My setup is that I run ESS and charge overnight, then run on battery during the day. Its set to use the internal current sensor and all loads are on AC out1. AC in is connected to grid side.
I’m aware of the overload feature of the MPII - I have tested it with the MPII in island mode and it works as expected (loads are powered beyond the nominal output, overload LED blinks etc). When grid connected however it does not perform overloading. Is that expected behavior? My thought is that it likely is since AC in and AC out1/2 are all connected when backed by an active grid and its to prevent potentially a brief large backfeed as loads stop? Just wanted to confirm as i’ve searched the internet and manual but couldn’t find somewhere that stated this is the behavior of the overload feature
Read the user manual.
It clearly describes all the functions and currents in different modes:
Pass-thru (transfer switch), Inverter mode
Also the capabilities of the assistants: PowerControl & PowerAssist, Dynamic corrent limiter, ESS & etc.
Can also cause grid rejection, depends on the load and the set up.
Technically though if grid is supporting the load there won’t be a problem. You will still still see overload warnings though.
I am wondering though why you haven’t tested that for yourself, you have tested inverting?
What did you experience?
He doesn’t even understand how it works and what is a powerassist. That’s why I didn’t even explain and didn’t give a link to the description of assistants and configuration. Otherwise there will be trouble.
With mains on, the grid is supporting excess load as you would expect - so for instance on the 5kVa MP2, I have with my types of loads/PF, it’ll output around 4.6-4.8kW. Anything above that gets correctly supplemented by the grid. The inverter never enters overload, so i can be using say 4.6kW from battery and a further 2kW from grid. When inverting only it is able to overload, I can use 5.4kW and the overload LED blinks as you expect.
I don’t know if Diessel quite understood what I meant. I was querying why you cannot get inverter overloading (NOT grid/generator overloading) with Power Assist since my scenario is that it’s always grid connected and during specific times I want to consume every bit possible from the battery/inverter before getting grid supplement (without having the inverter shutdown). Hence my query about overload as it would be slightly more beneficial for me during rare intermittent and brief loads to utilize the 130%/30minute inverter overload rather than pull it from grid. While my batteries and cabling have been sized to cope with 9kW for 2 minutes, this is not as useful for me.
The system is setup and working as specified by the nominal figures in the manuals, however none of the manuals have figures for or talk about inverter overload (besides a peak output number with no time/condition parameters and from a fault/alarms POV). I can understand why as its not really a feature, its to save you if you mismanage your loads while off grid for a short period.
So simply the question is - is inverter overloading only available while on “Inverting” and not “Power Assist”? If thats the case then maybe I can play around with the cerbo gx and node red if its able to control the relay that separates AC in and AC out 1/2
I understood you from a half-word. That’s why I gave you the links. With your actions 130% / 30 min. is conducive to the early death of your inverter. Good luck with your experiments. Anything above 4 kW is only for short-term reactive loads measured in seconds.
If you have the ESS assistant running (power assist will/should be unchecked) as the ESS assistant (decides how to power assist) then shifts the grid set point based on solar load etc as you have already seen. (This is up to the max input current limit set on the system, so you can force overload conditions still in an ESS system.)
The max the inverter can add to the incoming is its own ability to invert. So input current (or transfer) and invert shown in the datasheet.
That was all linked in datsheets etc that @Diessel linked.
The answer is there is no real solid answer as it is based on specific installation conditions. There is some expected figures for (inverting) temperature in the inverter datasheet though. The transfer figures are there too.
No offence Diessel but you should go learn more before giving incorrect advice. The 48/5000 is capable of greater than 4kW in normal operating conditions without inverter overload. You’ve highlighted the wrong stat and have totally ignored PF. It outputs 5kVA at 25c as shown in the table. I’d suggest you go learn more about electrics and the relationship between real and apparent power before stating false claims that “Anything above 4 kW is only for short-term”.
Also this video here from Victron disagrees with your statement of anything above 4kW (which is already wrong since its 5kVA) can only be used for a matter of seconds. As long as the inverter doesn’t overheat it is capable of 30% more power than 5kVA for 30 minutes. Which would imply 6.5kVA or roughly 6kW for my loads. I don’t disagree that its likely not good in the long run to use an inverter on overload for extended periods but its a mechanism provided by Victron and I was querying the reason why its only available for me when on inverter only and not while mains connected.
Thanks LX for your inputs, the overload details posted above are not present in any manuals or design manuals (assumed correct as I have not got as far to test the boundaries of the overload besides running my 48/5000 for about 10 seconds at about 5.53kVA).
I’m not after an answer as to what my max boundaries are for my setup/temps. I was rather just querying behavior of the inverter overload (as specified in that Victron video above) and why its only available while on inverter only and not while mains connected. Given no one seems to know and its a “it is what it is” I’ll just be content as to not knowing either..
For all inverters i have ever installed this is found on the datasheet for the product.
Very simply because the inverter isn’t carrying the whole load, so it isn’t an overload.
For Victron kit the product page will have all the datsheets and related manuals. As an example MP2 inverters Datasheet for the MP2 230v version (where Diessel got the information)
There are also tech specs in the relevant manuals, the peak power is mentioned.
It categorically does not contain this information. The datasheet does not have any information relating to 30% overload or the time and temperature conditions in which it can operate, nor does it quantify how peak power works, how long it can last for, or the conditions.
I know its not overloading, i said as much in the very first post. I’m asking why the behavior is like that. If the inverter can overload within design parameters that are assumed somewhat safe since they are controlled by Victron, then why is it not allowed to overload when grid connected. Or at least given an option to decide if you want that. Is it some limitation with grid compliance, country specific rules, other technical limitation, missing feature? This is simply not covered in the literature why its available in only certain operational modes of the inverter.
That is the function of ESS assistant. It allows peak shaving or power assist if using older terms.
30% overload is variable as there is temperature derating and installation conditions such as battery voltage and input voltage from grid.
The system will overload earlier on lowwr grid voltage. Or higher operating temperatures. Or with lower vattery voltage.
Assuming the 5kVa you have installed is not connected to grid, is operating in 25°C (ambient around system components so power in room temp) and your battery has decent stable voltage, you can sustain 4000w x 30% for a while (30mminutes) But while it is doing this it will be heating up and derating. And will most likely shut off with a temperature warning as well.
This now is found in the ESS manuals.
ESS settings and system optimization can force the condition. For example set the input current limit down under the load, this forces the inverter to power assist more - peak shaving- (so invert to loads- peak power for a few seconds) this is making the assumption of course that there is no solar also assisting.
You can set peak shaving to only work above min soc only or always etc.
Two people are telling you the same thing, but you don’t hear it. There are rules for designing systems: Consumption Power + 20-25% reserve = NOMINAL equipment power.(Not maximum, because there is also a temperature factor.)
Then the system will work stably for many years.
If you want more, your next step is the 8-10-15kVA model.
You want the Maximum permitted equipment power + 30% overload.
Good luck, There is nothing more to add.
Diessel, you haven’t added anything meaningful to the conversation since the start.. I have never stated i want to run it in overload constantly. It is a possibility for shorter periods which is why the function exists and i was querying its availability in certain inverter modes.
Yes I have a Cerbo GX, I have node red on it doing a bunch of flows to control/calculate various functions for highest efficiency charging etc, but there’s probably little point continuing this thread as there will be no action point to take. I am perfectly happy to continue letting the inverter passthrough the 99th percentile cases where i might go over my inverter nominal capacity and never have it overload. It just started off that I noticed different behavior in the inverter modes and wondered why and if it could be changed. In any case, thank you for your responses, time and commitment to my question.
Overload is not a mode to run in. No settings no configuration. It is warning you that something bad is going to happen. If you are on mains you should pop a breaker. If you are running on the inverter without Power assist at some point it should shut down
