A dunce question from me

[DavidJ91]

How do you use tabulated current to work out suitable cable size?

I do own a copy of the 17th Edition IEE Wiring Regs but to a noobie Level 2 student like me, the tables in it make me confused.com sometimes, particularly with correction factors.

I'd appreciate any help

 

[Sparky Ninja]

Tabulated current = It

Go through Appendix 4 and select the nearest size cable that accommodates this current level. This cable's CCC becomes Iz.
Assess your selected cable for voltage drop, and if within tolerance then you've got your size. If not, select the next cable up, assess VD again and repeat till successful.

Do you know how to obtain It?

 

[DavidJ91]

...Do you know how to obtain It?

Yes. It = In/(Correction factors).

 

[mayfair]

No such thing as dunce question m8 if you dont know the answer ask..............Now as for silly questions, thats a different story

 

[Sparky Ninja]

Yes. It = In/(Correction factors).

You're all set then.

 

[pushrod]

Biggest problem can be finding the correct table if you are unsure of your way around it (BS7671) - Table 4D5 (page 282) is a useful one as it especially for twin and earth plus it has the volt drop/metre in the last column