Practical Real World Question

[steptoe]

Makes me wonder why you couldn't answer it yourself and needed to put it too the forum as a student question? Still I'm glad you found the replies helpful!

the whole purpose of it was to get people thinking,

and it seems some/most people

either

A want to overthink

B dont know how to

 

[Sharpend]

Well that's summed up the country then!

 

[wozz]

right not knocking anyone but:

Using the parameters youve given, BRB table 4D2A tells me the 6mm t+e
will take 46A, and table 4D4A says the 10 SWA will take 67A.

Volt drop on the t+e works out at 4.4mV/A/m x 12m x 46A = 2.428V and on
the SWA 4.4mV/A/m x 12m x 67A = 3.537V so total volt drop = 5.965 or
2.59% of 230v so within tolerance for that.
 
So bearing in mind that the most vulnerable cable will take 46A id use a
45A MCB, the cables dont necessarily need RCD protection, so Id run it
from an unprotected part of the board, rod the shed and have an RCD in
the shed CU.
 
I think it should be  4D5 for the twin, so this throws the VD calcs out.
 
Also VD is worked out using Ib you seem to be using It?

Hi All,

I think everyone has gone a little off track here. I am a bit busy at the mo, but i will have a quick calc and post what i think later tonight if i have time.

In the meantime, what Steps asked is not difficult.... Just approach it as you would if you were doing an EICR...Remember, the cable is already installed... All you need to do it to make the decision "is the OCPD fitted appropriate for the circuit it is protecting" Not difficult...

john...

Im looking upon it as a job, you arrive customers says ive got a old supply to garage can you connect it, and whats size breaker will you be using.

 

[apprentice87]

Have not forgotten.. Will try to post something later, still in a mad rush. All i am saying is that my post WILL be interesting......

john

 

[sprocketflup]

We're waiting........ ^^^^^ (taps foot)