immersion fault on solar systems

[solec]

hello, we are having problems with some immersions that are tripping rcd`s when the earth is connected but are working fine without the earth connected. Some immersions are from China and some are from Spain(where we install) can anyone help.

 

[breezer]

you seem to have answered your own question.

the elements would seem to have an earth fault.

have you tried an insulation resistance tester on them?