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leonb avatar image
leonb asked

Smartsolar RS 450/100 spec sheet confusion

Hello All,


I have studied the spec sheet on the new 450-100 inverter and must say I think its a game changer in a lot of ways, however, the spec sheet is confusing..... for instance:

It says it has a max PV array size of 7200Watts per tracker, but that makes no sense as 8x 370Watt panels with OCV of around 49Volts, will give 390V and will put you squarely in the kinda 450V range. That equates to 2960kWp per tracker?? So, if I add 8 panels per tracker, 16 total it equates to around 100Amp max charging?? Very confusing.

I also dont understand if you can run a string of panels in parallel as it shows a max input of 20A per tracker??

Do you guys maybe know if Victron has developed a calculator for this MPPT yet?

Any help will be appreciated.

Regards

Leon

MPPT Controllers
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3 Answers
Guy Stewart (Victron Community Manager) avatar image
Guy Stewart (Victron Community Manager) answered ·

Hi @LeonB


I can say you are not the only one. It will be improved generally very soon.


MPPT calculator improvements to include 450V models is also in active development.


The 7200W PV array size is a theoretical maximum, not an aspirational target. It will be impossible to actually get there, because panels will be non-optimal in their current/voltage relationship. Nevertheless you can get pretty close...


As with all previous models, the 450V PV input voltage limit is an absolute maximum hard limit that should not be exceeded under any circumstances i.e panel open circuit voltage on the coldest, sun lit conditions.


The PV input current limit is somewhat more flexible, as it applies to the PV input reverse polarity protection. So a PV string providing less than 20A will not damage the MPPT even if the PV string is connected in reverse polarity. Connecting a PV string greater than 20A in reverse polarity will void the warranty, and may lead to a failure.


However a PV string that is connected in correct polarity CAN exceed 20A without damaging the MPPT. So this PV input current limit is less strict than the PV input voltage limit.


In some installations, where PV strings are connected in parallel (to keep the PV input voltage limit under 450V), the current limit may potentially exceed 20A. As long as the polarity is correct, in operation the MPPT will maintain a maximum operational PV input current of 18A.


As an example of a PV array that approaches these limits,


With the 450/100A model there are two trackers, with the 450/200A there are four trackers.


I will use the Victron 305W-20V Mono 1640 x 992 x 35mm series 4a Part SPM043052000


Open circuit voltage of 39.7 V

Max power voltage of 32.5 V

Short Circuit current is 10.27 A


Tropical conditions, minimum low roof temp of 25 degrees.


450 V / 39.7 V = 11.3 panels

11 panels or 3050 W is the limit in a single string on the PV input side to keep under the 450V.


In order to get maximum power from this tracker, the decision is made to connect 2 equal 11 panel strings together in parallel.

These 22 panels together, connected in 11s x 2p will provide:


Maximum open circuit voltage of 436.7 V (11 x 39.7 V)

Maximum power voltage of 357.5 V (11 x 32.5 V)

Maximum short circuit current of 20.5 A (2 x 10.27 A)

Maximum power current of 18A (both panel spec at max power current and MPPT limited)

Maximum input power of 6435 W (357.5 V x 18 A)


There is another limitation, that is the Maximum DC output power per tracker, this is 4000 W per tracker.

So in optimum Standard Test Conditions (STC), there would be some restriction of the solar production.


In reality, panels do not output their maximum potential very often, so it makes sense to oversize on panels to MPPT a bit.


If you had another equal configuration of 22 panels, lets say 22 facing Easterly towards the morning sun, and 22 facing Westerly towards the afternoon sun. You would obtain the maximum the potential yield of the MPPT.


In the middle of the day you would also reach another (soft) limitation, the unit itself can only output a total of 100A at 57.6V, that is 5760 W combined from the two trackers of the 100A model (you get double from the 200A model).


This means in the middle of the day, it is very likely that a considerably amount of PV power would unable to be converted to usable charge power. In this case, 6435 W x 2 trackers = 12,870 W of PV power, would be limited to 5760 W of battery charging power.


This kind of PV oversizing is an extreme example, but when it comes to battery charging, not unheard of. Especially if daytime loads are high, batteries are expensive, or non-optimal solar conditions means peak output is rare.


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leonb avatar image leonb commented ·

Hello Guy,

Thanks for that. It makes more sense now. But will require careful design to get things right with this MPPT.

Cheers


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Riaan Barkhuizen avatar image Riaan Barkhuizen commented ·

Hi @Guy Stewart (Victron Community Manager)


Thanks for the interesting post above. We have recently installed two of the new MPPT RS 450/100 units. They are connected each to a single string of solar panels (8 x JA Solar 455W Mono Perc) per MPPT input. According the the datasheet we are within the operating envelope of the MPPT and would expect that excess energy be limited during times when solar irradiance is high. (Refer to note 3 below on the datasheet)

datasheet-notes.jpg


In practice with the current weather conditions, cloudy with lots of edge of cloud, the MPPT is actually reporting "Error Code: #35 - Input excessive power".

error-log-part.jpg


A quick search of the Victron database reveals a very nice page with MPPT error codes, however the current list on the web skips from #34 - #38. (below is a link to the MPPT error code list)

https://www.victronenergy.com/live/mppt-error-codes


Probably good that I also mention that the MPPT's are on Firmware 1.02, seems to be the latest however a separate file is not available for the MPPT RS 450/100 on the Victron Professional Site for me to actually confirm.


Why is the MPPT not limiting input power to the maximum value of 3500W per MPPT? In practice it overshoots, shuts down for a few seconds then rinse repeat until solar irradiance reduces.


I have also pulled some data from the advanced tab for reference.


Best Regards

Riaan

176 Leonie Str - VRM Portal.pdf

176 Leonie Str - VRM Portal_Zoom.pdf


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Guy Stewart (Victron Community Manager) avatar image Guy Stewart (Victron Community Manager) ♦♦ Riaan Barkhuizen commented ·

Thanks for the info - please also make this enquiry through your dealer if you haven't already - it need to involve them.

If you enable two way communication on the GX device via the remote console in the VRM Portal, you will be do a remote firmware update via the VRM device list (if one is available). I believe the latest version is 1.03. If any of that is unclear, let me know and I will attach some more links explaining.

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Riaan Barkhuizen avatar image Riaan Barkhuizen Guy Stewart (Victron Community Manager) ♦♦ commented ·

Thanks for the prompt response!


Will try the update as suggested.


Best Regards

Riaan

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Riaan Barkhuizen avatar image Riaan Barkhuizen Guy Stewart (Victron Community Manager) ♦♦ commented ·

FW update completed from 1.02 to 1.03, will be able to give feedback during the day.

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mobilcz avatar image mobilcz Riaan Barkhuizen commented ·

I have same issue with firmware 1.03 with 10x300W panels per tracker config...

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Guy Stewart (Victron Community Manager) avatar image Guy Stewart (Victron Community Manager) ♦♦ mobilcz commented ·

For Error 35 issues on RS products,

We are able to reproduce the issue and there is a firmware improvement currently being developed to help prevent it from being reported in cases when it shouldn't be.

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antoncpt avatar image antoncpt commented ·

Hi @Guy Stewart (Victron Community Manager) .


Could I ask a stupid question please?


I have 20x JA Solar 455W panels. Roof mounted at 35%.

- 10 panels face dead North-East.

- 10 panels face dead North-West.

450/100 MPPT controller.

4x lifep04 batteries.


The max I have seen in the VRM as they show both the same voltage and amps from 09h00 - 15h00 at max is:

tracker 1 ~ 220v @ 10 amps = 2200w

tracker 2 ~ 220v @ 10 amps = 2200w

The max watts in the VRM that I get from the panels is 4200w - 4400w throughout the day. In the morning its 2000w 07h50 - 09h00 and the evening from 16h00 - 17h00 its 2000w also, but drops to 1000w(x2) after 17h00 on both trackers. This is now in early spring from the 1 - 7 September 2022. Both the trackers almost always have the same output.


My question, it feels like its half the power, should I not get close to 450v per tracker? or is the 450v total for the whole system? In other words should I not get close to the 9100watt(-25%) for all the panels combined? I know its not summer yet.

Or is the system operating as it should and the max that I can expect now is around 4000-4400w? The sun is in its full bloom, Cape Town, South Africa.

Under overall history, of the MPPT the max voltage is 248,99v.

Should I not expect something close to 400, 450v?






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Alexandra avatar image Alexandra ♦ antoncpt commented ·
@AntonCPT

The mppt will track the panels at their max power point for the temperatures they are operating at.

The 450V is the max input you can put into the trackers at minimum temperature. However in use you size the array VOC to 8x your float voltage for your batteries.

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antoncpt avatar image antoncpt Alexandra ♦ commented ·

Hi, sorry I am confused. OK lets approach this with another example.


The main question is what can I expect in total watt under perfect conditions, like lab conditions with the Victron 450/100? I am just trying to find out if my solar setup is setup correctly.

Looking at my MPPT I am only seeing a max "hard limit" of 4000w out of the system. The total wattage, I am expecting more in the 6000w range. Why do I say this? Because I see both strings are fighting for max wattage. Just now I observed it again. String 1. will be at 2700w and string 2. at 1300w, then all of a sudden in a few seconds later String 1. will be 2000w and string 2. will also be also at 2000w. Its like the MPPT is hard limiting the wattage at 4000w. As said I am expecting much more.


This is a copy and paste from VRM.:

PV Charger

3907 W (TOTAL WATT)

MPPT 450/100 HQ2204TR2J2-#1 220.87 V 9.30 A 2054 W
MPPT 450/100 HQ2204TR2J2-#2 219.42 V 9.37 A 2055 W










Also I noticed the installer set the max charge on the MPPT to 80amps? That means it 20amps per batttery? A battery can handle 50amps. It is actually recommended on the battery spec sheet. So it needs to be 200, but I know the MPPT is limited to 100, right?


Lets for argument sake use 'lab conditions' @ 1000wm2

8x hours of perfect "lab condition" sun/irradiation.

What should the max wattage be that I should see on the MPPT? Not total for the day, but at a given moment of perfect sun shine.


Should I not see something like so?

#1 | 440v | 10a | 4000w

#2 | 440v | 10a | 4000w

Total of 8000w,

but expecting more in the 6000w - 7200w range?










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nickdb avatar image nickdb ♦♦ antoncpt commented ·

At 100A and typical battery voltage of, say, 54V it would be 5400W.

Less if the voltage is lower.

At 80A you’re stuck at 4300W.

If you’re expecting 6000W your mppt is too small.

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nickdb avatar image nickdb ♦♦ antoncpt commented ·
Editing posts makes it difficult to follow. @AntonCPT your mppt is too small, even worse because it’s output has been hobbled.


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antoncpt avatar image antoncpt nickdb ♦♦ commented ·
Could I increase the charge voltage to 100? Since that would be the limit right?
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nickdb avatar image nickdb ♦♦ antoncpt commented ·
You mean charge current. Yes, should be fine. In a typical system charge/discharge current is limited by the battery bms and dvcc anyway - assuming yours is connected and setup to best practice.
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antoncpt avatar image antoncpt nickdb ♦♦ commented ·

So Nick, I changed it to 100 on the MPPT, I am getting 5000w! :) which is great. I can upped it to 120? Or should I leave it as is for now. That is in total with consumption with other devices in the home.

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antoncpt avatar image antoncpt antoncpt commented ·

PV Charger

5061 W


battery:


Charging1401 W

86.0 %


Voltage50.40 V

Current27.80 A

Temperature22 °C


MPPT 450/100 HQ2204TR2J2-#1 209.82 V 12.87 A 2700 W
MPPT 450/100 HQ2204TR2J2-#2 206.97 V 12.97 A 2684 W
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antoncpt avatar image antoncpt antoncpt commented ·

https://www.solarpanelenergy.co.za/docs/Dyness%20BX48100%20Specification.pdf

The battery charge is recommend at 50amps anyway and I have 4x of them, master, slave, slave, slave/


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nickdb avatar image nickdb ♦♦ antoncpt commented ·

Thats just an error in the UI. The mppt is hard limited to 100A.

The larger RS runs to 200A with 4 trackers.

You’re “losing” power because you have batteries with a lower nominal/charge voltage, which doesn’t help.

Personally I would either upgrade the mppt or replace it with two smart solar mppts with a higher combined output rating. Your installers have done you a bit of a disservice.

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antoncpt avatar image antoncpt nickdb ♦♦ commented ·
Thank you Nick for all your help and answers, truly appreciate it. You the only one that actually given me the correct answers since install. Thanks again!
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antoncpt avatar image antoncpt antoncpt commented ·

MPPT: You know what I think the problem is... I think the installer thought that the "charge" must be at 80a for the batteries, but that is anyway to low. That 80a is the supply to the whole system batteries and critical load included. That is why I am getting 5200w now with the aircon on and batteries charging. Where i used to get only 4000. The MPPT is actuall controlled via the Battery BMS as I understand it. The "external control". So when they set it to 80a they limit the whole solar input to only ... 80a. Then I need to ask, is this how it should be setup? Because it feels to me that the MPPT should put out max to the 2x Muilti 5000 and the battery should "grab" what it needs at its set max charge.


My batteries are actually fully charged right now at 12h20, where it usually is at 13h40. So tomorrow it should actually be fully charged at around 11h30. And the temp of the batteries idles at 22c which is great with the adjustment.

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nickdb avatar image nickdb ♦♦ antoncpt commented ·

If you open your remote console on the GX, navigate into the battery's bms entry. There should be a parameters tab, in there you will see DCL and CCL, which are the charge and discharge current limit the battery sends to the system.

You didn't mention which batts you have, but most should send this data to the GX.

Under external control the batteries will only consume what is required, generally this is way more than your solar can provide anyway.

In any case, solar is prioritised for loads, what is left goes to the battery.

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antoncpt avatar image antoncpt nickdb ♦♦ commented ·
Thank you nick, sorry needed to update it. I had a feeling that MPPT is too small... that is what they sold to me.
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peyper avatar image peyper antoncpt commented ·
Hi Antoncpt,

I am also about to install a RS 450/100 with +- 11 900W solar panels, 2 x Multiplus II 48/5000 and solar MD 14.3kWh. Can we chat perhaps? My WhatsApp number 071 255 1977. I am from Durbanville.


Regards

Johann Peyper

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nickdb avatar image nickdb ♦♦ peyper commented ·
That mppt is too small for that. Please use the mppt sizing calculator.
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Alexandra avatar image Alexandra ♦ peyper commented ·
@Peyper

I second this you would need at least the 450/200 or use the online calculator.

check out the free training videos on victron professional .

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nickdb avatar image nickdb ♦♦ antoncpt commented ·
One last point. Coastal town, non-optimal orientation. You’re probably going to lose about 30%, regardless, before you factor in loss due to summer heat (when it arrives).
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antoncpt avatar image antoncpt nickdb ♦♦ commented ·
Ok, thank you. Yes if I even just get ~6000w I would be happy. Because I did over sized a bit for the winter months, but 4000w seems way to low.
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Alexandra avatar image Alexandra ♦ antoncpt commented ·

@AntonCPT

With the Dyness you wont see 6000w. As it will produce 100A x battery voltage as yeild. Dyness are typically lower voltage batteries.

And as @nickdb mentioned irradiance affects it as well. If you have over panelled the thumbs up. But also do t forget solar panel makers rate their panels at not world conditions even the NOCT values are higher than real world yeilds. 800W/m² i have never seen on our best day we see 5.75w/m² so about 70% of installed wattage of panels.

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secz avatar image secz commented ·

Hello @Guy Stewart (Victron Community Manager) ,

thanks for your insightful article.

I would like to oversize my system to set it up for a high winter yield.

I have

24moduls = 2 strings of ( 6(row)*2(parallel))* Axitecmodules 405W each.

37,3 Voc, 13,81 Isc

31,4 Vmpp, 12,9 Impp

All this on SmartSolar RS450/100


Batteries Pylontech US3000c

Float voltage 51V according to Victron.


The Isc is with 27,62A over the limit.

Is it possible to install it this way?

I ensured that polarity is right.

Regards from Germany
Sebastian

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leonb avatar image
leonb answered ·

Hello @Guy Stewart (Victron Community Manager).

I am busy installing 2 systems in Zimbabwe. Both with 450-100's, Freedom 15-12, CCGX and Multiplus inverter.

System 1 I got up and running ok. System 2 MPPT just will not fire up. I can see it on Victron connect, and on CCGX, but it wont open to deliver any power from panels......

What I have tried:

1. Disconnected comms cable from FW, no difference.

2. Reset, MPPT to factory default in Victron Connect and reprogrammed.

3. Shut everything down, restarted, no change.

Eventually I managed to get 300W from panels, and it shows on VictronConnect but not on the CCGX???

I am lost, please assist.

Regards




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alan avatar image alan commented ·

What is the remote mode set to in VictronConnect? Try remote on/off with the factory link in the the io plug.

ae024b12-4d36-4a49-9e47-4f1fb8cd1aad.jpeg

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antoncpt avatar image
antoncpt answered ·

That one little change made all the difference, setting it to 100a on the mppt.

The total watt output with batteries charging + appliances reaches about 5900w, it idles at around 5200w. I even saw the solar spiked at 8100watt somewhere.

The 4x batteries are charging in total at 3200w max, which is under their recommended charge rate of 0.5c. I think the BMS is controlling this. The rest is for appliance use.

Happy chap right now.

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antoncpt avatar image antoncpt commented ·

screenshot-20220925-124225.jpg

screenshot-20220925-123915.jpg

Screenshota

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