question

jimbo avatar image

AC coupled STATE 453 Short term grid voltage error

Hi, we have two similar systems on the property. One works well, the other does not.


1 x 5K coupled Primo/Multiplus (works)

1 x 3K Coupled Primo/Multiplus (never has worked well)


The 3K Multi makes a very odd crunching (humming) noise when charging (as soon as the primo is turned on). The MP begins to charge then the primo shuts down with various error codes (Error 456) being the most common.


NOTE: it does not make the same sound when charging form the AC input (Geni)


The MPlus has the PV assistant installed as per Victrons recommended settings. The sound the MP inverter is making sounds very unhealthy, but it's made it since day one and I was advised by the sales rep that it was not an issue. The 5K system has never made a sound.


I have just updated the Multi to the latest Firmware version to no avail.

I also changed the Primo to MG60 and updated the MP and Assistant to 60Hz settings again with no difference in functionality


One note is that since updating to MH60 the pitch of the odd charging "crunch
sound has lifted in frequency.


Looking for some advice, please. This is very very odd behaviour indeed.


It feels to me like the MP is sending out bad info to the primo and making it consistently reboot.


MultiPlus Quattro Inverter ChargerAC PV CouplingFronius
fronius.jpg (83.2 KiB)
5 comments
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Will need some screen shots of your setup

the grid type selection thats been set

The size of the PV array

the firmware version you are on

a screen shot of all the setup parameters

were have you connect the Grid tie inverter to IE AC1 out or AC1 in

have you got this unit connected to the vrm if so please provide access details in a private reply message

Hi Paul.

ScreenShots to follow:

The Primo is set to MicroGrid60 and the Multi is set up for 60Hz with the PV assistant set up with the settings to suit 60Hz.

The firmware version is 2612473.vff

Fronius Primo is connected to AC1 out (AC1 in is a geni)

Unit is not connected to VRM unfortunately as it's way out in the bush.

PV array is 3KW one string.


sound file attahched.Limestone Road 18.m4a

limestone-road-18.m4a (540.2 KiB)

Hi Paul, I seem to have isolated the issue!. It appears to be something to do with the two fuse boxes. Not sure what exactly. I have disconnected the Outhouse FB and it seems to be much more stable. Perhaps because the two boxes are MEN? or because the outhouse GPO RCBO is sitting after before the Multi CB?


I'll try a different configuration tomorrow when I have more time. and report back on my findings unless someone can see something blindingly obvious that I'm missing.


froniusfb.jpg (150.1 KiB)

The Fronius state is complaining about the grid frequency.

jimbo avatar image jimbo Riaan Barkhuizen ·

hi Riann, yes I understand that, I am trying to ascertain why, given its an ESS system. No actual grid.

1 Answer
Paul B avatar image
Paul B answered ·

I cant see the video in its current format on my machine. screen shots are better. es[peciall of the assistant settings. and a proper diagram of the setup.


however

I suspect that this is occurring when the batteries are full, when the batteries are, and the loads are lower than whats being generated from the solar and grid is disconnected . then there are a few things that can happen.

1 the mains is disconnect or not there

2 the av voltage can climb out of spec

3 the dc battery voltage can climb out of spec


so to stop this happening the ess raises the Freq from say 50hz to 53hz and the grid tie solar units are then suppose to TURN OFF depending on there settings.

there are also other ways as well so it depends on whats installed and how its all connected and interfaced, you should get good advise on how to do this setup. or you can do a lot of damage.

It could also be why the unit is making funny noises.


Anyway make sure that the grid tie units are turning off when they are suppose to.


so do the tests.

and what the voltages and the grid tie units when the batteries ar full and the load is low witrh plenty of solar.



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Hi Paul, thanks for the input but no this is not occurring when the batteries are full. The MultiPlus is not frequency shifting to turn the Fronius off. The 5K system I have works like this (as expected) and shifts Hz to stop the Fronius from charging using the PV assistant.


This 3K setup is doing very odd things indeed. when the unit works independently from the grid-tie Primo it works fine and the voltage is stable at 229.1V also makes no noise. As soon as the Fronius is powered up and introduced to the mix the voltage begins to fluctuate from 228-230.2V and the Multi Plus begins to make the crunching humming sound.


Is this voltage fluctuation due to the charge being sent to the Multi? is this expected behaviour?


I can't isolate the Fronius to check the voltage output as it needs 240V to power up.... is there a way I can rut it from the DC input only?


I have added a quick diagram to the original post.


thanks


J

Hi There,

The crunching humming sound is the frequency shifting (this is normal sound), can you test the system with half solar capacity or is this a 1mppt fronius?

Best regards
Riaan


jimbo avatar image jimbo Riaan Barkhuizen ·

Hi Riaan,

I have been testing all day today with reduced 2Kw and the Primo still shuts down with an error and reboots. I kept missing the error code but will endeavour to catch it tomorrow. I just compared the 3KW Multi settings to the 5KW system running here and they are exactly the same settings so should be working.

The Fronius is a 2 MPPT but were only using one string so the two MPPT's are bridged as per Fronius install instructions.

The 5KW multi makes no sound what so ever it's silent operation why is the 3KW so so noisy in comparison?

and is the fluctuating voltage normal behaviour under charge?

jimbo avatar image jimbo Riaan Barkhuizen ·

updated the image as I forgot to add the AC ISO between the Fronius and the MP