1 minute ago, plonkster said:

I doubt it. The Goodwe isn't THAT bad. Must be a configuration issue.

That would be 1st prize for me, but the settings for it on the app consist of basically 15 odd settings, most of it around voltage limits on the battery and W feedback to the grid, so am really hoping there is a hidden super user menu or something somewhere

So got feedback from the Inverter guys, they were really quick which I am quite impressed by. What they did say is I should have a Neutral-Earth bridge on my side, and that will solve the floating voltage issue.

So, looking at the diagram they send me , it looks like all I have to do is bridge the Netrual and Earth bars before the RCD, so will do that and see if that solves my tripping issue. Not sure why the installers didnt do that, as apparently it is already required for generators and is likely to be required in future anyway

 

20 minutes ago, Ddeclercq said:

bridge the Netrual and Earth bars before the RCD

If you do that... you can't have an RCD before the inverter. While in bypass, any bond downstream of an RCD causes it to trip. You'd have to feed the inverter with power that is not RCD protected. This is allowed btw...

What is not allowed is a second PEN (protective earth neutral) bond. Some people simply do it that way, turn a blind eye to the slight issue of working current on an earth wire... and away they go. But technically you are not allowed to bond it a second time, cause when running off grid you will then have two bonds.

That's why other inverters use a bonding relay. The bond is established only while running disconnected from the grid.

Right, I got some info from a local Goodwe fan. You have to bridge all the earth's together. This is good practice anyway, even for other inverters. Always go a little overboard with your earths.

Note also in the aus/nz figure where the neutral is bridged across input and output. Long story short... there are tricks to this inverter that the installer needs to know about. It is possible that this inverter does not do its own bonding.

(Technically, for those in the know, if it needs the neutrals bridged like that, it possibly doesn't comply with at least earlier versions of SANS-10142-1, since it relies on the upstream bond. Or in other words, if you open the main double pole isolator for your house you lose the bond...).

On 2019/12/14 at 11:08 AM, plonkster said:

Right, I got some info from a local Goodwe fan. You have to bridge all the earth's together. This is good practice anyway, even for other inverters. Always go a little overboard with your earths.

Note also in the aus/nz figure where the neutral is bridged across input and output. Long story short... there are tricks to this inverter that the installer needs to know about. It is possible that this inverter does not do its own bonding.

(Technically, for those in the know, if it needs the neutrals bridged like that, it possibly doesn't comply with at least earlier versions of SANS-10142-1, since it relies on the upstream bond. Or in other words, if you open the main double pole isolator for your house you lose the bond...).

Thank you. All the earths were connected together put as you pointed out the DP Main switch broke the bond. So I ended up connecting the N-E on the DB board on my side before the RCD, and no negative effects, and I don't have a floating voltage anymore when I switch off the grid. So when the next round of load-shedding starts I will see if it made any difference. I also removed all the surge protector plugs in the house, hoping the surge protector on the incoming feed before the RCD would do the same thing without tripping issues associated with them