Conext 6848 died tonight.

WaterWheel · December 2023

Ok, Looks like my 6848 may have developed a problem and I'm looking for suggestions as to where to start troubleshooting. Please understand that I work from sunup to sundown during the week so it will probably be this weekend before I can really open things up.

Wife gets home this evening and the Christmas tree in the front yard is lit up. Garage door opens normally but only after it refused to close before she realized the house power had gone out.
Inverter is grid tied and after a sunny winter day Conext battery monitor shows 99% charge. Controllers show normal charging.
Inverter is a bit over 8 years old and we suffered a serious lightning strike about 15 months ago. Dave warned me on this forum that I may have problems from the lightning strike in the future. Here is the discussion on that topic. ttps://forum.solar-electric.com/discussion/357487/lightning-strike-blew-battery-caps-off#latest

I got home 20 minutes later. Power had obviously just gone out. The Conext SPC display was powered up and the most recent fault registered 6 hours earlier as F39 which is " Under voltage anti-islanding fault, caught by the qualifying limit between L1 and L2" In our rural area this is a code we see roughly once a month.
Grid power was still on to the house but the inverter had not switched to grid power so I flipped the switch to "Grid Only" in the Conext PDP breaker box and the house power comes back on. I disconnected the inverter using the 48v breaker in the PDP for a few minutes before switching the battery power back on for the inverter. SPC is not showing grid power when grid is on. Grid power is obviously on but the inverter is not seeing it.

The SPC shows that the inverter is "qualifying" the grid power but the inverter never kicks on showing the 300 second countdown as it would normally do.

Suggestions?

Dave Angelini · December 2023

Ouch ! Some facts on the usual high reliability of XW. Many, and I mean many seem to last forever in an Offgrid application that does not use a generator.

The Offgrid failures are very low when the generator is a large reliable bolted down, quality genset.

For grid use there just are so many ways that a surge can get into your power system. I think you have SPD's everywhere right? You have the old lightning strike hit SPD's tested by Midnite or replaced? Just because the blue LED is on after a near strike is not a guarantee.

I would try the DC disco again and this time measure 0 vdc on the XW battery terminals. Let it sit this way for 30 minutes.

That is about all of my general advice. I would take a look on Insight Cloud. Maybe someone else can chime in. Good luck!

WaterWheel · December 2023

Dave, I never sent the SPD in I suspect was the one that the lightning came in on but I had a spare DC SPD and replaced the old one. In total I run 3 DC SPDs on two panel sets and 2 SPDs on the AC side.

While I've shut off the battery breaker to the inverter for 24 hours and after powering the inverter back up it still was not seeing the grid. Nor will the inverter power anything with the grid shut down. When powered back up the 300 second countdown starts and you can hear the transformer? buzz for a bit.

But, I've noticed that the battery monitor stays powered up with the breaker off because the battery meter powers directly off of the battery bank. Perhaps enough power is running through the Xanbus system to keep the inverter from fully discharging.

I'll unhook everything from the battery and see if that helps.

Update... battery bank fully disconnected for 30 minutes with same results. I will have to wait before I can try to disconnect AC and battery bank. Disconnecting everything on a cold night would be bad for my health according to my wife.

P.S. I've never hooked a generator to this system.

WaterWheel · December 2023

I finally got to open up the inverter between Christmas cleaning chores. I could find nothing that looked like it had burned although I did find one loose wire from my smaller panel array where the power from the panels goes into the breaker in the PDP. I did find a few whisps of spider web which I gently cleaned out. Most of the web was in the PDP (breaker box) with very little web in the inverter.

Using the SCP (monitor display) for most of the information in this paragraph. Powered things up and the inverter works providing roughly 90% of the power for my grid tied home. But when I shut down the grid the inverter would shut down. Tried this several times. Normally the inverter instantly takes up the load when the grid is off. When I swap to grid only power in the PDP breaker box using breakers normally the change is instant as I flip the breakers. But even though I'm using breakers to change the power over it takes about 5 seconds before the now grid powered lights to come back on. Weird because is a mechanical switchover with the inverter not part of the process. Did that test twice with the same 5 second delay before the grid started to power my home.

So I go back to the SCP (system controller mounted inside the house and scroll through the menu to find that it shows the inverter is disabled. There is no way I had disabled the inverter.
Rember that this all started when my wife open the electric garage door but when she tried to shut the door the power went out. I wasn't even home at the time.

Anyway things seem to be working normally now with the inverter now "enabled" and the XW inverter after 8 years is still faithfully providing 90% of the power to my home.

Conext 6848 died tonight.

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