My and my neighbors property both share an Artesian well and can swop who's power connects to the well via a changeover switch at the well head (also has a central off position).....this is very useful as both are second homes and if one winterizes it allows the other to draw from the well if needed, we both have our own pressure switch and tank etc.

The pump is 240v and has just 2 hot wires and no ground.......my question is that the top of the well head is metal on plastic casing which I wanted to ground (if recommended to do so).

My options as I see it are:

1/ connect to just one of the properties ground wire permently to the well head
2/ connect to both properties ground wires permently to the well head (was not sure if 2 properties could have their ground wires linked together
3/ connect the ground wires into a third set of poles of the changeover switch (as there is one set spare) making ground to the well head with what property is powering the well at that time........only trouble with this option is that when the changeover switch is in the off position, the well head will not be connected to ground which could be 70% of the time

Hope I have made some sort of sense!