Grounding panel frames on a RV

emerge411

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Joined
Jul 28, 2021
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11
I have started my install on my RV and got hung up on grounding of the solar panel frames. Initially I was planning on grounding the frames and also using a DC SPD on the positive and negative connection from the panels. I have not seen these connections in any RV based installs I have seen online so I am second guessing myself. Should I remove the highlighted/brighter connections (panel ground and SPD) from my install?

The following doc indicates the frames should be grounded. https://diysolarforum.com/resources/grounding-made-simpler-part-4-mobile-systems.159/

There are only few threads specifically on this topic applied to RVs and they are unclear to me. There seems to be some argument about the need to ground the frames in a system that is grounded to the chassis but not to the actual earth/dirt via a grounding rod or the like. This would be the case when the RV is not connected to AC power which will be often.

I believe NEC would indicate I should ground the frames (Vmax 50v+) but professional solar installs on RVs seem to always skip it.

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FilterGuy

What, me worry?
Joined
Nov 26, 2019
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5,407
Location
Los Gatos CA
I have started my install on my RV and got hung up on grounding of the solar panel frames. Initially I was planning on grounding the frames and also using a DC SPD on the positive and negative connection from the panels. I have not seen these connections in any RV based installs I have seen online so I am second guessing myself. Should I remove the highlighted/brighter connections (panel ground and SPD) from my install?

The following doc indicates the frames should be grounded. https://diysolarforum.com/resources/grounding-made-simpler-part-4-mobile-systems.159/

There are only few threads specifically on this topic applied to RVs and they are unclear to me. There seems to be some argument about the need to ground the frames in a system that is grounded to the chassis but not to the actual earth/dirt via a grounding rod or the like. This would be the case when the RV is not connected to AC power which will be often.

I believe NEC would indicate I should ground the frames (Vmax 50v+) but professional solar installs on RVs seem to always skip it.

View attachment 73677
I highly recommend you ground the frames to the chassis. When driving the airflow can create static charges that should be dissipated if at all possible.

There are a few options on grounding the frames.

If the mounting method is all metal and naturally connects the frames to the chassis, then make sure it is a good connection and call it good. Any additional grounding wires would almost certainly create ground loops. (Notice that with this, the frames are grounded to the chassis but there are no obvious grounding wires.)

If the mounting method does not electrically connect the frames to the chassis, then grounding should be added. The grounding can either go directly to the chassis or go to your common DC negative and then to the chassis. (Do not do both because it might create a ground loop).
 

FilterGuy

What, me worry?
Joined
Nov 26, 2019
Messages
5,407
Location
Los Gatos CA
I highly recommend you ground the frames to the chassis. When driving the airflow can create static charges that should be dissipated if at all possible.

There are a few options on grounding the frames.

If the mounting method is all metal and naturally connects the frames to the chassis, then make sure it is a good connection and call it good. Any additional grounding wires would almost certainly create ground loops. (Notice that with this, the frames are grounded to the chassis but there are no obvious grounding wires.)

If the mounting method does not electrically connect the frames to the chassis, then grounding should be added. The grounding can either go directly to the chassis or go to your common DC negative and then to the chassis. (Do not do both because it might create a ground loop).
Just to be clear. The system may never have a problem if the frames are not grounded..... but I figure that it is easy enough to ground them so why take a chance.
 
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