Bonded earth on Island mode for and inverter

[vincentvanrensburg]

Hi Folks, can anyone shed some light on getting the potential difference down between earth and neutral when installing an Inverter into a home that has no Council or Muncipal mains supply? The issue is here that the Earth is in a floating scenario even if an Earth spike is fitted to the house Distribution board (+-50 Volt between E+N and 170 Volt between L+E). So Bonding the Earth and Neutral would in essence make the Earth Leakage switch redundant as there would be no current leakage between earth and neutral as they would be at the same level? The unit is an Axpert 3000KVA. Any thoughts and help appreciated. Regards Vincent

[frivan]

Earth and neutral have to be bonded somewhere for earth leakages to work in typical home wiring. Usually this point is before the municipal meter.

[vincentvanrensburg]

Hi Frivan. I understand that but there is absolutely no Muncipal feed into the house. So this should be island mode. Then should bonding be done between earth and neutral and if so would the Earth Leakage, then still operate normally?

[Yellow Measure]

Bonding the earth and neutral is essential for the earth leakage  / RCD to function. You will also need at least 3x earth spikes driven into the ground.

Edited April 5, 2023 by YellowTapemeasure

[Yellow Measure]

 

[vincentvanrensburg]

Hello Yellow tape Measure. This is exactly how I understand the concept and need to know how and with what trigger method is best to trigger the relay and to have the RCD to function correctly. Keeping in Mind that there is no Municipal feed and only Solar and if need be, a Generator to charge the batteries in cloudy weather.

[Steve87]

There are a couple of ways to trigger the Relay. Some Sunsynk Models have the ATS240 which is essentially a signal Islanding mode ✓ that needs to be checked to function. What it does is send a 240V signal to a suitable relay to tie the Neutral & Earth together. However, in my opinion since you do not have Grid power that bond can be permanent. 

So if a grid was present you can use a Contactor to carry out the function a NO contactor. Or in the case of the inverter does not have the AtS240 then a 240V relay that has both functions NO & NC will do the trick. 

[vincentvanrensburg]

Awesome. Thank you for the information. Really has shed light on the problem.