Rolec SecuriCharge.

[westward10]

Was doing a periodic last week and came across one of these outside a factory. The factory has a TN-C-S earthing system and is connected direct to it using the supply earth.
I have nothing to do with EV points so is this acceptable or will it require an electrode?

 

[UNG]

I've been reading up quite a bit on EV points since the Cenex audit was posted and I would say that it should be TT'ed given that it's on a TN-C-S supply

 

[davesparks]

Unless the bonded steel structure of the factory or lightning protection is acting as a suite earth electrode then yes, earth electrode required.

 

[westward10]

Unless the bonded steel structure of the factory or lightning protection is acting as a suite earth electrode then yes, earth electrode required.

The structural steelwork is bonded so this could satisfy even with the PME earth still connected to the EV unit?

 

[davesparks]

The structural steelwork is bonded so this could satisfy even with the PME earth still connected to the EV unit?

If that structural steel is effectively forming an earth electrode which has a good enough Ra to satisfy the regulations.

In the EV section of the book there are equations to calculate the minimum Ra required.