I just have a quick question that I'm would like to ask here before asking my installer.  Just so I have a better idea about what is going on.  I fear they might make it out to be nothing.

I've had my parallel 5.5kw Sunsynk setup for about a year now without any problems really.  It is your standard grid tied setup with panels and batteries.  Today I was changing a light fixture with all the lights breakers turned off and get a shock from the neutral wire.  I measured it and there was about 110v between E and N.  In hindsight I should have just completely disconnected the power but the wife unit would not approve the request.

Anyway, after a few more tests it seems to me the problem is coming from one of my inverters.  When I measure from the chassis of my master inverter to ground I get the same 110v.  That's with Eskom switched completely off.  There is no voltage on the slave inverter chassis.

Any idea what it might be?

1 minute ago, CptH4ppy said:

I just have a quick question that I'm would like to ask here before asking my installer.  Just so I have a better idea about what is going on.  I fear they might make it out to be nothing.

I've had my parallel 5.5kw Sunsynk setup for about a year now without any problems really.  It is your standard grid tied setup with panels and batteries.  Today I was changing a light fixture with all the lights breakers turned off and get a shock from the neutral wire.  I measured it and there was about 110v between E and N.  In hindsight I should have just completely disconnected the power but the wife unit would not approve the request.

Anyway, after a few more tests it seems to me the problem is coming from one of my inverters.  When I measure from the chassis of my master inverter to ground I get the same 110v.  That's with Eskom switched completely off.  There is no voltage on the slave inverter chassis.

Any idea what it might be?

This is how it should be when the N-E link is not installed and running from batteries if I remember it. When the grid feeds the N it will be close to zero on the N unless the grid E-N link is faulty or not tight.

3 minutes ago, CptH4ppy said:

I just have a quick question that I'm would like to ask here before asking my installer.  Just so I have a better idea about what is going on.  I fear they might make it out to be nothing.

I've had my parallel 5.5kw Sunsynk setup for about a year now without any problems really.  It is your standard grid tied setup with panels and batteries.  Today I was changing a light fixture with all the lights breakers turned off and get a shock from the neutral wire.  I measured it and there was about 110v between E and N.  In hindsight I should have just completely disconnected the power but the wife unit would not approve the request.

Anyway, after a few more tests it seems to me the problem is coming from one of my inverters.  When I measure from the chassis of my master inverter to ground I get the same 110v.  That's with Eskom switched completely off.  There is no voltage on the slave inverter chassis.

Any idea what it might be?

Your installer is supposed to entertain a Neatral to Earth Bonding relay.  However this bond is only activated when the grid collapses. If that 110vac is even there when the grid is available, then the grid input neatral is at fault, but thats unlikely. 

 

Just to be clear.  This happens when Eskom is on or off. And I am measuring from one of the screw holes on the front of the inverter.

Maybe we should ask the Sunsynk Gurus to help. 

When input grid is available, does the grid neatral pass thru to the essentials neatral, within the machine.? 

The reason im asking is the OP sits with a floating neatral even when grid is available. 

43 minutes ago, BritishRacingGreen said:

When input grid is available, does the grid neatral pass thru to the essentials neatral, within the machine.? 

You are correct in your assessment, he needs an E-N bond relay. His RCD will also not be working when grid is down, so not only is this installation non-compliant, it's also really dangerous.

A little more feedback. There are 4 seperate breakers at the inverters. 2 for input and 2 for output. Even with them all down so there is no power in and no power out to both inverters I still measure the voltage on the primary inverter chassis.

There is a 2 pole contactor in place that Im guesing is for the E N bond. I can hear it disconnect after turning eskom back on after about 30 seconds. 

In that case you might be missing the earth bond to the chassis:

5 minutes ago, P1000 said:

In that case you might be missing the earth bond to the chassis:

I think this is probably it. There is no ground wire connected under the chassis like the one in your picture.

Thanks for the help.

That same earth mandatory pic that was shared by P1000 refers: That external Earth is connected to the main Earth busbar internally. So if the earth of the machine internally was connected, that external earth would not really be required. I think before jumping to conclusions of high proportion please take a pic of the inside earth connections and make sure they make good contact. Im willing to bet that there has been some skipped Earth connections. But the N to E Bridge relay is very important. 

1 hour ago, P1000 said:

You are correct in your assessment, he needs an E-N bond relay. His RCD will also not be working when grid is down, so not only is this installation non-compliant, it's also really dangerous.

I know someone also without an E-N bond relay ,it seems not many installers do these. Interesting thing is when grid is down his essentials RCD does work when you press the test button. Why would that be ? I did confirm the floating voltage of 110V with a multimeter .

Remember the button is a self test and not a real test. For that you need and Earth leakage tester to be plugged into a socket.

@Nexusswell spotted. The RCD press to test is not the definitive test. One of these devices will actually carry out a proof test. 

I'm willing to bet there are many Sunsynk installs in the wild without the N to E bridge & to make it worse, the customer does not know because the machine is fully functional but not necessarily safe. 

This is a major deficiency that I see because the humble Axpert has this feature built in, but it seems the SunDeye does not & thats really ok for installations in the UK or elsewhere where regulatory affairs are in good order. However, here in the wild west of SA we have a struggle with all things written to follow...Let's just say that what is written & what is carried out is a sometimes not the same. 

8 minutes ago, Nexuss said:

I know someone also without an E-N bond relay ,it seems not many installers do these. Interesting thing is when grid is down his essentials RCD does work when you press the test button. Why would that be ? I did confirm the floating voltage of 110V with a multimeter .

The self test does not test to earth, it test if it detects residual current. Remember, the RCD does not have an earth connection. So the test button connects neutral after the RCD to live before the RCD with a resistor (or the other way around). To do the same test to earth, you need a plug tester.

1 hour ago, Steve87 said:

That same earth mandatory pic that was shared by P1000 refers: That external Earth is connected to the main Earth busbar internally. So if the earth of the machine internally was connected, that external earth would not really be required. I think before jumping to conclusions of high proportion please take a pic of the inside earth connections and make sure they make good contact. Im willing to bet that there has been some skipped Earth connections. But the N to E Bridge relay is very important. 

I will open the unit when I get home this afternoon and check the earth connection.  As far as I remember there are 6 wires connected. LNE on input and output.  I might need to trace that earth wire to see where it goes.  Maybe it is disconnected somewhere else.

As far as the E-N bond is concerned.  The setup definitely has one.

Ok.  Hold on to your hats because this is getting interesting.  I opened the front panel of the inverter to check if the earth is attached.  There were 2 wires connected for earth.  One for input and one for output.  I tested for a voltage difference between the earth terminal and the earth bar inside the DB and there was 110vac.  I opened up some of the conduit to traced the wires and found out that they are not connected to anything.  The wires just stop in the middle of the conduit.  The main inverter does not have an earth at all.  I'm guessing this was an oversight as the second inverter has it's earth wires connected to the earth bar in the DB.

Secondly I think the E-N bond is the wrong way round.  i.e. it bonds earth to neutral when Eskom is on and disconnects it when Eskom is off. If I measure for voltage difference between the E and N wires that are connected to the contactor I get basically 0 when Eskom is on and 110v when Eskom is off.  But this is something I am not sure about so please help me here.

Thanks for all the help so far.

After another look it looks like the contactor is fine.  I'm guessing the reading is just weird because one inverter is grounded and the other not. I will ground the inverter and test again.