Vm-3p75ct showing to low power/amps, maby powerfactor problem?

I have built a system for a customer. Been running for 2 months. It is Cerbo GX, 3-phase Multiplus-2 5000va, 64kwh, VM-3p75ct, 3x Fronius Symo 10kw, Fronius Smartmeter.

Fronius is one of the units Master and the other two slave. The property has 3x20A main fuses to the electricity grid. Fronius connected to Cerbo GX, both pv production and feed-in limit. Fronius smart meter is only as a backup limit in case cerbo gx loses contact.

VM-3p75ct shows very low power factor on many occasions. I have triple checked the CT placement, also tried changing their physical location. And also powerfactor is +0,9 and second after -0,9. No loads in the house are active.

At one point when I was there, the VM-3p75ct showed 15.4A on L1 while the Fronius Smart meter sitting right next to it showed 28A on L1, shortly after the main fuse at 20A blew. The consumption figure is also completely wrong, probably because VRM sees what Fronius gives and doesn’t think it goes out to the grid, so it assumes that it must be consumed in the house? But the numbers don’t add up either, 5839-4724= 1115w not 2373w. I guess it’s the Powerfactor that’s causing this?

This was today:

Did you sort this problem out?

Not too sure about the L1, L2 not adding up. What GX firmware are you running? 3.67 was stable, but 3.7x may have introduced some problems in this respect. Try downgrading to 3.67, and wait for 3.8x before upgrading again.

How have you come to this conclusion?

Well Victron Community isn’t always reliable, depends who’s posting, but I’ve seen this one and one about peak shaving with v3.73…

It may not be relevant, but could be worth a try - backdating to v3.71 or v3.67. Easily reversed if it makes no difference.

I am always wary of starting rumours and myths, the community is not a good barometer for bugs. > 90% are local issues relating to config or installation.

Major issues with supported and tested gear, such as Fronius, tends to be found fairly quickly.

If anything, there have been way more software fixes for issues in current versions, but some issues experienced actually do not reside within the venus OS to start with (DESS logic for example).

Sure it doesn’t hurt to rollback/forward. If I had $1 for every “bug” found after upgrading only to find it still exists when rolling back..