Multiple distribution boards and earthing arrangements

[westward10]

1950ish I should imagine. No reason why is should be a problem unless somehow the armour has degraded.

 

[cliffed]

Any main bonding required in these areas.
Definitely improved situation,but really a poor design originally.
Tt may be the way to go if feasible

 

[Lucien Nunes]

The R/W/B cable could be 1960s, agree there is no particular reason to assume it is U/S.
Also agree that changing the earthing configuration and in particular decreasing the functionality of the installation to deal with a marginal failure would be a pity. Could an alternative type of protective device, such as an adjustable MCCB that could be installed in a separate enclosure if necessary, provide a better compromise between In and max. permitted Zs? Personally, I would have no issue with protection by a fuselink though.

 

[Simon47]

Replacing it is a large and costly project as there is a road and tennis court on top of it now

Just an FYI, there are contractors that do directional drilling. Some years ago at a previous job we looked into using one to link the network across two customer's sites with a road in between. The guy would just dig a pit at both sides, park the drill at one side and put you a duct between the pits - then traditional trenching across the grass from there. As he wasn't interfering with the road structure, no need for a permit etc - I assume he made careful checks of where the other utilities were located before drilling ! I suspect he might not be able to do across a tennis court though.