Hello,
I have a SolarEdge (SE) SE3500, AC coupled to my Victron MP2 8kva. The MP2 does a great job of throttling the frequency to control the SE, works a treat in winter, but is now cutting out and overloading, now the sun is shining more, here in Dorset?
Things I have learnt and done, from this community, that have improved this situation, include:- Fitting a 6mm sq cable from the AC out 1, to a “Critical Load Consumer” unit, which is running the kitchen ring main and the mentioned SE. Put ‘B’ type RCBO’s on the victron and the Solaredge. Switched on the Alternative Power Source on the Solaredge and set the matching frequency on the MP2 and SE (PO=50.2 and P1=52.1). Lowered the MP2 voltage to the SE to 230v supply.
If I switch it over to charge the batteries, by the mains, it charges to 100%. (constant supply). However during the day, with solar charging, anything above 1700w and the MP2 raises the frequency and turns off the SE, even if the battery is only 75% charged.
I do prefer to charge the batteries slowly, so I turn on a 1000w blower heater, which allows the batteries to charge slowly up to 95%, to switch on the AC out 2 relay to heat the water tank. So the heater smooths out the fluctuations from the solar, and stops the frequency raising, cutting off the SE. Any advice would be welcome, to stop the SE cutting out? Many Thanks Limpet.
Hard to say based on the information provided. A few things come to mind:
What kind of batteries do you use? What kind of BMS? Is DVCC active? Anything limiting the charge current?
Is SolarEdge on ACout? Is grid present in situations in which SolarEdge is throttled?
Btw: P1=51.2, right?
Your questions are very valid, having read the community rules, I was trying to keep it simple with one question.
The batteries are self build, copied from Andy of the Off grid Garage, 12kW using JKBMS. Been in full use for 2.5 years.
DVCC is on, Limit charge current is on, Max charge current 50A, Limit Battery charge voltage is on, Max battery charge voltage 55.4v.
The Solaredge is connected to AC out 1, via ‘B’ type 20amp RCBO, in the critical load consumer unit.
No grid is present.
You are correct with your question. P1 according to the “Intergrating with SE” should be 51.2. However someone on here got out of a similar problem “Sunspec” problem, by increasing the tolerance. So I was trying 52.1. As they did.
The Solaredge frequency, supplied by the MP2 ticks over happily on 49.9 to 50.1 most of the day. But a sudden blip of sun or turning on/off the Immersion, it jumps up and switches off the SE. Unless I have the 1000w heater running.
I would like to slow/regulate the charge current. As it does not feel right to me when it pushes 2kW into the batteries.
Thank you for your thoughts.
Limpet
I’m not familiar with JKBMS so I can’t comment on this.
Did you track the charge current to see if there’s a correlation between the current and the increase in frequency? This shlould be possible using the advanced section of the VRM.
If your goal is to charge with lower current, you could also try to limit production on the SolarEdge side. This might help to stabilize the frequency.
Hi UHae,
Thank you for your reply.
I saw the original demonstations for the Mk1 JKBMS, by Andy (off grid garage) on utube, 3 years ago. I was very impressed, even more impressed when I got two of them.
I think they are onto the Mk3 now, certainly worth a look at one of Andy’s video’s.
Thank you for the suggestion of “Tracking the charge current”. Not something I have done before, please can you give me clue as to where to find it?
Which section of the SolarEdge, would I be able to lower the current limit? As it may just solve the problem.
Many Thanks
Limpet
You should be able to see the charge current in the advanced tab of the VRM. You can visualize charge current and frequency to spot anomalies.
Limiting the output of the Solaredge can be done by using the SetApp and connecting to the WiFi of the SE inverter. Although I haven‘t done this before as I control my SE via an integration in Home Assistant.