Bs 88-3

[jdd]

Is a 100A BS 88-3 fuse suitable for being the service fuse in a TN-S system with a Ze reading of say 0.68.

Obviously a TN-S system will be quoted at 0.8, but I just worked out the maximum Zs on this 100A fuse to be 0.38?

Your thoughts...

 

[Darkwood]

What kind of installation is it, i see these used in ISU boxes on commercial and industrial and gives discrimination to BS88-2 if same rated and fitte downstream, ps how do you know what the service head fuse is

 

[Deleted member 26818]

Your supplier may allow it, but unless your Zs is less than 0.38Ω, you'll have to install an RCD for earth fault protection.
The supplier will most probably want to change the supply to TN-C-S.