Metal Solar Rack Energized

[bikerider4818]

I have 10 X 400 watt bifacial solar panels mounted to a metal rack/frame which is mounted to the top of my wood framed patio. The panels are wired to my EG4 6500ex inverter (I have one inverter only). Everything is working perfectly, but in the afternoon, while the system was running, I was on my aluminum ladder which was leaning against my aluminum rain gutter while I was up looking at the wires under the solar panels. I leaned forward and put my hand on one of the rails of the metal rack and it buzzed my hand and arm pretty good. It wasn't a strong shock, more of the vibrating buzz that makes your hand and forearm feel a little numb and tingle. I wasn't sure what I was feeling so I actually put my hand on it a second time and felt it again. Ha Ha. Is this common? What is causing this? There are no exposed or damaged solar wires and My neighborhood does not have overhead electrical wires of any kind. I do NOT have my panels and rack grounded to a grounding rod. Would putting in an 8' ground rod and 6 gauge grounding wire fix this? Is it okay to put in a new rod next to one of my patio posts and run the grounding wire to it. Or does it have to go all the way back to my house ground rod that's under my meter? I'm not sure how I would even get it to my house grounding rod. Not sure if that's even possible. I also noticed that one of my water lines outside has a ground clamped to it. Can I ground my solar array to one of my water lines/hose bibs outside?
Thanks for your help.

 

[Adam De Lay]

I had the exact same issue with my wooden ground mounts. I believe someone told me that the issue is common on cheaper HF inverters because there's no isolation between the AC and PV. A lot of it was way above my head other than the fact that I could hear a static like noise when I put my finger close to my panels.

I put a meter on the panels and I was getting up to 170V AC on the panels. Current was almost non-existent, just higher voltage.

I believe code states that you're supposed to ground the panels back to the main ground of the house.

 

[zanydroid]

(US perspective)

I think the safest thing to do here is ground everything to the same ground as the house, that has the most likely chance of doing what you want. Most people (99% of the human population) don’t understand grounding well enough to understand the implications of deviating from from local code.

For instance if you just drive in ground rods, there is zero guarantee that the ground fault detection in your inverter will work correctly, and it’s easy for a stronger fault to still pull the voltage up to 100V+ . Just because the ground rod is pushed into something called the ground (in English), doesn’t mean it is at what you want ground potential to be at your house. Physics doesn’t care about what things are called

 

[marksrig]

DO NOT ground your panels to the negative PV
DO run a ground from the panels back to the main panel ground. This is for not only static build up and fault protection, but will eliminate the AC output from the inverters you're feeling. I had the same thing happen and the manual does warn to only work on the system unenergized although they don't mention about the output on the PV input.
The closer you can get your grounds to 0 Ohms the better.