I had a 8kw Sunsynk inverter, battery and 24 (12+12) 250w pv panels installed by our local sparky. I am also not to bad when it comes to electricity but where me and sparky differ is I want stuff done by the book and according to the manual nevermind how many systems you installed. 

So the install went good without a hitch but then i started to read and wanted to correct a few things. 

Sparky took the supply to the inverter after the main breaker in the main DB (that has surge arrestor after the earthleakage and a earth neutral bond on top of the earthleakage) to a sub DB that has another breaker and a changeover and another surge arrestor

My argument is that the inverter has a metal case so it should be protected by an earthleakage, so I moved the supply to the bottom of the earthleakage and installed a earth neutral bond relay in the inverter on the ats port. (misread the specs of my relay and installed a 110vac coil relay) ticked the signal island mode setting and everything worked 100%. Return from the inverter also returns through a main breaker and then a second earthleakage before it goes to the loads. Solar panels also first goes through a fuse and surge arrestors before it goes through a breaker and then to the Invertor. 

The there was a storm one night and the main earthleakage tripped. That night still I tried resting the earthleakage but as soon as the inverter switches from battery to grid the earthleakage trips again. After struggling for a while i tripped the pv panels and the the inverter switched to grid without tripping the earthleakage. Switched on the first pv string and everything stayed on, but when switching on the second string sparks came out the top part of the inverter and the earthleakage tripped again. Then I found that I used the wrong relay (110vac instead of 220vac). But confident in my heart that there was a issue with the second string I left it off and the next morning before the sun rose I disassembled all the panels from both strings in search of the issue but not finding anything I assembled everything exactly like it was and switched everything on with no sparks. (removed the 110vac relay so there was no bond after the inverter) 

Baffeled we continued like this for a day or 2. Then There was another storm and loadshedding but when the grid came back the earthleakage tripped. Suspecting that it could be that there was no bond after the inverter I installed a time delay relay directly on the grid supply to the inverter (after sparks flied in the inverter the ats port constantly supplied 220vac no matter if grid was on or of or even if the setting was tucked or not) so when grid came on it delayed for 30sec and then broke the load bond and should grid go off the relay immediately creates a load bond. After installing the delay relay the inverter still tried the earthleakage when switching from battery to grid. Tripped the pv panels then The inverter can switch to grid with no issue. (panels, inverter, battery is earthed). When grid is switched of and inverter is trussing from the battery I can switch on the pv panels and everything works fine. 

I then moved my supply to the inverter to the top of the main earthleakage and then I can switch on everything with nothing tripping. 

So my question is, should your supply to your inverter go through an earthleakage? This issue only happens when there is a storm when everything is wet but I cannot find a broken seal on any of the Mc4 connections. 

Your advice and comments on my relay mistake would be greatly appreciated. 

8 hours ago, SwitchVanDam said:

Solar panels also first goes through a fuse and surge arrestors before it goes through a breaker and then to the Invertor. 

 

So my question is, should your supply to your inverter go through an earthleakage? 

Your advice and comments on my relay mistake would be greatly appreciated. 

Solar panels First through DC breaker then to fuses.

Supply to inverter not after Earth Leakage Device.

12 minutes ago, Virwat said:

Solar panels First through DC breaker then to fuses.

Supply to inverter not after Earth Leakage Device.

Thanks for the reply and advice. I just want to challenge your advice, if you are correct by taking the supply before the earth leakage why is there a signal island mode function? If supply is taken before the earth leakage then there can be a permanent earth neutral bond on the inverter load and nothing would trip and also then no use for such function. Isn't there maybe a diffent fault that I should search for that would be the better solution or am I just being stubborn? Thanks again for your reply, I am just trying to get clarity and not just follow any advice without understanding it. 

Your output from inverter supply feeds an earth leakage device for essential circuits and your existing earth leakage device feeds the non-essential circuits.

If you don't have split circuits, then all circuits feed from the earth leakage device that is fed from the Inverters load side.

Island mode is the same as if you are completely off grid with NO connection to the grid.

Then you must install an EN bond for your output from inverter before the earth leakage device. 

There is a lot of switching and relay devices inside that inverter that is doing lots of different functions btw.

1 hour ago, Virwat said:

Your output from inverter supply feeds an earth leakage device for essential circuits and your existing earth leakage device feeds the non-essential circuits.

If you don't have split circuits, then all circuits feed from the earth leakage device that is fed from the Inverters load side.

Island mode is the same as if you are completely off grid with NO connection to the grid.

Then you must install an EN bond for your output from inverter before the earth leakage device. 

There is a lot of switching and relay devices inside that inverter that is doing lots of different functions btw.

Yes you are correct I have 2 seperate curcuits for essential and non essential loads. 

But my issue is what protects my inverter? Should there be a fault inside the inverter with all those relays and switches what is going to trip before everything goes up in flames? We also have allot of lightning storms and I am of the opinion that the earthleakage provides some sort of protection against it

The EL is not there to protect any equipment. It is only there to protect the human user. The breakers are there to protect the cabling in your system.

If you have 2 EL's in series you are prone to nuisance trips. 

1 EL on the non essential system and 1 EL after your inverter. That is how I was taught.  The E neutral bond is only there because if you switch off the mains there is no bond at the main transformer in the street.

Okay lets say there is a fault inside the inverter and somehow there is a leak to its metal body and you as a human touch that metal body you are going to get a shock or not?

24 minutes ago, SwitchVanDam said:

Okay lets say there is a fault inside the inverter and somehow there is a leak to its metal body and you as a human touch that metal body you are going to get a shock or not?

If the inverter is earthed, no. Earth leakage is an enhancement on this protection, especially where plugs are involved.

7 hours ago, Vaal said:

The E neutral bond is only there because if you switch off the mains there is no bond at the main transformer in the street.

The N to E bond at a transformer is permanent. It is not affected by you switching off the main switch. It does however disconnect your N from the supply N which is earthed. 

@frivan if the transformer earth conductor is stolen like most pole transformers you will get shocked.

@SwitchVanDam

So it seems like everyone agrees. Supply to inverter should be before the earthleakage. 

Secondly. Does everyone agree that my pv panels are okay taking into mind what happend?

Also noticed that when I switch of the dc breaker of the panels and measure dc volts between + or - of the pv panels and earth I get close to 200v and while I am holding the meter there the volt decrease to around 20v

Is this normal? 

Edited February 29, 20242 yr by SwitchVanDam
Spelling

13 minutes ago, SwitchVanDam said:

So it seems like everyone agrees. Supply to inverter should be before the earthleakage. 

Secondly. Does everyone agree that my pv panels are okay taking into mind what happend?

Also noticed that when I witch of the dc breaker of the panels and measure dc volts between + or - of the pv panels and earth I get close to 200v and while I am holding the meter there the volt decrease to around 20v

Is this normal? 

Cannot comment on the 200 to 20V as there is no capacitor on the panel side. Such a voltage dropping slowly is normally a capacitor discharging. 

At least the E/L is sorted. My reason is that there are discharge leakage current in the inverter and that is why the inverter input is not through a E/L. 

16 hours ago, Scorp007 said:

if the transformer earth conductor is stolen like most pole transformers you will get shocked.

If the neutral to earth connection on the premises is in tact, you won't get shocked.

2 hours ago, frivan said:

If the neutral to earth connection on the premises is in tact, you won't get shocked.

Bear in mind that your munic earth on most premises are not earthed locally but only  at the transformer. Also no E to N bond. 

We talking here of the transformer's earth to neutral that gets removed for scrap copper. Thus the neutral is floating. 

 

Edited February 29, 20242 yr by Scorp007