Alright this was kinda interesting. apart from the solar installation, the client also has a backup system for his geyser with a pc board in the db allowing the sun to heat up the water and if it's inadequate to reach the required temperature, it also takes from the grid the power it requires and it also has a bypass circuit breaker. when i bypass this pc board and switch off the grid to the home, the inverter changes over fine and nothing trips but when the pc board is not on bypass and i switch off the grid, it trips out the main switch which is the 3 phase earth leakage. So he is getting the guys out that did the geyser installation and he was so happy that he now wants 3 solar quotes on 3 of his 10 game farms urgently whoop whoop!