Classic Display Beeps and Shows "GND Fault" Intermittently

[Solar trucker]

 Hi all, it's been awhile since I've written in with an issue...although I've been very faithfully reading the posts here all along soaking up all the info like a sponge!

Ok here's a problem I just encountered.  I have a Classic 150 and a "Kid" mounted on a 3/4" thick piece
of plywood.  One half of the plywood had already been painted white. The part that the kid was on.
Two days ago I shut the breakers for (4) of the PV inputs to the classic and the quick disconnect that
supplies my battery bank, In effect isolating the classic!  THE GRAPHIC display panel went dark as usual
when killing all power to the Classic!
I removed the classic from the board and all associated wiring and sat everything down gently, on a bench very close to the board.  I DID NOT HAVE TO DISCONNECT ANY WIRING WHATSOEVER including the Main Ground.

During all of this, the "kid" was and still is functioning great with one (327W) panel feeding it.

I painted the rest of my mounting board right where it was mounted, let it dry for two days and then this morning re-attached the "Classic" and all wiring runs back in the exact mounting holes.

Proceeded to re-energize all breakers and close main disconnect to the bank.  All Blinky lights went through the sequence and then my graphics display which is remotely mounted 50 ft away shows
"GND FAULT".  SHUT everything down again. Re-checked all wiring including ground for good tight connections and then fired it up again.  Error came up again. So I shut everything down and left it
off for about 1 hour.  Went back and fired everything back up and this time everything seemed to work
fine...for quite a few minutes without a problem...till I pushed the status button on the display and then
it went into GRD FAULT Msg again!   What Gives??   Could there be a communications error between the
Classic and the panel?

[ClassicCrazy]

Why don't you try unenable the ground fault on the Classic and see if everything runs okay . Then turn it back on again in day or so and see if it goes off again. There is menu somewhere on MNGP to do that - but I use Local Status app to change things - easier. It is on the Config / Tech screen where you uncheck a box .

Larry

[Solar trucker]

Thanks for the advice Larry... 

Today I went back and re-torqued all possible connections. Re-energized the classic and everything worked fine for about 15 minutes!  I pushed the status button on the MNGPanel display which is remotely mounted in the kitchen about 30 ft away and it starting beeping again and showing the error msg "GND FAULT"...

I will try your suggestion next...

[ClassicCrazy]

Weird , well maybe you should try putting in the short factory supplied cable that came with the remote just to rule anything out with that though sounds unlikely that would cause it.

I was just thinking that you could try shutting off the PV breaker and let the Classic start up and run and see if it is okay. Then turn on PV and see if you get ground fault. Do the same with the inverter or any other circuits - except of course the battery circuit other wise the Classic won't turn on at all .

Also go to main forum page and do a search for ground fault problem - there are lots of discussions of the past that may give you some clues.

Is the Kid and Classic on the same battery ? Maybe you need to isolate the Kid and if that is causing it then start checking it's system.

Larry

[Solar trucker]

Hey Larry, good ideas...When I energize the classic with just the battery side the display lights up fine and no error msg's or and fault situation...Only when I apply the PV does it go into the fault....I'm going to try to shut off the kid and see what happens!  Both the kid and the classic feed the same battery banks...

[ClassicCrazy]

Nice job on using that roof top space .
But have to do some strategic parking to make sure you get it south  . Beautiful photo .

Larry

[ClassicCrazy]

Do you have the PV and Battery negative on the Kid separated ? No common bond on them ? Just trying to figure out what could cause your ground fault.
How do you ground your system - to the RV frame ?
Larry

[WizBandit]

You have the Classic installed in an RV, the frame is the ground and there is suppose to be current flowing there, some of it is making a detour through the Classic.  GFPD will not function in a vehicle. Remove the GFP jumper inside the Classic and turn it off in the TWEAKS menu.

[Solar trucker]

First of all...thanks Larry, I had to be quite creative when installing those panels...I only have a finite
amount of real estate available and needed to maximize my total watts!  It would not have been possible
to install 1.7 kw up there using 12 volt panels...but with those big babies I'm able to harvest considerable
juice...

The PV grounds and the charge controller grounds are separate, but its a moot point with an RV as WizBandit says...in an RV frame is a COMMON ground and has current flowing there!
Thanks for chiming in with a reply WiZ...what I don't understand is this system has been running now
installed exactly this way with no burps whatsoever...for over 2 years now!  All of a sudden I get this
anomaly when I haven't even removed or changed one wire, or component??

I'm scratching my head?  I guess I could go back right to the roof where it all begins and unhook all
connections and re-connect everything right down to the combiner, charge controllers, and finally the
battery connections... Although your suggestion of removing the GFP jumper and going into the tweaks menu might be the only alternative...The question begs though, why didn't I have to do that 2 years ago?

Thanks all for your constructive comments!

[TomW]

Although your suggestion of removing the GFP jumper and going into the tweaks menu might be the only alternative...The question begs though, why didn't I have to do that 2 years ago?

I bet that you have a worn spot of insulation that is letting a bit of current flow to  the chassis?

That would explain why "now" and not before.

Just speculation but vehicles move and that can cause chaffing or cracking  of aging insulation, etc.

Tom

[Solar trucker]

Tom...you might be right..As I said in my previous reply, it looks like I may have to go back and inspect all the wiring from the panels down to the battery bank..Think I'll start from the charge controllers mounting board, which actually started the whole issue! I'm going to dismantle all wiring to the classic and see what I can find.

[Westbranch]

There is a hand held meter that is used to detect 'leakage ' from battery cells, but I can not remember it's name right now... maybe someone else knows...

[Solar trucker]

Well I guess today is my lucky day!   I started at my charge controller mounting board and almost immediately I noticed
that the positive 4 gauge feed coming out of the classic looked a bit strange.  The reason I hadn't really seen it earlier was
the fact the Lug connector and a good 1-1/2 of wire is covered with wire heat shrink to keep the crimped in the Lug dry from
contaminants...I just yanked on the Lug and it easily came off the end of the wire!

I re-crimped the joint with a new connector and put it back in service...all the while I was doing this task, I had a look on my
face like the cat that just swallowed the Canary!  I was 99.999% that this was my Gnd fault issue...I re-energized the system
and Voila! everything was working fine as it had done in the past...

Thanks to all who replied with your helpful comments...

[ClassicCrazy]

Get one of these and your crimps will never be loose again
http://www.harborfreight.com/hydraulic-wire-crimping-tool-66150.html

[Solar trucker]

Hey Larry......thanks for the link to that hydraulic Crimper...I watched the video and it does look pretty awesome!
Too bad the largest gauge it will do is 0/0...but I definitely will pick one up, actually tomorrow here in yuma as
it will be very handy for all the 8, 10, and 12 gauge stuff I want to do from time to time...