High Ze on PME question

[Gavin John Hyde]

Come across this on instagram this morning.
Any thoughts? Dont have much experience of generators myself,
In terms of this question my thoughts were additonal or secondary supply source with a rod skewing readings? Not sure though. Would somebody with experience of generators explain?

 

[Wilko]

Hi All, bit late to this party, but it sounds so interesting .
Terrific diagram @Richard Burns !
Just a comment - I've not seen a user of standby power systems remove that link between the two earthing systems. Maybe I just haven't looked hard enough?

 

[Lucien Nunes]

I'm also thinking that the DNO MET link is open. If it's a serious generator installation, it might have a decent earth grid or there might be extraneous conductive parts in contact with the genny (pipework etc) that are still in parallel, i.e. it's not a true Ze while the genny is connected. As stated, this would be running as TN-S on the genny but a sneaky TT on the DNO supply.