TT submain to summerhouse

[Sibo14]

hi all,


Looking for opinions for a job I’ve been asked to do.

Supply to summer house\workshop approx 8m away. TT system as out in the sticks. They want a couple of sockets and lights so going to give them a 25amp supply

House cu is split load job which is full and dosen't have a 100ma main switch.

Current plan:

Split tails and install small cu with 100ma s type rcd and mcb at house end.

2 or 3 core swa buired direct to another cu in the summerhouse with 30ma rcd and mcbs as required.

no bonding required at summerhouse but add second earth rod depending on the readings.

Other way i thought of doing it to reduce the cost slightly was use a 30ma rcbo at the house and jused fused spur for the lights in the summerhouse.

any thoughts?

 

[Risteard]

I would have the S-type RCD at the origin of the installation so that it is protecting everything including the tails (apart from the DNO's tails from the meter).

I also wouldn't use a circuit breaker - a switch fuse would be a much better solution.

 

[Gavin John Hyde]

Agree with above ^^^ about the switch fuse being more appropriate. It would give added protection. You can choose the rating of the fuse to suit your designs

 

[bigspark17]

How do you come to 25a required out of interest?
You should put the Stype covering the whole install, is bonding in the house in place?
I would run a 3c 10mm in these instances.