I have a Grid-tied UPS setup, using two Quattro 5k’s. It’s worked well for a few months, with occasional outages and recoveries-- very minor ones. Recently, we had our first major outage. The batteries are drained to ~2%, but the inverters aren’t reconnecting to grid!
In the status screens, it shows that it sees AC-In voltages and frequencies that look healthy
I’ve also enabled wide frequency input.
We’ve tried power cycling with the main Quattro switches, resetting the VE.Bus, and I’m at a blank… please help!
We also just noticed the second inverter’s status lights went off and the first unit is flashing status lights between Inverter On and Float–the manual doesn’t have anything listed for this…
We have had roughly weekly outages with no issues before, but never 24 hrs draining the batteries this much
The alarms are making me distrust the VE bus. We’ve tried resetting it a few times, sometimes with differing effects.
I was upset with Signature Solar for not providing cables for these connections, but I seemed to have got it to work in the past… Here’s what I understand about the VE bus:
There are no terminations, like on the VE Can.
We’re using CAT 5E cabling that we had around.
I have one cable from each inverter going into the VE bus ports on the GX. Of the cables I had, one of the cables is Cat 6 patch 24 awg, the other is Cat 5e 26 awg (not patch)
Your primary problem ist lost grid, sometimes victron inverters have problems connecting to generators, due to waveform distortions at high charge currents.
Should be solved with firmware v552, so you might try to upgrade.
The connection on the ve bus is one inverter to the other than then one from the inverter to the GX. (I usually use the master. I don’t think it matters - never tried it anyother way.)
They use straight (also known as patch cables between the gx and the inverters.)
You are correct you don’t need a can terminator.
The system is in float with is strange if it needs a charge.
How is your system programmed?
@lxonline We tried switching the ethernet cables as you described. Sadly no improvement.
Update:
I reconfigured the units to be independent (turned off any 240V split phase loads). The master unit came back to life, is passing grid power to the loads and charging the battery!!
The second unit is faulted, but I can’t figure out in VictronConnect how to read the fault (using the PC version). We also noted the GX display wasn’t displaying the faults earlier… not sure if related.
I’m hoping maybe it wants a higher battery voltage, and it will come to life in a bit with more battery charge. But I’d really like a way to read the fault…
@Ludo Understood… wouldn’t the other inverter fault if this was the issue? The other inverter has been rock solid.
@lxonline Correct, we went in and reprogrammed both inverters to be standalone using Victron Connect. It does show a fault, but we can’t see what it is!
To be clear, we disconnected the second inverter from the Cerbo GX (we tried with it connected to the GX and the other inverter disconnected… no difference–faulted either way)
Checked firmware versions a few days ago—all updated.
The VE Bus tools is something I’ll try to read the faults. (Sadly I’m doing this all remotely, with a friend at the house… can’t try now)
I will also check a few settings to make sure they were mirrored correctly:
Accept wide frequency range
Weak AC
Power assist off
check voltage limits
I could have sworn I checked if the AC ripple was triggered, but will do again
With the units independent, it lets the good unit charge the batteries, while the bad unit inverts to supply power to the loads… works okay for now. I just can’t power my 240v water pump.
@Ludo, where do I find the information on why it’s not connecting? We didn’t see a fault, but this one unit is still on inverter only (the other unit working well).
I verified the following settings: Accept Weak AC: on; Power Assist: off; Accept Wide Frequency Range: on
Voltage and frequency were in-spec, and no errors
Here is the display from VE Configure, looking at the VE Bus. Should UMains be orange?
Second, we noticed the following in the NS Protection Log. I think this refers to the battery… could be related to how we’re messing with the VE Bus connections to get the two Quattros operating independently for diagnosis… This inverter is operating without comms to the GX, battery, or shunts. My quick google seems to indicate these under voltage entries refer to the battery–which is working fine. Let me know if you all have other thoughts.
No, the errors are in the GRID tab, so they refer to the incoming ac voltage.
And ofc the ac-in should not be orange.
Disconnected you have 120v, as soon as the multiplus tries to connect the voltage breaks down. So there must be a loose contact in the wiring or a defective circuit breaker.
For the checked assistant function you’ll have to check the other tabs on this page
Interestingly, when we went to tighten the connections, the grid was down… had a 6+ hr outage before we got feedback on if anything changed. But alas, we still have a fussy unit regarding accepting the grid.
We did take screenshots of all the VE Configure tabs. Again, I don’t understand the Virtual Switch, so I’d love help looking at those settings. Of note, now the frequency is also orange… the values look totally fine to me though! We’re still getting the Under-voltage log entries on the grid tab…
