System, Quattro 10kw, 120 vdc, MPPT 250/70 x 3 each, Cerbo and color scren, smart shunt, 12 each Battleborn 24volt cabled for 48vdc 10kw sunpower arrays. Honda 3000is
So for a few days now my system has shut down overnight low voltage. Which surprised me as the shunt would read in excess of 49vdc. AS I am new to Victron I gave been tinkering with settings on the Quattro and shunt as per suggestions here and Battle Born. Yesterday the Quattro would not accept generator until pv had built the system back up to above 50 vdc. then accepted and charged. Why would the Victron inverter not recognize the generator when it is most needed?
Today on suspicion that my bank of batts might be imbalanced I am running the genny trying to build to full power in concert with the arrays, since I want to do a full test per BB process to see if some variance exists there. But the Quattro will periodically disconnect the genny then reconnect. This phenom has repeated all morning. I find no clue in the manual, but do not deny it may be there and misunderstood by me.
If the Quattro disconnects, then the input was out of spec. Voltage too low or high, frequency too low or high. Also the i in 3000i is an indicator for an inverter generator, its essentially a DC generator that feeds an inverter internally. By hooking it up as a source for the Quattro you are creating an inverter cascade, which is discouraged by Victron.
Are there any load variations when this happens? Have you played with power assist current boost factor? Since the generator is noteably smaller than the Quattro, maybe the standard 2.0 factor is a bit high.
Have you set a grid code in the Quattro? If yes then you could look at the NS log to figure out why exactly it switches the input off.
Thank you so much. Your comments are quite interesting. I am off grid so never set a country code. Should I?
I have noticed prior to disconnect that the quattro suddenly draws the genney down, with no apparent change in load. As I am outdoors most of the day and that equipment is not, I have not seen real time behavior. Should work out a way to do that. But I guess the sudden draw down could cause the out of spec issue. Not sure why that happens though. I am not sure what “an inverter cascade” means but does not sound good. I migrated to Victron from Outback which had no issues with almost any generator, I even had a pto generator back in the day. So this particular fussiness is new to me. ( Outback had plenty of other issues though)
I will set up the laptop and look for the power assist factor. I had set the ac input at 20 amps trying to prevent overload of the little back up generator.
Of course I do not understand why the Quattro would not connect to the generator until the sun came up enough that it was no longer showing low voltage. Seems an odd behavior to prevent use of the generator when most needed.
Do note that when the Gen is running, it has to charge the batteries and supply the load - this includes load surges when e.g. a refrigerator starts.
For this reason, particularly with a small gen, you need to set the charge to less than 50% of the rating.
Also with inverter generators, these tend to throttle back the engine until it is only supplying sufficient power to meet the load (eco mode) This means that there is no reserve momentum to meet a sudden demand surge. This is why these are not recommended as charging sources.
As mentioned above, there should be a log on the grid page, I find this as the PE log - even without setting a grid standard, it should give you the reason for disconnect - usually low voltage or frequency. Poor harmonic content - wave shape should not be an issue with an inverter generator, unless there is inadequate power from the motor.
I would say this is correct, but every country is different in its electrical standards, so im not sure. However, setting a grid code will make the voltage and frequency window narrower, so by having no grid code set you got the biggest margin for voltage and frequency deviations.
The thing with inverter-generators is, that theres no connection anymore between engine rpm and generator frequency. The engine and the DC generator do the same thing as your 48V-battery does, supplying energy, which is then passed through an inverter to make AC voltage, like the Quattro does. If the load is low enough, the engine will run at low rpms. So its possible that the engine rpms going down is due to the load being lowered. This could be caused by the power assist boost factor, or the Quattro already disconnected at that point in time, but of course can have other causes as well.
Its essentially one inverter feeding into another, so one electronically generated sine wave feeding another electronic inverter/charger. It can work, but its not officially supported
Thats interesting, ive never saw one myself when no grid code is set, but maybe the log is not part of a remote config file
You folks are great! So thankful that my betters ( electronically at least) will take the time to help. Been a long day so will take this issue up again when the sun rises again. When I am trying to build battery and help with loads I never use eco mode. It simply is not quick enough for sudden loads like a 3/4 hp pump etc. So there is no issue with the Honda needing to accelerate.
Other than setting the Quattro to only demand 20 amps, and turning on the power assist I am not sure what to do besides buy a bigger generator. That’s probably not an option as I am selling my place and moving out of the USA. Just do not want a buyer to have troubles.
Also I have the Quattro set at default to allow generator on at 37 volts, but it would not connect till the sun had the batts up to 51 vdc, then connected and stayed. Wonder what setting I have missed.