Quattro "semi" off-grid

My setup is Quattro Victron 48/5000/70-2x100, Cerbo GX, Smart Solar MPPT VE.Can 250/100 rev2. All latest updates.
I have an issue is that i have 2 sources, one is Grid and the other Generator. The limit i have on Grid works great and amazing. When my panels are generating, the input from grid is minimal and the panels are sufficient for output and charging batteries, when the batteries are empty and full. the limit is always as i put it.
When on generator all the system goes crazy, no specific rule is followed. sometimes the limit is respected, though most of the time it is not, it fully takes the load from generator (even when there is enough solar, when the batteries are full, and when not full). and it is not even static, so it takes full load for couple of minutes, then respects the limit then back again.

what i am trying to achieve are the below points:

  1. i want to keep the 2 sources though with a hard limit that i set
  2. in case the soc of the batteries drops below the 50%, i want to whatever source is on to kick in and keep the voltage to 48V
  3. in short i dont want to draw anything from source grid or generator (or at least the bare minimum), as long as i have PV or enough power in batteries.

your assistance is highly appreciated

Hi @vuser
Generators can be problematic because few like having an instant power draw applied, Try enabling Dynamic Current Limiter, like a ‘soft start’. More about other issues here… MultiPlus Generator FAQ [Victron Energy]

Adding logic to your AC switching is a little more involved. I’d usually head straight for Assistants, but this YouTuber may cover it. I haven’t watched it all myself… https://www.youtube.com/watch?v=4ZsGHi8nKGc

You’ll need to think over your “48V” target. Like it’s impractical to run a genset at near idle, so you may need to consider operating over an SOC range with your switching.

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Thank you for your response.

I have seen the link you provided, mainly it focuses on Generator being disconnected. My issue it is taking more than i want from the generator. i want to limit the generator to 1A, but in reality it gives the full load from generator eventhough the load is small and batteries are full.

if i missed the part regarding how to limit generator, can you please specify it.

thanks

The genset should honour the set limit, but first you have to sort out it’s actual acceptance. It may be tripping itself when hit with a full load, and/or the Quattro may be rejecting it when it goes off-spec. In either case that may show as erratic results, especially if you’re watching them on the ‘Generator’ tile on VRM (that tile has some issues). That’s why the soft start.
Your Quattro can’t be set to an Input Limit lower than 3.9 Amps (I looked it up). And I can’t imagine why you’d want to waste fuel with 1 A anyway? Ok for testing I guess, but you can’t set it that low (and firmware earlier than 485 may be even worse).
If you can hear the ACIN relay clicking while you’re seeing this instability, then your first priority is to sort that…
I would set the limit in VEConfigure to be sure, but you can do it in Cerbo normally. If Cerbo says 1A then it won’t stick…

Hi JohnC,

The “Generator”, is not a generator that i own, it is actually a very big generator that gives a lot of people, in our country we dont have Grid 24/7 and thus a generator feeds a small sector.

nevertheless, my issue is not accepting the Generator feed, it is accepting it normally. My issue is that it doesnt honor the limit even for small load like 1-2K. as i mentioned. sometimes it does honor it and sometimes it doesnt.

i am also able to set to 1 A. i can added it manually and limits to that much, not 100% exact, but extremely close.

though with the “Grid”, it honors it extremely hard that even if i am close to overload, it doesnt take extra from Grid.

any clarity on why this is occuring with me? i think if i set the AC2 to “Grid” it will honor it, but my issue there is that i want 2 info for input and when i set AC2 to Grid, it doesnt seperate what i am taking.

To use a 1 A Input Limit you must have Power Assist turned off. I haven’t any experience running without that, but I suspect may be the cause of your woes.

Try enabling it, it’s one of Victron’s best features anyway…

tnx a lot much better with the Power assist. i will be testing that.

though i still can limit to 1A or any number

i have an issue that occurred, not sure if because of the power assist. When the generator stopped, the inverter cut-off the electricity from home, and then started again after few seconds from batteries. i that due to power assist, eventhough generator goes on and off several times a day and it doesnt happen that the inverter goes off… any ideas?

the ups function is off. it was adviced by the installer not to use it same as power assist…

There’s something wrong if you can set the Input Limit to 1A. Maybe a firmware incompatibility thing somewhere? Until you sort that, set it above the published value, say 4A.

With the Power Assist, set the Boost Factor to the default 2.0
You could try it with UPS enabled, then an ACIN rejection is usually seamless changing to batteries. Like a tv set won’t even flicker. But maybe your supply is ‘browning out’ somehow. In that FAQ link I posted there’s some info on how generators perform and how to deal with it.