Supply for shower board

[madmaz]

been to a job today where a seperate fuseboard has been fitted to supply an 8.5kw shower the supply and load cables for this board are 6.0mm twin and earth, the shower fuseboard has a 32a mcb and an rcd main switch and labelled up shower only, the feed for the seperate fuse board (only room for the one circuit) is 6mm twin and earth direct from the main Fuseboard incoming terminals is this ok ? The main fuse is 60a as the load is fixed at 32a and the 6mm cable is suitable for this the run between consumer units is surface mounted and double insulated less that 300mm long the only protection for the 6mm cable feeding the seperate fuseboard is the main fuse 60a no overloading of this cable is possible as the upstream 32a mcb restricts this the only issue would be a short circuit should the cable be damaged which with the PFC reading 1.2ka this is irrelevant isn't it ? Just wondering, Or have I misunderstood

 

[Wilko]

Hi - FWIW I'm not a happy chap if I arrive at a house to find the DB isolator does not isolate the installation. This is where proper safe isolation procedures really could save my life. Let's hope those guys from Pete's Vids never find that place. If I did work on the house I would try my best to not leave it that way. Cheers, David.

 

[Midwest]

This installation aside, I've seen and worked on numbers of installations with more than one DB, without one isolator. DB's located in the same position. As Lee stated guidance note 2 gives the guidance, and the above is percectly within the regulations, therefore anything else's which may improve the installation is not required and is just personnel preference and opinion, or have I got that wrong?
Only making the point as someone might read this thread, and consider single isolation as mandatory as regards bs7671.

 

[Wilko]

Hi MW, yes I agree. I just reread the OP and now understand the 2 boards are adjacent and labelled

 

[Deleted member 26818]

Yes a building can have more than one installation.
What guidance note 2 doesn't point out, is that the origin of an installation is the customer connection point at the meter.
So a meter with 2 tariffs two connection points, one for normal and the other for off peak would have two installations.
A 3phase meter supplying 3 single phase DBs would have 3 installations.