Installation g100 is a safety feature that we put on the zappi to make sure that it always keeps connected to a hardwired grid ct clamp.
If you are getting this message, it means that the zappi has 1 or more of the ct clamps set to grid, and it has nothing connected to the part of the zappi. Probably a harvi was used.
  1. Go to the zappi menu please, 
  2. other settings, advanced (password0000), 
  3. Ct config
If you have the Harvi installed physical in the Fuse board or in the ESB box, can you Disable all CT1,CT2 & CT3 please?
If you dont have Harvi installed with the Zappi, can you
Can you check that only CT1 enabled and set to grid, while CT2 and CT3 should be disabled?
IF you have Single Phase power, but CT2 and CT3 enabled,  you need to Disable Them.
please press +, then Press + again and use the up and down arrow to set it to none. that should stop it from coming up with this error when charging.
Once you completed this,
Save it
Go out to the main menu, where you see the Solar + House + Car Symbols and the G100 should disappear.
If the G100 Error message still appear, please restart the Zappi with the Red AC Isolator located next to it.