3x Fronius Tauro Eco solar PV inverters, AC coupled, PV Inverter Support Assistant, on AC Out 1, along with all site loads.
3x Victron Smart Solar MPPT charge controllers, DC coupled
24x BYD BatteryBox Batteries.
Generator on AC In 1.
When running off Victron/Solar/Batteries, everything works perfectly.
I have a manual changeover switch which powers the site from generator only, bypassing Victron units, everything works perfectly.
However, when I start the generator, the generator starts up, but outputs 0v, and then cuts out with an error message. Additionally, if I start up the generator with AC-In circuit breakers turned OFF, the generator outputs 230v. When I flicked the circuit breakers on, it blew up an inverter!
I have checked all my cabling, phase sequences and I can’t find anything wrong.
Has anyone seen this, or does anyone know what would cause this to happen?
At no point in the system is the neutral switched. The generator control panel shows 230v when started with the AC In circuit breakers off, but also verified with a multimeter on the generator outputs and the main incomer which the AC in circuit breakers are on.
From what I understand the Victron has a neutral earth bond, which it opens on detection of voltage on AC-1 in? The generator is labelled as having a neutral Earth bond, but could it be that in reality it doesn’t?
The neutral earth bond opens on accepting the incoming not at detection.
So the incoming breaker only switches line? Sorry just confirming.
Does the inverter have 380 between line?
Are you earthed at the generator or the main consumer? What are the regs where you are?
Are those Quattro’s somehow feeding power back in to the generator ?
Generators don’t like that.
When starting the generator, the relays on the AC IN of the Quattro’s should be open, so for the generator it would seem there’s zero load connected.
Either the relays are closed and the Quattro’s are feeding power back into the generator, or there’s a serious wiring fault.
Star vs Delta ?
Victron doesn’t support Delta.
I will go and verify that there is no voltage on AC in 1 under normal battery operation. Is there a software setting that could cause relays to always be closed?
Normally the AC In relays should never be closed when there’s no AC source active on them.
Could be that one of them is broken closed.
Or a wiring issue (since you have a lot of Quattro’s).
Check the Quattro configuration with VE Configure, ‘Grid’ section.
If you’re never connecting to a grid, it should say “None. Feeding energy from DC to grid not allowed.”
LOM detection is important to make aure the relays are open when there is no incoming power.
Am assuming ess is not programmed as it is offgrid?
If a parrallel set up is not right you can get relays that remain closed as voltage/current passing over them keeps them latched. Still points to a wiring issue.
Can also feedback to/overload another unit and kill it.
Its a big system plenty to go wrong.
ESS is not programmed, the only assistant I have is PV inverter support.
I’m at site now and have verified there is no voltage on any of the Quattros on AC in when just running off batteries.
Don’t know if this makes a difference but on L2 and L3 generator will output 3-6v, and I can measure this on AC 1 terminals.
I’ve traced all cables again and can’t find any phases crossed over etc. Site runs perfectly on either Victron only or generator only, it’s just when the generator runs alongside the Victron!
Maybe I just need to pull everything out and start again
What you could do it maybe just have a three phase, zero parrallel and test generator acceptance. Then re add the inverters in parrallel?
Rather than pull it all out
What is the error on the generator? Overload?
Does the cable megger ok?
The error on the generator is just fail to start, which I think is just because it’s outputting 0v so thinks it has failed to start, as It does actually start, but then cuts out.
Yeah that’s a good idea, I’ll reconfigure with just three inverters and see what happens, hopefully I can find a scenario where it works and then re add each block of inverters until I find a fault.
Thanks so much for your time and help! I appreciate it!
Yes, but on connect the power assist may not be working?
The inverter load plus the ac out load may be higher than the ac out load.
Obviously i amnot there. So shots in the dark here.
By inverter load do you mean for example charging the batteries?
Thing is the Ekrano GX doesn’t register anything on AC In, which I’m assuming means it hasn’t accepted the generator power, and also that the generator wouldn’t see any load? And it doesn’t output 230v and then drop to 0v when the Victron accepts, it just only outputs 0v.
Just thought I’d provide an update! I’ve reconfigured the system to only 9 inverters, and it all seems to be working fine. Generator outputs 230v, Victron accepts and charges the batteries.
When I add in the other 3 inverters, the generator outputs 0v. I’ve tested all cabling and that is all fine so I’m thinking one of those inverters is faulty.
Ah. That is interesting. (And alot of work)
You will have to test them individually before return. Pre RMA test instructions
And thank you for the update
Good to see that you got at least 9 out of 12 working !
And yes, something must be off with (one of) the remaining 3 Quattro’s.
You could try to configure those three as standalone, feed one of them with a single phase and check if it accepts the power or blows a fuse, then test the next etc.
The fact that your generator outputs 0V makes me suspect some kind of short circuit between neutral / phase / ground or a ground fault inside one of the Quattro’s.
