage to ground. Does anybody have any idea of what could be going on?īoth my father and I are electrical engineers, btw. I've seen a few references to people being shocked on the frames or perhaps AC induction from grid sources, but nothing that quite matches with this scenario. There must be some sort of stray AC voltage getting onto the DC side of the inverter. On the AC side, the LV6548 is the location of our neutral-ground bond, with the bonding screw removed from the main power panel where the ground from a separate ground rod is referenced. So apparently they are picking up AC induction from the in-use PV wires - which still doesn't answer why the frames were somehow energized at one point or why AC is present in the first place. There is no grid power anywhere near the house or array or anything else in the conduit with the PV wires. These are in the same conduit as the active wire runs for ~80 feet. However, the unused and unterminated wire runs (#10 THWN) that will in the future be connected to the other strings have also since delivered the same shock, and are also registering an AC voltage. ![]() He has since installed a ground rod at the array location and connected the frames to it, which has allowed that stray voltage on the frames to go away. ![]() While doing work around the panels shortly after installing them and connecting them for the first time, my father noticed he was getting a light to moderate shock from the frames of the panels, and from what I understand the frame registered an AC voltage to ground on the multimeter (~50-60V from what I am told). At the moment, only one inverter has been installed and is operating, with 2 of the strings feeding each of its CCs. These are setup as 4 individual strings (~190Voc, 10A), eventually feeding 2 LV6548 MPP Solar inverters in a split phase setup. I am helping my father install a 16 panel 6.4kW off grid ground mount system at his house in the Bahamas.
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