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Vangelis Beligiannis avatar image

AC LOADS readings jumping up and down like CRAZY on Fronius AC coupled when frequency above 50.2V

My system is off-grid and has a Quattro 48/8000 with a FRONIUS PRIMO 3.0 on AC out, an MPPT 150/70 and a CCGX .

When battery is in float (55V) and the Fronius (on AC OUT) is regulated be the frequency (above 50.2Hz) the AC loads readings on the CCGX go crazy! Up and down by hundreds and even thousand Watts.

As soon as the frequency drops to 50 all is back to normal.

Any ideas?

MultiPlus Quattro Inverter ChargerBYDFroniusfrequency
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you wrote " is regulated be the frequency (above 50.2V) "

do you mean 50.2 Hz maybe ?

I seems to me that the fronius output value is much less actuated on screen than the load is. What is the item that provides the load reading ? shunt from a bms ? Or the ccgx calculates it from output quattro data + output primo data ? How does ccgx obtain primo data ? data wire ?

Thank you for your reply. Yes I ment 50.2 Hz.

The Ccgx calculates from the Quattro and Primo output. Battery is controled by Bms. CCGX and Primo are connected on the same wireless access point with utp cables.

franck47 avatar image franck47 Vangelis Beligiannis ·

but it seems to me in reality your load is connected in parrallel to fronius, right ? at ACout quattro you have in parralel Fronius primo & your load. But on ccgx it's not considered like this at all.

Seems Ac loads on ccgx only reflects that is provided by quattro, and then if primo power value is received at a different rate actualisation, you may not be reading values measured at the same time.

as exemple a a said moment ac loads shows 1150W but it's untrue, in fact it can be 11 50W provided by quattro and 450W provided by Primo (but it's reading not actual). and why it fluctuates it's because quattro production does fluctuate between it and the primo, somehow who has to be the energy provider is a bit a battle between the 2.

now why the battery flow doesn't reflect the 1150 pull from quattro onDC is a mystery.

at least we know your ccgs display loads does not reflect the loads because you have measured it by other means. Next thing to do maybe is also to check with a watt meter what does come out from the primo and compare with the readings.

somehow real watt meter analogic with a needle are really the good thing. I personnally have one at my multiplus and I can see what happens very quicky, very helpful. it looks like better have that instead of a ccgx.

2 Answers
petajoule avatar image
petajoule answered ·

What Firmware do you have in your CCGX?
If you have a version prior to 2.54 please upgrade.

What you seem to experience is a well known bug in old VenusOS versions - which I'm pretty sure Victron staff also knows all too well. ;-)

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And if you do have a newer version of VenusOS than 2.54 already installed, make sure your Fronius runs with MG50 network code.

Vangelis Beligiannis avatar image
Vangelis Beligiannis answered ·


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Hi @Vangelis Beligiannis

I think this is due to the slow update frequency of the PV inverters power measurement.

AC loads are calculated as the difference between Victron output and PV input power.

Vangelis Beligiannis avatar image Vangelis Beligiannis Daniël Boekel (Victron Energy Staff) ♦♦ ·

Thank you for the reply. I think that the update frequency has nothing to do with it for the following reasons :

1) It would be still going on when the frequency returns to 50HZ but all is ok after that.

2) As you can see on the video, the PV power is moving from 1600-1900 W but he AC load is jumping from 700 to 2400!!! During this video the real Ac loads (measured by an energy meter in the house) were steady around 1600W. So it makes no scenece.

Please contact me if you need to get in my system and check for your self. Thank you

Hi @Vangelis Beligiannis

I'm sure the update frequency is the cause.

load: 1600W
PV production as indicated by PV inverter 800W higher than really made: AC loads displayed = 1600+ 800 = 2400W

and the other way round.
so when the PV production changes this happens, when production is stable there is no difference.

Vangelis Beligiannis avatar image Vangelis Beligiannis Daniël Boekel (Victron Energy Staff) ♦♦ ·

Thank you for getting back.

If I install a ET112 meter on the PV inverter Will things get better? Or would a CErbo GX be better than my CCGX because of the quicker processor?