Hi, I have a concern wrt unearthed neutral using PV cells and inverter as power source. My earth leakage tester shows neutral fault when plugged in and does not trip earth leakage. Your advice will be appreciated. Thanks
My suggestion would be to get an Installation or Master Electrician to come and have a look.
Both of them are certified to work on Solar installations, as not all sparkies are certified to work on solar installations, give a CoC.
OK, I need to decode a little. You say “unearthed neutral using PV cells and inverter as power source”. I decode that as “on the output of my inverter, neutral is not bonded to earth”.
Of course the neutral and earth should be bonded once (and exactly once) in your electrical installation. Your grid connection will already be bonded, so while connected to the grid, you don’t have to do anything.
When running “islanded” (the grid is disconnected, and your loads are powered by an inverter), a TN bond (terra-neutral) must be added for the duration of the islanding. It must be removed again before reconnecting to the grid.
Some inverters do this automatically (Victron). Some do this via additional hardware (sunsynk, dye). Some can do this, but it may not be well documented (Goodwe). Some don’t do it at all (because they were never meant to be installed into a house).
You didn’t say which one you’ve got.
Without a TN bond, an earth leakage won’t work properly, as you observed. You will need TWO earth faults before it trips, and the tester only creates one. The reason for a TN bond is precisely so that a single earth fault will trip the RCD. It makes the install safer.
So… 1) yes, you are right to be concerned, and 2) whether it is even possible to fix this will depend on the hardware you have installed.