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current limit

AC Current Limit when using ESS as a grid parallel system

I have a Multiplus II GX system which is installed with the ESS application. It's connected to the UK grid via a single phase 100A supply, connected to AC IN of the Multiplus.

All loads and an AC coupled solar inverter are also connected to AC IN of the Multiplus.

The Multiplus is able to balance the grid supply close to zero, charging the batteries off of solar and discharging them as required. I also have time of use tariff which enables the Multiplus to charge the batteries over night.

The issue I have is that I run a lot of loads over night in the cheap period of my tariff including a 32A electric car charger. This regularly take my load over 50A.

The Multiplus needlessly regulates its own charger down in this period and on occasion supplements my grid supply from batteries. This is needless and results in me not having a full battery bank at the end of the cheap time-of-use period.

I can't increase the current limit beyond 50A on the Multiplus or seem to disable it. It is not needed in a parallel grid connection as I have it, as far as I can see.

Can somebody advise me as to whether I have missed a setting or if this is something Victron need to consider in a future firmware update. I want to be able to heat my water, charge my car, batter bank, run my dish and clothes washers during my off peak period!


Marcus Fosker asked
davebaldwin commented ·

4 Answers

Multiplus/48/3000 connects to Generator but doesn't charge. DVCC or tail current issue?

Hi All,

I'm running an off-grid system using MultiplusII/48/3000 with a Cerebo GX, MPPT/250/100 VE.Can rev2, SmartShunt 500A all connected with VE.Can. My battery setup is 20x 250A 12v Gel batteries in 48v with 3 battery balancers.

On the Multiplus AC input we have a 7.5Kw generator that we've configured to start when GX relay is turned on. We want to use the generator on cloudy days top up the batteries while briefly running our critical load.


When we start the generator and the Multi accepts the input, we see the system taking over 1000W from the gen to supply load and help charge the batteries alongside the MPPT250/100 as we expect. However, after less than 2 minutes, the load on the generator starts to drop in a very controlled fashion. It appears that either Multi or another device is limiting the generator input for charging, even when the MPPT is clearly still in bulk and the batteries need charging. This makes us very nervous about when bad weather will come and we'll be reliant on the generator charging the batteries.


We have not enabled DVCC yet for this install as we're not entirely confident about its impacts with our setup and running these Gel batteries. We also have issues with the Smartshunt's tail current settings not being able to set the % value below 0.5%. Given we're running over 1000Ah storage capacity, a tail current value of 0.5% is still 50A! We'd need either an Amp value or 0.05% to get to a more normal 5-7A tail current setting. I believe this results in our batteries always showing 100% as soon as the MPPT's start charging in the mornings.

We suspect it may be the tail current setting with battery SOC always being at 100%, but we are unsure this is why the Multi is not using the generator for proper sustained charging along with the MPPT. Perhaps because we're not using DVCC and this will help with global control of all the devices working together?

Attached some pictures showing setup and generator on but not charging. When MPPT is on, it give charge to battery. When MPPT is off, generator still doesnt charge.

Gen with MPPT.jpg
Gen without mppt.jpg
Smartshunt settings.jpg
Multiplus settings 2.png
Multiplus settings 3.png
Multiplus settings 4.png
Multiplus settings 5.png
Multiplus settings 6.png
physical setup.jpg

kmr asked
kmr commented ·

1 Answer

Grid feed-in / maximum phase current

Hi

I would like to know, if the grid feed-in setting (watts) is single- or three-phase, when you have three phase grid and only one multiplus in a system? I have a grid meter, Fronius on-grid 3-phase inverter on multi input + Easysolar 2 on phase 1, and together they could blow the phase 1 main fuse if load is low enough and there is enough solar power available. This is for outgoing energy, but the same question applies for consumption:

Is there a way to limit Easysolar/Multiplus charge current via grid meter, to avoid blowing main fuses? (25A main fuse, ATM 16A max grid charging current, but other appliances might be powered while charging and the risk of blowing the mains is real).

I've tried to search the forums and manuals for this info, but haven't found an answer yet, so I would be very thankful for any insight on this matter.

Kari Saaranen asked
Alexandra answered ·

1 Answer

Cannot change Multiplus 24/3000/70-50 Input Current Limit changed in Remote Controls

For the life of me, I can't figure out in VE Connect which value corresponds to changing the input current limit in the remote controls so I can increase this to 70amps on the input current limit.


Help?

[image]

allswell asked
allswell commented ·

2 Answers

Transient current cause Seplos BMS to shutdown

Hi Victron community, I have one question regarding a couple Victron / DIY LFP pack with Seplos BMS.

If it is just to say that Seplos is not in Victron's compatibility list for BMS, you can save your time and are not forced to participate to this thread ;)

I use this BMS (I have 4 of them) and it is working fine, but, as there is a "but", a big one, I discovered that using only 1 battery pack (14kWh / 200A BMS) with a 5kVA Multiplus 2 doen't allow it to start as the transient current is too high for the BMS (fixed values in the BMS are 250A for 30mS, not changeable if you don't want to damage your hardware and loose the warranty).

Is there a known solution to limit the starting current on the Victron side?

Else anyone intending using those BMS in a Victron environement must pay attention to this "detail" and better find another model if they don't intend to have 2 or more battery pack.


jeanmarie asked
klim8skeptic commented ·

0 Answers

How do I set the Input Current Limit to limit both legs of my 120v/240v shore power?

Basically the title. I've searched the forum and found a couple posts asking similar questions with no answers.

MultiPlus II 12v 3000va, a CerboGX, 5kWh lithium, (with a SmartSolar, but I don't think that affects the question) in an RV. I have 50A shore power available at the moment, but I'm often at a place that only has 15A available. I've been able to set the input current limit and use power assist to mimic having access to only 15A, but I noticed the other day that the ICL is only limiting one of the two legs. How do I get it to limit both legs? I get that 15A is single phase, but if I remember correctly from the last time I was limited to 15A (pre-Victron installation), the 50A>15A adapter functionally makes that 15A available to both legs, of course limited to 15A total. So how do I get the input current limit to limit both legs so that the MP draws power from the battery via Power Assist instead of tripping the 15A breaker every 10 seconds? Thanks all!

mattylight asked
mattylight commented ·

1 Answer

Multiplus 24/3000 violates input current limit settings

How do I prevent the MP from exceeding the input current limit settings?

[image]

Stephen Otto asked
derrick thomas commented ·

2 Answers

Multiplus-II AC Input Current Limit -> Per Leg or Total?

I've got a new installation connected to grid power. Does the AC Input Current Limit setting limit power on L1 and L2 individually or does it limit the total amount of power available for L1 and L2 combined?

TIA

jm0278 asked
derrick thomas answered ·

2 Answers

Multiplus2/Bluesolar limited/throttled solar production

System:

2 x Multiplus ii 48/3000/35-32 in parallel

1 x Bluesolar MPPT 150/70

8 x Trojan T125

18 x Renesola 300w panels 6 strings with 3 panels per string

Running ESS feeding excess to the grid.


I started off with 1 multiplus and 9 panels with average output as per graph.

[image]


I then upgraded with another 9 identical panels. The output was capped at just over 2kw.

[image]


And after adding another multiplus it is now capped at 3,6kw from 10am to 2pm.

[image]


Thinking that the inverter current is derated due to temperature as the internal fans switch on at 09:30 in the mornings already with room temperature between 20-23 degrees C, I have installed 2 120mm ac fans on each inverter and another one on the mppt ducting air into the bottom intakes. Before the mppt was almost hot to the touch, and now cool after installing the fan from 10-4pm. The fans made practically no change to the solar output.


MPPT current at the peak readings is 108V and 33A that is just over 50% capacity. At 3,6kw production the inverter is running at exactly 60% of the rated output. Any suggestions as to why production is limited or capped?

wannibi asked
wannibi answered ·

3 Answers

Three phase Multiplus max power

Hi,

I read some messages with a Multiplus overloaded at lower power than nominal power.
I read documents from Victron with max power at 130% of nominal power (during 30min).

So I am looking for installation feedback to figure out what is the real capabilities.

What is the maximum power (for how long) you get from your three phase Multiplus system on DC supply without overload?

Thanks in advance for your help.

Gabriel asked
Gabriel commented ·

1 Answer

multiplus - various questions

Hi,

I'm located in the UK and work from home. With the prospect of blackouts/load shedding/whatever you want to call it - it means that i've been looking at means to stay with power over a duration of 3 hours (as that's what the current rota suggests).

I've been monitoring the consumption of the house for a few months already, so i should have good data on what our house consumes. It's not too much. On a normal day we take about 12 kHw over 24 hours, but this includes cooking (on induction). Our normal load during the day seems to be between 200 and 400watt.

Although the victron systems make me quite greedy, i have realized that a multiplus 800va or 1200va would be enough to handle the normal load (please correct me if i didn't understand this correctly).

But, i wonder a few things:

  • What happens if i do start using more than the multiplus can supply?
  • How is this wired up in a way that it works like a UPS (for the whole house)? Does it mean that all power needs to flow through the device and does it mean that the 800va/1200va is a limit the whole house would be on?
  • To calculate battery size, can i simply take the Ah of a battery and multiple it by the voltage to get the kWh? So for example a 110Ah 12v battery is 1.32kWh ? Of course, it's not 100% effective so you'd end up with (i guess) around 1.2kWh.
  • If i have a multiplus 48v - can i then also charge 24v or 12v batteries?
  • There seem to be different multiplus'es

I am pretty sure about these things from my research, but i just want to confirm here before i start pressing 'order now!' buttons online :-)

-cyclops asked
johnone answered ·

3 Answers

Limit Input Current to 10 A

Hi,

I am looking for a way to limit the Current for a powersupply using my Orion dc dc 12/24-5 as source. The Orion can use more Amps for a short time, but then fails. How can I make sure, it only draws 10A and not any more, even when the powersupply could use more Amps.

I ran out of ideas and found no real solution.

rock2ya asked
rock2ya edited ·

0 Answers

Multiplus ii external current sensor for current limiter

Dear all,

Where can i find the documentation of the external current sensor of the multiplus?

what functions does it has or how it works exactly?

when i set my current limiter to 35A in the multiplus ii and place an external current sensor.

can the multiplus ii draw 45A?

[image]

*yea i know i should change the picture of the multiplus to a multiplus ii :D

marc-heide asked
marc-heide commented ·

1 Answer

Multiplus X 2 and 100A current sensor

Hi All,

We have a single 48/5000 multiplus 2, with ESS and 48V lifepo4 battery in a parallel grid connected system. Also 4kw PV direct to grid with an old school grid connected inverter. Currently we use the victron 100A current sensor connected directly to the multiPlus to drive the ESS instead of an ET112 grid meter connected to the Venus OS (raspi).

The system is working great.


I have 2 questions regarding this if anyone can help.

  1. We want to add a second Multiplus. Can we do so still using the current sensor connected to the master only. If so do we just configure the slave in the normal manner but leave the external sensor fitted box 'unchecked' ? - Or do we need to fit a meter (ET112) ?

  2. Because we are running the current set up using the external current sensor the system thinks it sits between the loads and the grid (see photo) and as such throws up a lot of L1 overload messages. I assume I can ignore these as the L1 does not actually pass through the MultiPlus.


Thanks for taking the time to read my post.

jetstram61 asked
pcbl answered ·

2 Answers

Other power sources than PV for MPPT regulators

MPPT RS 450 data sheets contain the footnote comment regarding the max PV short circuit current: "2) A higher short circuit current may damage the controller if PV array is connected in reverse polarity"

Does this mean opposite that I am able to connect other sources to the PV input. I have a 350 Volt vehicle battery what I could use to support my 48V system over the night. Charging is done with vehicle charger.

There seems no sufficient answer to very similar question 55662. The question seems also interesting for 80V batteries and smaller MPPT Models without galvanic isolation. I know, this is not possible with any PWM regulators. They dont contain inductors for current regulation and their operation relies purely on the PV intrinsic resistance.

https://community.victronenergy.com/questions/55662/about-new-inverter-rs-486000.html


janvi asked
Alexandra answered ·

1 Answer

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