this formulea

[bushynut]

Iz = In
C

The above is a formulea for calculating cable size I understand what Iz is and In. But I am having trouble trying to work work out what 'C' stands for.
I know its for correction factors.

The cable calculation is going to be for multi core 70 degree armoured thermoplastic (pvc) insulated cables (copper).

The cable calcs are for revision for my exam in 4 weeks time.
the values for C given is 1.03 in the equation any ideas where i can find that factorr value?
the cable calc is for a 126 metre run for lighting columns in a car park.

Thanks in advance

 

[bushynut]

the 'C' should be under the In

 

[Spark123]

I think what you are getting at is Iz=> In=> Ib;
Iz is the current carrying capacity of the cable (after correction factors)
In is the nominal setting of the protection device
Ib is the design current of the circuit.

correction factors are;
Cg = grouping
Ca = ambient
Ci = thermal insulation
Cr = rewirable fuses

To calculate the minimum required current carrying capacity of the cable Iz = In/(Cg x Ca x Ci x Cr)

 

[bushynut]

of course yes lol dear god how dumb was I. and just think by xmas i'll have my JIB card, be worried!

thanks man appreciatte it

 

[Spark123]

Which course are you doing?