question

Hooky avatar image

Could a Quattro backfeed Ac to Generator ?

Off-grid-DC Coupled-3x Smartsolar 250/100 1x Quattro 15kva, 5 x 13.8pro BYD , 20 Kw PV, 50 Kva 3P converted to 35 Kva 1P Generator.

Generator connected to AC input 1 in Quattro,Discoved generator has blown its diodes.

Is there any way the Quattro may have back fed Ac to the generator and caused this ?

@Guy Stewart (Victron Energy Staff)

@mvader (Victron Energy Staff)

GeneratorBYD
10 |3000 characters needed characters left characters exceeded

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

6 Answers
bitcrusher avatar image
bitcrusher answered ·

normally not - there is a backfeed relay that is open as long as inverter is running.

Share
10 |3000 characters needed characters left characters exceeded

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

WKirby avatar image
WKirby answered ·

When the generator is running the backfeed relay will be closed otherwise the energy from the generator will not go anywhere.

If the AC-1 input type is set as a generator input then it should not backfeed.

https://www.victronenergy.com/live/ess:design-installation-manual

Make sure your LOM settings are correct.

https://www.victronenergy.com/live/ve.bus:grid-codes-and-loss-of-mains-detection

Share
10 |3000 characters needed characters left characters exceeded

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Guy Stewart (Victron Community Manager) avatar image
Guy Stewart (Victron Community Manager) answered ·

It is possible for this to occur, and moreso likely when there is a large AC solar inverter, and lithium batteries. This could occur for instance if you were running the generator to charge the batteries, and there was a flash of solar on the AC solar inverter and AC current pushed into the system exceeded the batteries ability to absorb and the generators and solar inverters ability to respond quickly to the new condition and command from the CCGX/Multi.

I made some comments about ways to program the Quattro to prevent this from occurring, by isolating generator from AC solar inverter so they cannot overload each other.

https://community.victronenergy.com/questions/715/froniuscolour-gxquattro-byd-generator.html

1 comment Share
10 |3000 characters needed characters left characters exceeded

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

That makes sense, also because the PV cystem is 20kWp for a 15kVA quattro (assuming it's a 1 phase system).

Hooky avatar image
Hooky answered ·

Sorry I should have mentioned the system is DC Coupled, the generator is a 50 Kva 3 phase -converted to single phase and the secondary generator has been running for 100 hours and not had an issue with no changes to the system settings.

No alerts are alarms are visible in the log when the diodes burnt out either.

We are having trouble with the generator supplier fixing the diodes under warranty and really need help convincing them that the Quattro has no way of causing this damage.

Share
10 |3000 characters needed characters left characters exceeded

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Guy Stewart (Victron Community Manager) avatar image
Guy Stewart (Victron Community Manager) answered ·

The next thing that I would check is the Advanced history of the system on VRM.

The specific field would be AC input voltage and current.

This should provide the necessary information and even used as evidence to your generator supplier that there is no negative current returning to the generator.


This is a system operating off a generator with no back feed, only consumption from the gen to the system. You can see current never drops below 0.


This is a grid connected ESS system which is exporting some DC solar back to the grid. You can see current is both above and below 0, between 5A and -10A.




Share
10 |3000 characters needed characters left characters exceeded

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Hooky avatar image
Hooky answered ·

Thanks @Guy Stewart (Victron Energy Staff)

We have checked the advanced and have nothing showing.

Would you then agree this would only happen with AC coupled system and not DC Coupled?

Share
10 |3000 characters needed characters left characters exceeded

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.