Solar Photovoltaic (PV) Systems, Grounding Electrode System, NEC 2020 - [690.47], (9min:30sec)

How do you properly ground a building’s solar photovoltaic (PV) system? It’s not as difficult as you might think. Take a moment to read the text and watch the video where Mike and the PV team explain NEC section 690.47.
This video is extracted from Mike Holt's 2020 Solar Photovoltaic Systems Video Library, for more information visit www.MikeHolt.com/Solar or call 888.632.2633.
For almost 50 years, Mike Holt Enterprises has been providing quality electrical Code training to help electrical professionals learn the Code, prepare for exams, and improve their electrical knowledge. Visit www.MikeHolt.com​ for exam preparation tips and training, instructor and curriculum support, continuing education options, free videos, and graphics, and so much more.

[@FrancisKoczur]

Residential transformerless inverters that aren't grounded to neutral have been the standard for a decade. No need for confusing language in the code. Grounded and ungrounded transformer inverters still have their place, but referencing to them isn't necessary. Keep up the good work.

[@vassilnikov6814]

What about when the array is on a the roof of a separate building more than 20 meters away from the main building? How do we install SPD devices in such configuration? If the cable trace is that long wouldn't it be inefficient to install the SPD at the box in the main building only? Wouldn't in such case a separate grounding rod and SPD at the separate building with the array be a preferred option?

[@gfjardim1983]

You can put an auxiliary grounding electrode on the PV array, but the SPD devices should be in your PV combiner box inside your main building, and its grounding wire have to be bounded at the main panel grounding bar.

[@christopherworks400]

I work in solar and I got in an argument with the "electrician" that ground rods are Required by code for ground mount array, even though the metal support was driven in the ground 8 feet. And on top of that he said we need 2. So am I right that they ARE NOT required?

[@TheTubejunky]

Most inspectors say 2 rods. Idk who's right anymore. every engineering line drawing I've seen SHARES a common service ground. That should be all that's needed. You would think right?

[@christopherworks400]

@@TheTubejunky well there was 2 rods for the house, but they wanted 2 more for the array. so there would be 4 total.

[@kimandylawrence4199]

Yes, you are right. They are not required.

[@captainjohnmccalpin5161]

What about grounding requirements for a stand-alone (off-grid) PV system installed in a floating boathouse (covered metal dock on plastic floats, not a houseboat)? There is no utility connection with a grounded service disconnect. What do I need to do to provide a compliant ground for panels, inverter, stand-alone load center, etc.?

[@MikeHoltNEC]

Please send me an email, [e-mail], with this question so I can work this out.

[@captainjohnmccalpin5161]

Will do!

[@georgevan3102]

What about a line tap pv system. It does not have a ground conductor. Where do you pick up the grounding?

[@christopherworks400]

we crimp on the the ground coming out of the house and add a second rod.

[@georgevan3102]

@@christopherworks400 250.142 have you ever taken this in to consideration?

[@kevinthompson4690]

Same here. We were doing small cell 5G sites with 8x8x 12 foot deep concrete encased steel reinforced pole bases with a #2 tinned copper wire attached to the rebar out of the concrete. Ole inspector walks up and says "Wheres your ground rod? gotta have a ground rod". I said really? You think that a 5/8x 8 foot ground rod is required and is gonna do anything? Non educated is what they are.

[@WiSeNhEiMeR-1369]

now explain how to adapt this too a GROUND-MOUNT Arrays 300' from the House Wiring SYSTEM ... ...

[@MikeHoltNEC]

Nothing (grounding) is required at all, so you are good.