Missing ground wire on PS2 schematic

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Kent Osterberg
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Missing ground wire on PS2 schematic

Post by Kent Osterberg » Fri Apr 23, 2004 7:50 pm

We might need a subcatagory under integration products just for the PS2.

On the schematic for the PS2 there is a missing ground wire from the dc grounding bus to the pv array. Any grounding system installed at the pv array must be connected to the main dc ground.

This portion of the schmematic should be like the PSDC schematic.

Is there a drawing that shows the location of the KOs on the PS2 DC? Thanks.

Scott Payne

Missing ground wire on PS2 schematic

Post by Scott Payne » Mon Apr 26, 2004 2:11 pm

Kent, you are correct. Technically all ground rods must be tied together. I have Robin change that.

I'll make a new category tonight for the PS2.

Thanks,

Scott

<small>[ April 26, 2004, 04:13 PM: Message edited by: Scott Payne ]</small>

DavidB
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Missing ground wire on PS2 schematic

Post by DavidB » Mon Apr 26, 2004 5:48 pm

My array mounting structure is over 200 feet from the house in sandy soil. I question whether it would be a good idea to bring a ground wire all the way back to the house from that location.

Kent Osterberg
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Missing ground wire on PS2 schematic

Post by Kent Osterberg » Fri Apr 30, 2004 11:52 am

David,

I think that you always need to include a grounding wire with pv array conductors. If the array is on a separate stucture, it'll need a grounding system too. The NEC allows structures to be a separately derived system if there is no conducting paths between the stuctures. This means no grounding conductor to structure, but a new bond between neutral and ground is required. This option is okay for ac power but should never be used with dc power. The small potential drop in the grounded conductor means that the grounding systems would be at a slightly different potential. That causes DC current to flow in the earth. On one end the current will eat away the ground and and steel structure. Not long ago Homepower had a photograph of a wind generator tower that fell because the grounded conductor was connected to the tower leg! A separate ground wire would have prevent that from happening.

Kent

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