turning outbuilding into office

[jase]

have calculated mx demand to be 60A with diversity
1x32 ring
1x16 radial supply to hand 3kw hand wash unit
1x 6A lighting circuit

gonna put 63A 30mA main breaker in 5 way fuseboard fed by 10mm 2 core swa and TT it
swa run would be 35M from house.
would it be advisable to put this on an mcb in the house cu? 63 a breaker?
or which i think is better option, spilt tails in henley block, earth armoured in MET and out 63A switched fuse in?

been reading alot of posts on here and seems there are alot of 63A 30mA boards being fed by 40A mcb, how so?

 

[jase]

have calculated mx demand to be 60A with diversity
1x32 ring
1x16 radial supply to hand 3kw hand wash unit
1x 6A lighting circuit

gonna put 63A 30mA main breaker in 5 way fuseboard fed by 10mm 2 core swa and TT it
swa run would be 35M from house.
would it be advisable to put this on an mcb in the house cu? 63 a breaker?
or which i think is better option, spilt tails in henley block, earth armoured in MET and out 63A switched fuse in?

been reading alot of posts on here and seems there are alot of 63A 30mA boards being fed by 40A mcb, how so?

actually max demand is less than 60A due to lighting circuit but only marginally

 

[Guest123]

As you've said, split the tails, feed into a new MC 60A switchfuse to supply your new office with a new DB in the office.


If TN-S system then no need to TT it at all, if TN-C-S again no need for TT but other criteria must be satisfied so may be easier in this instance to TT it.