Stacking Error on GVFX3648. Master Unit Dead.

Discussion about OutBack Inverters in Grid Tie Applications

Moderators: OutBack, OutBack Moderator Team

Post Reply
Dan E
Forum Member
Posts: 23
Joined: Tue Jul 03, 2018 8:16 am
My RE system: 2-GVFX3648
2-Flexmax 80

Stacking Error on GVFX3648. Master Unit Dead.

Post by Dan E »

I have a 7kw FLEXPower TWO FXR system with two GVFX3648 Inverters, two FlexMax 80's, and battery backup. It is about 9 years old. Last week we lost power in the house. The Error msgs were: "Stacking Error Detected," and "Low AC Output". The Master inverter (P01) was dead.

I did a factory reset on the inverters, the Slave (P02 ) switched to "Master", and that unit shows no errors or warnings. However, when I switched on the AC, the lights in the house began to cycle off and on. I immediately shut it down.

I contacted Outback support, and they said I needed at least a new control board on P01, and maybe more. They also mentioned a possible firmware incompatibility with the P02 unit. I am in no position to return the units for repair, but I am able to replace the boards with help from a friend.

Has anyone experienced this problem? Any suggestions?

Thanks,
Dan
raysun
Forum Emperor
Posts: 5286
Joined: Tue Jul 26, 2016 5:57 am
My RE system: Flexpower Two: (2) FXR3048A-01, (2) FM80, MATE3s, FlexNetDC
SimpliPhi 48-3.8 (6 @ 48v)
Outback IBR3 battery enclosure
REC Alpha 440W panels - 2 arrays: each of 4 strings of 2 in series
Honda EU7000is gas fuel generator

Re: Stacking Error on GVFX3648. Master Unit Dead.

Post by raysun »

I haven't run into board failures on the old FX (VFX, GVFX) series inverters, but lots of folks say the boards are fairly easy to replace. The trick with stacked units is to make sure the firmware versions are compatible, which generally means the same "dot" release.

The other issue is "board swap bingo". Its hard to diagnose failures in the field, and often multiple parts are swapped before the issue is cleared, if at all. Not a terrible approach for a service center with lots of boards on hand. Not so good for an end user who has to buy them on a non-returnable basis.

The older boards are more readily available from 3rd party vendors rather than directly from Outback, generally cheaper too.

Arizona Wind and Sun, and these folks: https://www.zonnaenergy.com/solar/repla ... vfx-series have been mentioned in other posts as sources.

FWIW, in the past 9 years, OB has made great strides with the FXR series. More full-featured than the FX class. The old units (in working condition) have decent resale value. An upgrade is more expensive, certainly, but may be worth considering.
Dan E
Forum Member
Posts: 23
Joined: Tue Jul 03, 2018 8:16 am
My RE system: 2-GVFX3648
2-Flexmax 80

Re: Stacking Error on GVFX3648. Master Unit Dead.

Post by Dan E »

Thanks for the info. I am still debating my next step -- trying to weigh the pros and cons.

I noticed there was no part number on the Control board, but it did have this number on a white sticker:

001.100.000

Is that the firmware version?

Thanks,
Dan
raysun
Forum Emperor
Posts: 5286
Joined: Tue Jul 26, 2016 5:57 am
My RE system: Flexpower Two: (2) FXR3048A-01, (2) FM80, MATE3s, FlexNetDC
SimpliPhi 48-3.8 (6 @ 48v)
Outback IBR3 battery enclosure
REC Alpha 440W panels - 2 arrays: each of 4 strings of 2 in series
Honda EU7000is gas fuel generator

Re: Stacking Error on GVFX3648. Master Unit Dead.

Post by raysun »

Dan E wrote: Tue Jun 15, 2021 8:42 pm Thanks for the info. I am still debating my next step -- trying to weigh the pros and cons.

I noticed there was no part number on the Control board, but it did have this number on a white sticker:

001.100.000

Is that the firmware version?

Thanks,
Dan
Sounds like a firmware version.
Dan E
Forum Member
Posts: 23
Joined: Tue Jul 03, 2018 8:16 am
My RE system: 2-GVFX3648
2-Flexmax 80

Re: Stacking Error on GVFX3648. Master Unit Dead.

Post by Dan E »

Thanks,
Dan
Dan E
Forum Member
Posts: 23
Joined: Tue Jul 03, 2018 8:16 am
My RE system: 2-GVFX3648
2-Flexmax 80

Re: Stacking Error on GVFX3648. Master Unit Dead.

Post by Dan E »

raysun wrote: Tue Jun 15, 2021 6:46 pm I haven't run into board failures on the old FX (VFX, GVFX) series inverters, but lots of folks say the boards are fairly easy to replace. The trick with stacked units is to make sure the firmware versions are compatible, which generally means the same "dot" release.

The other issue is "board swap bingo". Its hard to diagnose failures in the field, and often multiple parts are swapped before the issue is cleared, if at all. Not a terrible approach for a service center with lots of boards on hand. Not so good for an end user who has to buy them on a non-returnable basis.
Update: I believe I misspoke in my original post about firmware incompatibility, based on my misunderstanding of a statement by Outback Tech Support personnel. I now believe the firmware incompatibility was not between the inverters, but among the 3 boards inside the dead converter. I believe I will be able to obtain a new control card with original firmware for the dead unit, so firmware may no longer be an issue. I am still trying to get around "board swap bingo."

Question: do you or anyone else know of a way to determine which board is bad using a multimeter? I visually examined all three boards and could not find any burnt or scorched areas. The inverter is dead, so the Mate doesn't recognize it.

I would have contacted my installer, but he moved his business to Texas years ago.

My 2nd inverter works perfectly, and is delivering power to the house and keeping the batteries charged.

Thanks,
Dan
raysun
Forum Emperor
Posts: 5286
Joined: Tue Jul 26, 2016 5:57 am
My RE system: Flexpower Two: (2) FXR3048A-01, (2) FM80, MATE3s, FlexNetDC
SimpliPhi 48-3.8 (6 @ 48v)
Outback IBR3 battery enclosure
REC Alpha 440W panels - 2 arrays: each of 4 strings of 2 in series
Honda EU7000is gas fuel generator

Re: Stacking Error on GVFX3648. Master Unit Dead.

Post by raysun »

Question: do you or anyone else know of a way to determine which board is bad using a multimeter?
This would only be practical in one of two circumstances:

1) a very detailed circuit diagram was available, noting component voltages and currents under a prescribed test condition. (AFIK, no such service diagram is available to the end-user.)

2) luck. Probing the boards (very carefully, and not recommended) happened to turn up an obviously dead circuit. Most likely, this sort of "reverse engineering" is best carried out by an experienced technician, and the tool of choice is an oscilloscope at minimum.

Bear in mind, exposed boards can carry lethal voltages "blind probing" in such circuits is not generally a good idea.

Were this my conundrum, I would follow tech supports suggestion and start by replacing the control board. I'd assume the guidance stems from the most common solution to the described symptoms.
Dan E
Forum Member
Posts: 23
Joined: Tue Jul 03, 2018 8:16 am
My RE system: 2-GVFX3648
2-Flexmax 80

Re: Stacking Error on GVFX3648. Master Unit Dead.

Post by Dan E »

That is good advice. Thanks.

Dan
Dan E
Forum Member
Posts: 23
Joined: Tue Jul 03, 2018 8:16 am
My RE system: 2-GVFX3648
2-Flexmax 80

Re: Stacking Error on GVFX3648. Master Unit Dead.

Post by Dan E »

Update:

I ordered and received a new control card, and everything seems to be working Ok. Thanks everyone, including Outback support, for your help.

Dan
Post Reply