There is very little point in insulating the earth marshalling blocks from a shock point of view, as the whole point is that is the voltage that is supposed to be safe to touch. If it isn't then we should insulate all the 'earthed' metal work as well, and then we can retire not just blocks, but the whole idea of earthing, as we have re-invented double insulation...

I can see a merit in earthing being being visible - rather like the earth terminals on the outside of the old "PARcan" theatrical lights in the days when earthing was a new thing and not always done very well (*) - "earthed and seen to be earthed", any failure like missing screws or a wire dropped out was/is immediately visible. For much the same reason I prefer clamps on pipes to be in a place they are immediately on show, as opposed to behind a panel or whatever.  I appreciate that this does not match the aesthetic aspirations of some.

Mike

(*) I know that it was actually the 1939 regs that brought compulsory earthing to power sockets in the UK regs, but for a long time after that it was not seen as that serious a thing, and 2 pin sockets were certainly in use well into the 1970s in older buildings, and theatre installations have historically always been a bit ' keep if going for just one more night'.

PPS A lot of kit for use at very high voltages indeed is NOT insulated, as the insulation would only give a false sense of security and may even be prone to ignition from discharge currents that on a bare wire would either have no effect or just corona.

There is very little point in insulating the earth marshalling blocks from a shock point of view, as the whole point is that is the voltage that is supposed to be safe to touch. If it isn't then we should insulate all the 'earthed' metal work as well, and then we can retire not just blocks, but the whole idea of earthing, as we have re-invented double insulation...

I can see a merit in earthing being being visible - rather like the earth terminals on the outside of the old "PARcan" theatrical lights in the days when earthing was a new thing and not always done very well (*) - "earthed and seen to be earthed", any failure like missing screws or a wire dropped out was/is immediately visible. For much the same reason I prefer clamps on pipes to be in a place they are immediately on show, as opposed to behind a panel or whatever.  I appreciate that this does not match the aesthetic aspirations of some.

Mike

(*) I know that it was actually the 1939 regs that brought compulsory earthing to power sockets in the UK regs, but for a long time after that it was not seen as that serious a thing, and 2 pin sockets were certainly in use well into the 1970s in older buildings, and theatre installations have historically always been a bit ' keep if going for just one more night'.

PPS A lot of kit for use at very high voltages indeed is NOT insulated, as the insulation would only give a false sense of security and may even be prone to ignition from discharge currents that on a bare wire would either have no effect or just corona.

There is very little point in insulating the earth marshalling blocks from a shock point of view

The only situation where I can think it might possibly be helpful, is where it's located (or accessible from) outside the equipotential zone - so say the outdoor meter cabinet with a missing door. Although fixing the cabinet door might be a better solution.

   - Andy.