431.2.1 again

[Jeffmo65]

Commercial scenario :
lets say 54m , mmm ok 16amp OCPD, mmm ok at 52m I think I will put a 20amp D/P isolator , humour me I will go on . Actually oh dear I've ran out of 4mm T/E , tell you what I will just use 2.5mm instead . Anybody see an issue , cable clear run on open spacious cable tray no influences just straight clear run .
I just know that someone will say it's fine cos 2.5mm will take 25 odd amps .
Conversations requested guys

 

[Leesparkykent]

Mmmmmm

 

[Bobster]

Under new rules I'm sure trolling is worth a 3month ban.

 

[ruston]

Under new rules I'm sure trolling is worth a 3month ban.

Or 2-5 months

 

[Bobster]

Or 2-5 months

I see what you did there! Haha

 

[Jeffmo65]

Sorry guys not sure really what you mean . If I've broken some rules then I apologise . Oh and the cable size is after the isolator NOT A FUSED SPUR by the way

 

[ruston]

Lol , don't worry about it , some start posts like this as a wind up , but it has fallen out of favour in the last few days.

 

[Plonker 3]

So do VD,Zs and CCC comply with BS7671?

 

[Jeffmo65]

Oh good ,! Thought I was for the high jump . Anyway any views on my scenario ?.....

 

[Jeffmo65]

Oh don't worry about VD it's irrelevent ............ Isn't it . Let's see 2.5mm ooh about 40m max . 4mm what about 60 odd . Oh B type MCB BS60898 Schneider acti 9 10ka . Oh bugger lets just put the last few meters in 2.5mm

 

[ruston]

There again.......................

 

[Plonker 3]

Have you carried any calcs out to prove it doesnt comply?

 

[Jeffmo65]

Hi Dillb . Well this is purely a scenario but I would have thought that the length if you were to carry on from isolator with 4mm then great but this wasn't the question . I've seen lots of installations where other sparks have ran circuit in X cable to an isolator then for some unbeknown reason dropped to cable Y . My question is why not run the whole lot in cable Y if it's ok to use this on the last few meters . I think not . What's your thoughts ?.....??????

 

[Plonker 3]

Have you got some reg numbers to back up your thoughts?

 

[Jeffmo65]

431.2.1 ????

 

[Leesparkykent]

431.2.1 ????

What about it?

 

[Plonker 3]

What???

As long as the neutral conductor can carry the current without overloading then there is no problem

 

[Richard Burns]

Too slow

 

[Jeffmo65]

So voltage drop has nothing to do with it then ????

 

[Plonker 3]

So voltage drop has nothing to do with it then ????

What you going on about?