[RE-wrenches] Sol-Ark 15k solar panel frame grounding

[William Miller]

Friends:



On a related subject, I was researching the question: What color should my
grounded PV conductor be?



History:



In the beginning, negative leads were always black.



When it became apparent that negative PV leads were indeed grounded, the
requirement to have them white or grey became enforced per 200.6(A)(3).



When transformerless inverters were implemented it was assumed the negative
was floating, so white/grey was no longer acceptable.



Then the NEC recognized that some leads were kind of grounded, not solidly,
but through some components, either OCPD, resistors, sensor or a
combination.  A new term was created,  functionally grounded.  This
grounding was most often done to implement ground fault detection and
interruption, or GFDI.  I always assumed that if PV equipment had GFDI it
had to feature a grounded polarity, most often indirectly, or functionally.



Grounded conductors need to be white or grey.  Therefore we are back to
needing grey/white, most often for the negative lead.



I wanted to verify if the Sol-Arc PV inputs established a grounded lead.
They have GFDI so I assumed it likely they did.  In order to verify, I
called Sol-Arc.  Their tech support had no idea what I was talking about.
They did not know the term functionally grounded and could not verify if
their equipment established a ground connection, solid or otherwise, to
either polarity.



This distinction applies here because it may help determine what is causing
the GFDI fault.  I can’t tell you for sure if one side of the PV circuit is
functionally grounded, but if it is, grounding it elsewhere will defeat the
GFDI and may cause nuisance tripping.



Does anyone know if Sol-Arc PV inputs have a functional ground bond?



Side note:  I called my local Greentech distributor, who sells plenty of
Sol-Arc inverters and asked if they carried white PV wire.  They said none
of their customers are asking for white PV wire.  I suspect they should be
using white for negative leads.  I can’t confirm that because Sol-Arc can’t
tell me it the PV circuits are functionally grounded or not.  Frustrating!



Fortunately the manual for Outback charge controllers specifically says the
negative lead is functionally grounded.  So if you are installing Outback
CCs you must use white or grey.  PV-Cables sells white PV wire.



Confusing?  Yeah, a bit.  But as my local roofing companies say:  “Solar?
It can’t be that complicated!”



William Miller



Miller Solar

17395 Oak Road, Atascadero, CA 93422

805-438-5600

www.millersolar.com

CA Lic. 773985





*From:* RE-wrenches [mailto:re-wrenches-bounces at lists.re-wrenches.org] *On
Behalf Of *Jason Szumlanski via RE-wrenches
*Sent:* Wednesday, June 5, 2024 6:02 AM
*To:* RE-wrenches
*Cc:* Jason Szumlanski
*Subject:* [RE-wrenches] Sol-Ark 15k solar panel frame grounding



Can anybody clarify the following instruction from the manual?



"GND the panel MOUNTS/FRAMES to any GND outside the circuit via 12AWG wire"



Does this mean do not connect the array equipment grounding conductor to
the grounding terminal in the inverter? Where would be the suggested place
to connect the equipment grounding conductor, and why does it make a
difference? It would still be electrically bonded to the grounding terminal
in the inverter.



I'm asking because I do, in fact, have an equipment grounding conductor
from the array connected to the ground terminal in the inverter at a home.
I am getting an F08 GFDI fault. The manual doesn't say anything about the
DC side with respect to this error. It suggests it is an AC current leakage
to ground. But Sol-Ark tech support suggested that I disconnect the PV to
rule it out as a source of the fault.







Jason Szumlanski

Florida Solar Design Group
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