Folks, I have a system running where the Load balancing or the grid current limit does not work. The situation is as follows:
3xMPII 5k
VM-3P75CT as grid meter (roll → grid meter)
Loads on input and output
The system only looks at what enters the MP via AC in and responds well to that. But if something before AC in comes in, things go wrong. Main fuse tripping as a result.
The setup:
MP’s latest firmware and ESS assistant. VE configure AC input current limit 25A and overruled by remote checked.
On the Cerbo: FW 3.54
Position of AC loads → AC input & output
Grid meter → external meter
Peak shaving → always
Max system import (and output) current → 25A
It looks like the system is acting as it was before OS 3.30 and older MP firmware and assistant. Anyone have any ideas?
Hi LX, I’ve tried to set the limit om 10A as well. The system just doesn’t take the loads in front of the MP’s into account. When I put everything on ACout the peak shaving works flawless.
Yes I did update everything to the latest versions. No beta.
In the mean time I found this posting from @SmartVolt : Grid current limit exceeded with DESS and peakshaving on - #3 by SmartVolt And indeed that seems to work. Only problem is that when you have only loads on ACin configured in system setup, you won’t find the menu self-consumption from battery in ESS. So I went to system setup, said system has loads on both sides, went to ESS → self-consumption from battery, put in on all system loads. Now it works. After I went to system setup and putting it to loads only on ACin the menu item self-comsumption from battery disappeared again but it still works now.
This is a useful remark. What metering are you using? How much of a load?
The problem is for some it is a set up problem. Some are half updating firmware. Or using a mix of beta and old firmware. And there are those ignoring some guidance in the article.
Summary
The GX does not limit PV-inverters in relation to the new export current-limit. To illustrate: in case of major solar production, at the same time as a high-tariff for selling energy to the utility, the new mechanism will limit feed-in power from the battery to zero. So, as long as the installed PV Inverter system is configured in such a way that it can’t by itself blow the fuse – then it’s fine.
Such as this one. So before bug gets tagged some more details are usually needed and troubleshooting steps need to be taken. All of the questions and dialogue help narrow down where the issue may be since each systen if fairly unique @huib is makes sense not to create a very long confusing post. For example are there some loads causing the issue. Is it related to phase balancing. Many factors. Is it on import export or peak shaving? What is the battery state at this time. So your comments are not being ignored they are being explored.
I use VM-3P75CT as grid meter (roll → grid meter). There are 2 3-fase PV inverters metered with a ET340. AC PV can do max 17 kW so it will never exceed 17 kW my 3 x 25A grid connection can handle. I did not test yet what happens when DESS decides to push back full throttle while the PV inverters are doing the same. There is not enough solar at this time of year. So importing is the only thing I can test and that worked out well.
The bug is in way you make the right setting. This is very confusing and should be designed better. Or at least it should be properly described somewhere which it isn’t right now.