Prospective Earth Fault Current

[Sparky12021986]

can anybody help me with this question?

Why is Prospective Earth Fault Current important during the design stage of an electrical installation..

 

[GT1]

For the same reason as prospective short circuit current is important...

Find out the actual figure by enquiry with the DNO or measure it at origin of the installation.

 

[malcolmsanford]

As a fault current in any installation will be the largest current ever expected that installation to be designed for, knowing that current will enable you to choose a protective device capable of safely breaking that current in the prescribed time .

Have a read of section 434 of the regs

 

[Sparky12021986]

As a fault current in any installation will be the largest current ever expected that installation to be designed for, knowing that current will enable you to choose a protective device capable of safely breaking that current in the prescribed time .

Have a read of section 434 of the regs

Special thanks to malcolmsanford for such a straight answer thank you...

P.S. what Regs book are you reading..

 

[malcolmsanford]

Bs 7671

 

[telectrix]

and also to size the protective conductor csa.

 

[Sparky12021986]

Bs 7671

Would that be 17th edition if so thank you because thats the 1 that i got...

 

[telectrix]

that's the only one you should have. from jan 1st 2012, should be the green version.

 

[Sparky12021986]

that's the only one you should have. from jan 1st 2012, should be the green version.

Nah mine is red and is from last may when i got it.. how much and where can i get the new green 1 from thanks...

 

[malcolmsanford]

Requirements for Electrical Installations: BS 7671:2008 Incorporating Amendment No 1: 2011: IET Wiring Regulations: Amazon.co.uk: Institution Of Engineering And Technology: Books

 

[Sparky12021986]

Ahh sweet thanks..