Hi. 

After a whole day of fault finding, turns out my axpert is somehow giving me a earthing voltage. 

With no input or output wires connected. I measure 80-100vac from earth to negative on both ac input and output terminals on the inverter. 

Surely this is not correct? My earth leakage doesn't pick it up, but does trip occasionally/frequently. 

Any advise is appreciated. 

Pete

 

 

14 hours ago, Petum said:

Hi. 

After a whole day of fault finding, turns out my axpert is somehow giving me a earthing voltage. 

With no input or output wires connected. I measure 80-100vac from earth to negative on both ac input and output terminals on the inverter. 

Surely this is not correct? My earth leakage doesn't pick it up, but does trip occasionally/frequently. 

Any advise is appreciated. 

Pete

 

 

Your earth is floating with respect to neutral.  It'll give you spurious readings.  When on inverter power your neutral and earth needs to be bonded at the inverter output.

14 hours ago, Petum said:

My earth leakage doesn't pick it up, but does trip occasionally/frequently. 

Unlikely to be related to the inverter.  You almost certainly have a wiring fault or device that has high leakage.  Alternatively whatever is causing the high voltage to develop on your earth wire could be tripping it once power comes back and you switch to grid power.

Would this solve my issue? 

https://www.bonanzatech.co.za/index.php?id_product=9568&rewrite=grounding-box-for-axpert-inverters&controller=product

Then change program 38?

On 2021/12/06 at 2:43 AM, Petum said:

I measure 80-100vac from earth to negative on both ac input and output terminals on the inverter. 

Surely this is not correct?

Actually, it is correct. There are small EMI suppressing capacitors from L and N  (in and out) to earth. So you'll get basically a voltage divider between L and N, and then another voltage divider between that centre tap and your multimeter. So 240 → 120 → ≈80 VAC.

On 2021/12/06 at 6:29 PM, Petum said:

Would this solve my issue? 

That's only needed for older Axperts that don't have the automatic earth to neutral bonding, and then only if the neutrals are not connected together.

On 2021/12/06 at 2:43 AM, Petum said:

My earth leakage doesn't pick it up, but does trip occasionally/frequently. 

If your earth leakage breaker is before the inverter, then that will tend to trip occasionally, depending on how much other leakage there is from live to earth elsewhere (usually from loads plugged in and turned on). There should be a residual current breaker with overload (RCBO, though names vary) on the output of the inverter, to protect people and animals from electrocution.

If your RCBO is on the output of the inverter and still nuisance trips, and it's not because of other loads, then you likely have more than one connection from neutral to earth in your system, which causes some load current to flow through earth conductors. This will cause trips.

On 2021/12/06 at 10:29 AM, Petum said:

Would this solve my issue? 

https://www.bonanzatech.co.za/index.php?id_product=9568&rewrite=grounding-box-for-axpert-inverters&controller=product

Then change program 38?

I have no idea what that thing does 😛 I just made my own earth relay.  Maybe contact the company that makes it?